Optimizing LDMOS Transistors Bias Control: Developing An Accurate Solution for Basestation RF Power Amplifiers

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Optimizing LDMOS Transistors Bias Control: Developing An Accurate Solution for Basestation RF Power Amplifiers"

Transcription

1 Optimizing LDMOS Transistors Bias Control: Developing An Accurate Solution for Basestation RF Power Amplifiers RF power amplifiers with LDMOS and GaAs transistors can provide excellent performance but require temperature-compensated bias circuitry By Jim Pflasterer, Intersil Corporation LDMOS transistors are used for RF Power Amplification in numerous communications applications, notably cell phone basestations. RF Power Amplifiers (RFPAs) provide from 5 W to over 1000 W of output power per channel and require extremely good linearity to maximize the data throughput in a given channel. The main consideration in achieving that linearity is the DC biasing of the LDMOS transistor. The drain current bias (I dd ) needs to be held constant over temperature and time for optimal performance. Typically the target accuracy for I dd bias current over temperature is +/-5%. I dd bias drift in a typical class AB amplifier will result in reduced power output, increased distortion products and reduced phase linearity, all of which impair the performance in digital communications systems. The DC Bias on these amplifiers is set by applying a DC voltage to the gate (V gs ) and monitoring the I dd current. Ideally, this I dd will be constant over temperature, but since the V gs of LDMOS amplifier devices varies with temperature, some type of temperature compensation is required. One method of setting this DC bias involves using an adjustable reference, DAC, or digital potentiometer combined with a temperature compensation source, such as a transistor V be multiplier. This solution can work well, but getting tight temperature compensation can be problematic since the V be junction-temperature characteristic for discrete transistors will vary. Also, the V gs temperature coefficient (tempco) for LDMOS amplifiers will vary with I dd. The result: there are variations in V be junction characteristics as well as the LDMOS characteristics. For optimal temperature compensation, in-circuit calibration and adjustments need to be made for both the temperature compensation as well as the V gs room temperature bias. An integrated bias and temperature-compensation solution An alternative solution is available to provide a very accurate DC bias design. It involves a programmable bias and temperature-slope device, in conjunction with a two-temperature calibration procedure. One basic requirement for this solution is an analog output-temperature sensor which is programmable for both DC output voltage and temperature slope. Two voltage-reference blocks are used to produce both a constant output voltage (1.20 V) and a temperature-slope output. These two outputs pass through scaling DACs and are summed inside the device, producing a single DC

2 voltage. That DC voltage passes through a variable gain stage with gains of 1, 2 or 4, and the output goes to the V out pin. The DC level, PTAT, and Gain parameters are programmed via the I 2 C bus interface, with byte level control, Figure 1. Scaling (DAC) 1.20V Reference x (n/255) Sum Gain n = 0 to 255 Vout -2.1mV/deg C Temp slope Generator x (-m/255) to x (+m/255) m = 0 to 255 Av = 1, 2, 4 I2C interface And Control Figure 1. Block Diagram of a DC Bias Design Solution The DC voltage reference output is 1.20 V nominal, and with a 5.0 V supply the output range for the device is 0.10 V to 4.8 V. The nominal temperature slope is -2.1 mv/ C, and the scaling DAC adds positive tempco scaling to give a range of +/-2.1 mv/ C. Including the gain stage, this provides for up to +/-8.4 mv/ C temperature slope. This is scaled for both positive and negative slopes with 8 bits of resolution from the slope control, Figure A V = V RE F (V) TS = 0 TS = 127 A V = 1 TS = TS = 0 TS = 127 TS = TEMPERATURE ( C) Figure 2. Variable DC Point and Temperature Slope Output The ideal device should be well-suited to temperature compensation functions, enabled by slope programmability and 2% accuracy of the temperature sensing function. The independently programmable DC and temperature slope components allow a custom linear control function. The voltage output is capable of driving nominal resistive loads with up to 0.5 ma of DC output current and can handle up to 500 pf of capacitive load. These characteristics are well suited to

3 LDMOS applications where the output voltage is isolated from any capacitive load with a small resistor and the bias current required is negligible. Figure 3. RFPA Bias Control with the Intersil ISL RFPA bias control using the ISL21400 is very straightforward. The basic schematic is shown in Figure 3. The dashed rectangle highlights the RFPA circuit using an MRF9080 from Freescale 1. The maximum supply voltage for the ISL21400 (U2) is 5.5 V and U1 drops the LDMOS V dd supply from +26 V to +5.0 V for the U2 V cc supply. An LC filter is added to the U2 V cc supply to ensure no RF energy is present on that supply line. The ISL21400 output is connected to the LDMOS gate through a lowpass filter which blocks any RF energy from reaching the ISL A series 100- output resistor (R2) isolates the filter capacitor from the V out pin to insure stability. Also, R2 allows a simple shutdown circuit to be added with Q2 and R3, which will provide a soft LDMOS gate clamp when the shutdown (SHDN) input is brought high (>2 V). An open drain inverter or buffer can be used as well as long as the leakage current at high temperatures is not excessive.

4 The ISL21400 SCL and SDA lines can be tied to a local microcontroller or to an I/O connector for external PC control and programming. The A0, A1, A2 pins are all tied to ground giving an I 2 C slave address of x, where x is the read/write-bit. This entire circuit was implemented on an RFPA evaluation board with the MRF9080. The ISL21400 is placed adjacent to the LDMOS device to get best temperature tracking. The register programming is done using an Intersil PC-based USB eval board (ISLUSBCEVAL1Z) which has lines for SCL/SDA, and special ISL21400 GUI software. The board is disconnected for testing in a temperature chamber Calculating register values In this circuit, the N-channel LDMOS transistor gate has approximately a -2.8 mv/ C temperature coefficient from -10 C to +85 C. A constant-bias drain current is desired, with a target V gs range derived from the data sheet of 2.5 V to 3.5 V at 25 C. To set V OUT offset while targeting V OUT =3.0 VDC, note that: V OUT (DC) = (Av x Vref x Aref) = 3.00V; (Aref = DAC scaling value for DC level, from 0 to 1) and Vref = 1.20V. Simplifying, we find that Av x Aref = Since Aref varies from 0 to 1, and the choices for Av are 1, 2 and 4, we must use Av = 4. We plug our choice back in to find Aref = 2.5/4 = = n/255, meaning n = 159 decimal or 9F hex. The variable n is set at the register address 00h, and the variable Av is in the gain register at address 02h. Using the equation for temperature slope, we can solve for slope directly, since V OUT (TS) = Av x K x Aptat = -2.8 mv/ C; (Av is set to 4, above, and K=-2.1, constant). Aptat = = ((2xm)-255)/255, so m = 170 decimal or A9 hex. The variable m is set at the register address 01h. The device is then programmed with these parameters for initial testing. Actual system testing would involve powering up the system and verifying bias current settings. Adjustments to register settings can then be made to fine tune amplifier performance. Note that since V gs drift is not perfectly linear with temperature at higher temperatures, the I DS bias error will increase at the temperature extremes due to this nonlinearity. Bench test results The amplifier platform was powered up with the V GG (LDMOS gate) voltage clamped in shutdown mode until the ISL21400 was powered up and programmed. The initial setting for V GS =3.0V was too low for the target value of I DD =600 ma at room temperature, so the value for n was increased until a suitable I DD close to the target was reached. The final register setting was n = B0h. The amplifier platform including the bias control circuit was placed in a temperature chamber and tested from 24 C ambient to 65 C. The bias current was monitored (RF power OFF and

5 input/output terminated in 50 ) and the results are shown in Figure 4. V GG bias voltage was monitored with a voltmeter tied to the drain of Q2 to limit any parasitic effects on the LDMOS gate. The result is plotted in Figure 4 and the error from ideal is shown in Figure 5. Figure 4. Measured Drain Current vs. Temperature Figure 5. Drain Current Error vs. Temperature The amplifier stays within the +/-5% limits fairly consistently, meeting the design goals. The initial setting for bias at 25 C appears somewhat high at 620mA (compared to target of 600 ma) but this is limited by the resolution of the ISL21400 at the gain=4 setting. The next lowest offset level results in a bias of about 565 ma, which is too low. The higher temperature range, above 60 C, will tend to show more error normally, due to the higher nonlinearity as noted earlier. Careful attention to the overall error curve and adjustment allows compensation to keep that error within the maximum limits. One thing to note in this design, or any that requires temperature compensation, is the mechanical properties of the board mounting and the cooling system. In this example, airflow over the LDMOS device and the temperature sensor was limited, which enhanced the resulting compensation. Also, the ISL21400 device was surface mounted with conductive grease next to the LDMOS device. In many designs, precise control over placement and airflow is not possible, but since calibration takes place after the assembly of the unit, these effects can be minimized as long as the final installation is similar to the calibration conditions. LDMOS amplifiers also have a characteristic I dd drift over time (drain current reduces for a given V gs ), as well as temperature. This can be addressed with either recalibration or by purposely setting the I DD bias high, knowing the drift will be in the negative direction.

6 Conclusions RF power amplifiers with LDMOS and GaAs transistors can provide excellent performance but require temperature compensated bias circuitry. A programmable, linear-temperature compensation device is capable of producing bias control and simplifying that circuitry. The biascurrent accuracy possible is within 5% of target value, which permits low distortion over the temperature range. References 1. Freescale Semiconductor; 2. Intersil Corporation;

Peggy Alavi Application Engineer September 3, 2003

Peggy Alavi Application Engineer September 3, 2003 Op-Amp Basics Peggy Alavi Application Engineer September 3, 2003 Op-Amp Basics Part 1 Op-Amp Basics Why op-amps Op-amp block diagram Input modes of Op-Amps Loop Configurations Negative Feedback Gain Bandwidth

More information

Conversion Between Analog and Digital Signals

Conversion Between Analog and Digital Signals ELET 3156 DL - Laboratory #6 Conversion Between Analog and Digital Signals There is no pre-lab work required for this experiment. However, be sure to read through the assignment completely prior to starting

More information

Digital to Analog Converter. Raghu Tumati

Digital to Analog Converter. Raghu Tumati Digital to Analog Converter Raghu Tumati May 11, 2006 Contents 1) Introduction............................... 3 2) DAC types................................... 4 3) DAC Presented.............................

More information

Application Note 142 August 2013. New Linear Regulators Solve Old Problems AN142-1

Application Note 142 August 2013. New Linear Regulators Solve Old Problems AN142-1 August 2013 New Linear Regulators Solve Old Problems Bob Dobkin, Vice President, Engineering and CTO, Linear Technology Corp. Regulators regulate but are capable of doing much more. The architecture of

More information

LM 358 Op Amp. If you have small signals and need a more useful reading we could amplify it using the op amp, this is commonly used in sensors.

LM 358 Op Amp. If you have small signals and need a more useful reading we could amplify it using the op amp, this is commonly used in sensors. LM 358 Op Amp S k i l l L e v e l : I n t e r m e d i a t e OVERVIEW The LM 358 is a duel single supply operational amplifier. As it is a single supply it eliminates the need for a duel power supply, thus

More information

Junction Field Effect Transistor (JFET)

Junction Field Effect Transistor (JFET) Junction Field Effect Transistor (JFET) The single channel junction field-effect transistor (JFET) is probably the simplest transistor available. As shown in the schematics below (Figure 6.13 in your text)

More information

Designing interface electronics for zirconium dioxide oxygen sensors of the XYA series

Designing interface electronics for zirconium dioxide oxygen sensors of the XYA series 1 CIRCUIT DESIGN If not using one of First Sensors ZBXYA interface boards for sensor control and conditioning, this section describes the basic building blocks required to create an interface circuit Before

More information

Temperature Sensors. Resistance Temperature Detectors (RTDs) Thermistors IC Temperature Sensors

Temperature Sensors. Resistance Temperature Detectors (RTDs) Thermistors IC Temperature Sensors Temperature Sensors Resistance Temperature Detectors (RTDs) Thermistors IC Temperature Sensors Drew Gilliam GE/MfgE 330: Introduction to Mechatronics 03.19.2003 Introduction There are a wide variety of

More information

ADC-20/ADC-24 Terminal Board. User Guide DO117-5

ADC-20/ADC-24 Terminal Board. User Guide DO117-5 ADC-20/ADC-24 Terminal Board User Guide DO117-5 Issues: 1) 8.11.05 Created by JB. 2) 13.12.05 p10: added 0V connection to thermocouple schematic. 3) 22.3.06 p11: removed C1. 4) 20.8.07 New logo. 5) 29.9.08

More information

What Does Rail-to-Rail Operation Really Mean?

What Does Rail-to-Rail Operation Really Mean? What Does Rail-to-Rail Operation Really Mean? 2004 Microchip Technology Incorporated. All Rights Reserved. What does Rail-to-Rail Operation really mean? 1 Agenda What does Rail-to-Rail output operation

More information

www.jameco.com 1-800-831-4242

www.jameco.com 1-800-831-4242 Distributed by: www.jameco.com 1-800-831-4242 The content and copyrights of the attached material are the property of its owner. LF411 Low Offset, Low Drift JFET Input Operational Amplifier General Description

More information

Pressure Transducer to ADC Application

Pressure Transducer to ADC Application Application Report SLOA05 October 2000 Pressure Transducer to ADC Application John Bishop ABSTRACT Advanced Analog Products/OpAmp Applications A range of bridgetype transducers can measure numerous process

More information

CA723, CA723C. Voltage Regulators Adjustable from 2V to 37V at Output Currents Up to 150mA without External Pass Transistors. Features.

CA723, CA723C. Voltage Regulators Adjustable from 2V to 37V at Output Currents Up to 150mA without External Pass Transistors. Features. CA73, CA73C Data Sheet April 1999 File Number 788. Voltage Regulators Adjustable from V to 37V at Output Currents Up to 1mA without External Pass Transistors The CA73 and CA73C are silicon monolithic integrated

More information

Chapter 8:Field Effect Transistors (FET s)

Chapter 8:Field Effect Transistors (FET s) Chapter 8:Field Effect Transistors (FET s) The FET The idea for a field-effect transistor (FET) was first proposed by Julius Lilienthal, a physicist and inventor. In 1930 he was granted a U.S. patent for

More information

Operational Amplifiers

Operational Amplifiers perational Amplifiers. perational Amplifiers perational amplifiers (commonly known as opamps) are integrated circuits designed to amplify small voltages (or currents) to usable levels. The physical packaging

More information

Understanding the Terms and Definitions of LDO Voltage Regulators

Understanding the Terms and Definitions of LDO Voltage Regulators Application Report SLVA79 - October 1999 Understanding the Terms and Definitions of ltage Regulators Bang S. Lee Mixed Signal Products ABSTRACT This report provides an understanding of the terms and definitions

More information

Environmental Monitoring with Sensors: Hands-on Exercise

Environmental Monitoring with Sensors: Hands-on Exercise Environmental Monitoring with Sensors: Hands-on Exercise Now that you ve seen a few types of sensors, along with some circuits that can be developed to condition their responses, let s spend a bit of time

More information

Digital-to-Analog Conversion

Digital-to-Analog Conversion Digital-to-Analog Conversion Curtis A. Nelson Engr355 1 Introduction Connecting digital circuitry to sensor devices is simple if the sensor devices are inherently digital themselves. Switches, relays,

More information

Voltage Output Temperature Sensor with Signal Conditioning AD22100

Voltage Output Temperature Sensor with Signal Conditioning AD22100 Voltage Output Temperature Sensor with Signal Conditioning AD22100 FEATURES 200 C temperature span Accuracy better than ±2% of full scale Linearity better than ±1% of full scale Temperature coefficient

More information

LM148/LM248/LM348 Quad 741 Op Amps

LM148/LM248/LM348 Quad 741 Op Amps Quad 741 Op Amps General Description The LM148 series is a true quad 741. It consists of four independent, high gain, internally compensated, low power operational amplifiers which have been designed to

More information

Operational Amplifiers: Part 2. Non-ideal Behavior of Feedback Amplifiers DC Errors and Large-Signal Operation

Operational Amplifiers: Part 2. Non-ideal Behavior of Feedback Amplifiers DC Errors and Large-Signal Operation Operational Amplifiers: Part 2 Non-ideal Behavior of Feedback Amplifiers DC Errors and Large-Signal Operation by Tim J. Sobering Analog Design Engineer & Op Amp Addict Summary of Ideal Op Amp Assumptions

More information

Chapter 19 Operational Amplifiers

Chapter 19 Operational Amplifiers Chapter 19 Operational Amplifiers The operational amplifier, or op-amp, is a basic building block of modern electronics. Op-amps date back to the early days of vacuum tubes, but they only became common

More information

DS1621 Digital Thermometer and Thermostat

DS1621 Digital Thermometer and Thermostat Digital Thermometer and Thermostat www.dalsemi.com FEATURES Temperature measurements require no external components Measures temperatures from 55 C to +125 C in 0.5 C increments. Fahrenheit equivalent

More information

LM1036 Dual DC Operated Tone/Volume/Balance Circuit

LM1036 Dual DC Operated Tone/Volume/Balance Circuit LM1036 Dual DC Operated Tone/Volume/Balance Circuit General Description The LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems.

More information

Designing a Poor Man s Square Wave Signal Generator. EE-100 Lab: Designing a Poor Man s Square Wave Signal Generator - Theory

Designing a Poor Man s Square Wave Signal Generator. EE-100 Lab: Designing a Poor Man s Square Wave Signal Generator - Theory EE-100 Lab: - Theory 1. Objective The purpose of this laboratory is to introduce nonlinear circuit measurement and analysis. Your measurements will focus mainly on limiters and clamping amplifiers. During

More information

Operational Amplifiers

Operational Amplifiers Operational Amplifiers Introduction The operational amplifier (op-amp) is a voltage controlled voltage source with very high gain. It is a five terminal four port active element. The symbol of the op-amp

More information

MOSFET transistor I-V characteristics

MOSFET transistor I-V characteristics MOSFET transistor I-V characteristics Linear region: v DS «v GS Triode region: v DS < v GS i D = K[ 2( v GS )v DS ] 2 i D = K[ 2( v GS )v DS v DS ] K n K = = C ox µ n W ----- K 2L n v DS = v GS sat (current)

More information

School of Engineering Department of Electrical and Computer Engineering

School of Engineering Department of Electrical and Computer Engineering 1 School of Engineering Department of Electrical and Computer Engineering 332:223 Principles of Electrical Engineering I Laboratory Experiment #4 Title: Operational Amplifiers 1 Introduction Objectives

More information

BIASING MMIC AMPLIFIERS (e.g., ERA SERIES) (AN )

BIASING MMIC AMPLIFIERS (e.g., ERA SERIES) (AN ) Introduction BIASING MMIC AMPLIFIERS (e.g., ERA SERIES) (AN-60-010) The Mini-Circuits family of microwave monolithic integrated circuit (MMIC) Darlington amplifiers offers the RF designer multi-stage performance

More information

Tire pressure monitoring

Tire pressure monitoring Application Note AN601 Tire pressure monitoring 1 Purpose This document is intended to give hints on how to use the Intersema pressure sensors in a low cost tire pressure monitoring system (TPMS). 2 Introduction

More information

Application Note AN10174-01. A Low Impedance PIN Diode Driver Circuit with Temperature Compensation

Application Note AN10174-01. A Low Impedance PIN Diode Driver Circuit with Temperature Compensation Application Note AN74- A Low mpedance PN Diode Driver Circuit with Temperature Compensation Two Philips BAP5 PN diodes are used in an RF attenuator with a low impedance driver circuit to significantly

More information

Analog Devices Welcomes Hittite Microwave Corporation NO CONTENT ON THE ATTACHED DOCUMENT HAS CHANGED

Analog Devices Welcomes Hittite Microwave Corporation NO CONTENT ON THE ATTACHED DOCUMENT HAS CHANGED Analog Devices Welcomes Hittite Microwave Corporation NO CONTENT ON THE ATTACHED DOCUMENT HAS CHANGED www.analog.com www.hittite.com THIS PAGE INTENTIONALLY LEFT BLANK Typical Applications The is ideal

More information

Real Time Clock USB Evaluation Board V3.0

Real Time Clock USB Evaluation Board V3.0 Real Time Clock USB Evaluation Board V.0 Application Note February 9, 008 RTC EVB Intersil RTC Devices Supported Introduction This evaluation board provides a platform for testing Intersil Real Time Clock

More information

Constant Voltage and Constant Current Controller for Adaptors and Battery Chargers

Constant Voltage and Constant Current Controller for Adaptors and Battery Chargers TECHNICAL DATA Constant Voltage and Constant Current Controller for Adaptors and Battery Chargers IK3051 Description IK3051 is a highly integrated solution for SMPS applications requiring constant voltage

More information

WHAT DESIGNERS SHOULD KNOW ABOUT DATA CONVERTER DRIFT

WHAT DESIGNERS SHOULD KNOW ABOUT DATA CONVERTER DRIFT WHAT DESIGNERS SHOULD KNOW ABOUT DATA CONVERTER DRIFT Understanding the Components of Worst-Case Degradation Can Help in Avoiding Overspecification Exactly how inaccurate will a change in temperature make

More information

Features. Symbol JEDEC TO-220AB

Features. Symbol JEDEC TO-220AB Data Sheet June 1999 File Number 2253.2 3A, 5V,.4 Ohm, N-Channel Power MOSFET This is an N-Channel enhancement mode silicon gate power field effect transistor designed for applications such as switching

More information

Description. 5k (10k) - + 5k (10k)

Description. 5k (10k) - + 5k (10k) THAT Corporation Low Noise, High Performance Microphone Preamplifier IC FEATURES Excellent noise performance through the entire gain range Exceptionally low THD+N over the full audio bandwidth Low power

More information

Section 3. Sensor to ADC Design Example

Section 3. Sensor to ADC Design Example Section 3 Sensor to ADC Design Example 3-1 This section describes the design of a sensor to ADC system. The sensor measures temperature, and the measurement is interfaced into an ADC selected by the systems

More information

Absolute Maximum Ratings

Absolute Maximum Ratings RC15 Voltage-to-Frequency Converters www.fairchildsemi.com Features Single supply operation Pulse output DTL/TTL/CMOS compatible Programmable scale factor (K) High noise rejection Inherent monotonicity

More information

PowerAmp Design. PowerAmp Design PAD135 COMPACT HIGH VOLATGE OP AMP

PowerAmp Design. PowerAmp Design PAD135 COMPACT HIGH VOLATGE OP AMP PowerAmp Design COMPACT HIGH VOLTAGE OP AMP Rev G KEY FEATURES LOW COST SMALL SIZE 40mm SQUARE HIGH VOLTAGE 200 VOLTS HIGH OUTPUT CURRENT 10A PEAK 40 WATT DISSIPATION CAPABILITY 200V/µS SLEW RATE APPLICATIONS

More information

5.1 Channel Volume Control

5.1 Channel Volume Control THAT Corporation Design Note 5. Channel Volume Control The circuits within this application note feature THAT8x to provide the essential function of voltage-controlled amplifier (VCA). Since writing this

More information

Electronics. Discrete assembly of an operational amplifier as a transistor circuit. LD Physics Leaflets P4.2.1.1

Electronics. Discrete assembly of an operational amplifier as a transistor circuit. LD Physics Leaflets P4.2.1.1 Electronics Operational Amplifier Internal design of an operational amplifier LD Physics Leaflets Discrete assembly of an operational amplifier as a transistor circuit P4.2.1.1 Objects of the experiment

More information

The output signal may be of the same form as the input signal, i.e. V in produces V out

The output signal may be of the same form as the input signal, i.e. V in produces V out What is an amplifier? Operational Amplifiers A device that takes an input (current, voltage, etc.) and produces a correlated output Input Signal Output Signal Usually the output is a multiple of the input

More information

Generating Common Waveforms Using the LM555, Operational Amplifiers, and Transistors

Generating Common Waveforms Using the LM555, Operational Amplifiers, and Transistors Generating Common Waveforms Using the LM555, Operational Amplifiers, and Transistors Kenneth Young November 16, 2012 I. Abstract The generation of precise waveforms may be needed within any circuit design.

More information

EXPERIMENT 1.2 CHARACTERIZATION OF OP-AMP

EXPERIMENT 1.2 CHARACTERIZATION OF OP-AMP 1.17 EXPERIMENT 1.2 CHARACTERIZATION OF OPAMP 1.2.1 OBJECTIVE 1. To sketch and briefly explain an operational amplifier circuit symbol and identify all terminals 2. To list the amplifier stages in a typical

More information

FIGURE 2. FIGURE 3. FIGURE 4. 2

FIGURE 2. FIGURE 3. FIGURE 4.  2 Applications of the LM3524 Pulse-Width-Modulator The LM3524 Regulating Pulse-Width-Modulator is commonly used as the control element in switching regulator power supplies. This is in keeping with its intended

More information

Inrush Current. Although the concepts stated are universal, this application note was written specifically for Interpoint products.

Inrush Current. Although the concepts stated are universal, this application note was written specifically for Interpoint products. INTERPOINT Although the concepts stated are universal, this application note was written specifically for Interpoint products. In today s applications, high surge currents coming from the dc bus are a

More information

TRANSISTOR AMPLIFIERS AET 8. First Transistor developed at Bell Labs on December 16, 1947

TRANSISTOR AMPLIFIERS AET 8. First Transistor developed at Bell Labs on December 16, 1947 AET 8 First Transistor developed at Bell Labs on December 16, 1947 Objective 1a Identify Bipolar Transistor Amplifier Operating Principles Overview (1) Dynamic Operation (2) Configurations (3) Common Emitter

More information

Building the AMP Amplifier

Building the AMP Amplifier Building the AMP Amplifier Introduction For about 80 years it has been possible to amplify voltage differences and to increase the associated power, first with vacuum tubes using electrons from a hot filament;

More information

# 2. Selecting and Using Thermistors for Temperature Control

# 2. Selecting and Using Thermistors for Temperature Control # 2 Selecting and Using Thermistors for Temperature Control Selecting and Using Thermistors for Temperature Control Thermally sensitive resistors (thermistors) are used widely in laser diode and detector

More information

Measuring Temperature withthermistors a Tutorial David Potter

Measuring Temperature withthermistors a Tutorial David Potter NATIONAL INSTRUMENTS The Software is the Instrument Application Note 065 Measuring Temperature withthermistors a Tutorial David Potter Introduction Thermistors are thermally sensitive resistors used in

More information

PACKAGE OUTLINE DALLAS DS2434 DS2434 GND. PR 35 PACKAGE See Mech. Drawings Section

PACKAGE OUTLINE DALLAS DS2434 DS2434 GND. PR 35 PACKAGE See Mech. Drawings Section PRELIMINARY DS2434 Battery Identification Chip FEATURES Provides unique ID number to battery packs PACKAGE OUTLINE Eliminates thermistors by sensing battery temperature on chip DALLAS DS2434 1 2 3 256

More information

LM386 Low Voltage Audio Power Amplifier

LM386 Low Voltage Audio Power Amplifier Low Voltage Audio Power Amplifier General Description The LM386 is a power amplifier designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count

More information

Designing Gain and Offset in Thirty Seconds

Designing Gain and Offset in Thirty Seconds Application Report SLOA097 February 2002 Designing Gain and Offset in Thirty Seconds Bruce Carter High Performance Linear ABSTRACT This document discusses how to design an operational amplifier (op amp)

More information

MAS.836 HOW TO BIAS AN OP-AMP

MAS.836 HOW TO BIAS AN OP-AMP MAS.836 HOW TO BIAS AN OP-AMP Op-Amp Circuits: Bias, in an electronic circuit, describes the steady state operating characteristics with no signal being applied. In an op-amp circuit, the operating characteristic

More information

LAB 7 MOSFET CHARACTERISTICS AND APPLICATIONS

LAB 7 MOSFET CHARACTERISTICS AND APPLICATIONS LAB 7 MOSFET CHARACTERISTICS AND APPLICATIONS Objective In this experiment you will study the i-v characteristics of an MOS transistor. You will use the MOSFET as a variable resistor and as a switch. BACKGROUND

More information

JFET Basics. by Kenneth A. Kuhn Nov. 3, 2001, rev. Oct. 30, Introduction

JFET Basics. by Kenneth A. Kuhn Nov. 3, 2001, rev. Oct. 30, Introduction by Kenneth A. Kuhn Nov. 3, 2001, rev. Oct. 30, 2008 Introduction A junction field-effect transistor (JFET) consists of a semiconducting channel whose conductance is controlled by an electric field. The

More information

NTE923 & NTE923D Integrated Circuit Precision Voltage Regulator

NTE923 & NTE923D Integrated Circuit Precision Voltage Regulator NTE923 & NTE923D Integrated Circuit Precision Voltage Regulator Description: The NTE923 and NTE923D are voltage regulators designed primarily for series regulator applications. By themselves, these devices

More information

AN105. Introduction: The Nature of VCRs. Resistance Properties of FETs

AN105. Introduction: The Nature of VCRs. Resistance Properties of FETs Introduction: The Nature of s A voltage-controlled resistor () may be defined as a three-terminal variable resistor where the resistance value between two of the terminals is controlled by a voltage potential

More information

AP2428.01. A/D Converter. Analog Aspects. C500 and C166 Microcontroller Families. Microcontrollers. Application Note, V 1.

AP2428.01. A/D Converter. Analog Aspects. C500 and C166 Microcontroller Families. Microcontrollers. Application Note, V 1. Application Note, V 1.0, May 2001 AP2428.01 A/D Converter C500 and C166 Microcontroller Families Analog Aspects Microcontrollers Never stop thinking. A/D Converter Revision History: 2001-05 V1.0 Previous

More information

NTE2053 Integrated Circuit 8 Bit MPU Compatible A/D Converter

NTE2053 Integrated Circuit 8 Bit MPU Compatible A/D Converter NTE2053 Integrated Circuit 8 Bit MPU Compatible A/D Converter Description: The NTE2053 is a CMOS 8 bit successive approximation Analog to Digital converter in a 20 Lead DIP type package which uses a differential

More information

Chapter 12: The Operational Amplifier

Chapter 12: The Operational Amplifier Chapter 12: The Operational Amplifier 12.1: Introduction to Operational Amplifier (Op-Amp) Operational amplifiers (op-amps) are very high gain dc coupled amplifiers with differential inputs; they are used

More information

Isolated AC Sine Wave Input 3B42 / 3B43 / 3B44 FEATURES APPLICATIONS PRODUCT OVERVIEW FUNCTIONAL BLOCK DIAGRAM

Isolated AC Sine Wave Input 3B42 / 3B43 / 3B44 FEATURES APPLICATIONS PRODUCT OVERVIEW FUNCTIONAL BLOCK DIAGRAM Isolated AC Sine Wave Input 3B42 / 3B43 / 3B44 FEATURES AC averaging technique used to rectify, amplify, and filter 50 Hz to 400 Hz sine-wave signals. Accepts inputs of between 20 mv to 550 V rms to give

More information

DS1807. Addressable Dual Audio Taper Potentiometer FEATURES PIN ASSIGNMENT

DS1807. Addressable Dual Audio Taper Potentiometer FEATURES PIN ASSIGNMENT DS1807 Addressable Dual Audio Taper Potentiometer FEATURES Operates from 3V or 5V Power Supplies PIN ASSIGNMENT GND 1 14 V CC Ultra low power consumption A2 2 13 SCL Two digitally controlled, 65 position

More information

Analog Signal Conditioning

Analog Signal Conditioning Analog Signal Conditioning Analog and Digital Electronics Electronics Digital Electronics Analog Electronics 2 Analog Electronics Analog Electronics Operational Amplifiers Transistors TRIAC 741 LF351 TL084

More information

Use and Application of Output Limiting Amplifiers (HFA1115, HFA1130, HFA1135)

Use and Application of Output Limiting Amplifiers (HFA1115, HFA1130, HFA1135) Use and Application of Output Limiting Amplifiers (HFA111, HFA110, HFA11) Application Note November 1996 AN96 Introduction Amplifiers with internal voltage clamps, also known as limiting amplifiers, have

More information

BIASING OF CONSTANT CURRENT MMIC AMPLIFIERS (e.g., ERA SERIES) (AN-60-010)

BIASING OF CONSTANT CURRENT MMIC AMPLIFIERS (e.g., ERA SERIES) (AN-60-010) BIASING OF CONSTANT CURRENT MMIC AMPLIFIERS (e.g., ERA SERIES) (AN-60-010) Introduction The Mini-Circuits family of microwave monolithic integrated circuit (MMIC) Darlington amplifiers offers the RF designer

More information

Analog Electronics II Laboratory Exercise 2 Cascade amplifier with BJT

Analog Electronics II Laboratory Exercise 2 Cascade amplifier with BJT Analog Electronics II Laboratory Exercise 2 Cascade amplifier with BJT Aim of the exercise The aim of this laboratory exercise is to become familiar with the operation of the cascade connection of the

More information

AP331A XX G - 7. Lead Free G : Green. Packaging (Note 2)

AP331A XX G - 7. Lead Free G : Green. Packaging (Note 2) Features General Description Wide supply Voltage range: 2.0V to 36V Single or dual supplies: ±1.0V to ±18V Very low supply current drain (0.4mA) independent of supply voltage Low input biasing current:

More information

Programmable-Gain Transimpedance Amplifiers Maximize Dynamic Range in Spectroscopy Systems

Programmable-Gain Transimpedance Amplifiers Maximize Dynamic Range in Spectroscopy Systems Programmable-Gain Transimpedance Amplifiers Maximize Dynamic Range in Spectroscopy Systems PHOTODIODE VOLTAGE SHORT-CIRCUIT PHOTODIODE SHORT- CIRCUIT VOLTAGE 0mV DARK ark By Luis Orozco Introduction Precision

More information

Chapter 20 DAC, DAC AND ANALOG- DIGITAL MIX INTERFACES

Chapter 20 DAC, DAC AND ANALOG- DIGITAL MIX INTERFACES Chapter 20 DAC, DAC AND ANALOG- DIGITAL MIX INTERFACES Lesson 2 DIGITAL TO ANALOG CONVERTER (DAC or D/A) Ch20L2-"Digital Principles and Design", Raj Kamal, Pearson Education, 2006 2 Outline DAC DAC Circuit

More information

LM138 LM338 5-Amp Adjustable Regulators

LM138 LM338 5-Amp Adjustable Regulators LM138 LM338 5-Amp Adjustable Regulators General Description The LM138 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 5A over a 1 2V to 32V output range

More information

LM56 Dual Output Low Power Thermostat

LM56 Dual Output Low Power Thermostat Dual Output Low Power Thermostat General Description The LM56 is a precision low power thermostat. Two stable temperature trip points (V T1 and V T2 ) are generated by dividing down the LM56 1.250V bandgap

More information

EXERCISES in ELECTRONICS and SEMICONDUCTOR ENGINEERING

EXERCISES in ELECTRONICS and SEMICONDUCTOR ENGINEERING Department of Electrical Drives and Power Electronics EXERCISES in ELECTRONICS and SEMICONDUCTOR ENGINEERING Valery Vodovozov and Zoja Raud http://learnelectronics.narod.ru Tallinn 2012 2 Contents Introduction...

More information

AP-1 Application Note on Remote Control of UltraVolt HVPS

AP-1 Application Note on Remote Control of UltraVolt HVPS Basics Of UltraVolt HVPS Output Voltage Control Application Note on Remote Control of UltraVolt HVPS By varying the voltage at the Remote Adjust Input terminal (pin 6) between 0 and +5V, the UV highvoltage

More information

BJT Circuit Analysis

BJT Circuit Analysis BJT Circuit Analysis Assuming that the transistor is in the active region, solve for the voltages and currents --- why this assumption? In general, the problem requires solution of a set of nonlinear equations:

More information

AN1982 Applying the oscillator of the SA602 in low-power mixer applications

AN1982 Applying the oscillator of the SA602 in low-power mixer applications RF COMMUNICATIONS PRODUCTS Applying the oscillator of the SA02 in low-power Donald Anderson 99 Oct 23 Philips Semiconductors Applying the oscillator of the SA02 in low-power Author: Donald Anderson INTRODUCTION

More information

Theory of Operation. Figure 1 illustrates a fan motor circuit used in an automobile application. The TPIC2101. 27.4 kω AREF.

Theory of Operation. Figure 1 illustrates a fan motor circuit used in an automobile application. The TPIC2101. 27.4 kω AREF. In many applications, a key design goal is to minimize variations in power delivered to a load as the supply voltage varies. This application brief describes a simple DC brush motor control circuit using

More information

INTEGRATED CIRCUITS DATA SHEET. TDA8340 TDA8341 Television IF amplifier and demodulator. Product specification File under Integrated Circuits, IC02

INTEGRATED CIRCUITS DATA SHEET. TDA8340 TDA8341 Television IF amplifier and demodulator. Product specification File under Integrated Circuits, IC02 INTEGRATED CIRCUITS DATA SHEET Television IF amplifier and demodulator File under Integrated Circuits, IC02 November 1987 DESCRIPTION The ;Q and ;Q are integrated IF amplifier and demodulator circuits

More information

LF412 Low Offset Low Drift Dual JFET Input Operational Amplifier

LF412 Low Offset Low Drift Dual JFET Input Operational Amplifier LF412 Low Offset Low Drift Dual JFET Input Operational Amplifier General Description These devices are low cost high speed JFET input operational amplifiers with very low input offset voltage and guaranteed

More information

LM139/LM239/LM339/LM2901/LM3302 Low Power Low Offset Voltage Quad Comparators

LM139/LM239/LM339/LM2901/LM3302 Low Power Low Offset Voltage Quad Comparators Low Power Low Offset Voltage Quad Comparators General Description The LM139 series consists of four independent precision voltage comparators with an offset voltage specification as low as 2 mv max for

More information

R EXT THERMISTOR. Maxim Integrated Products 1

R EXT THERMISTOR. Maxim Integrated Products 1 19-2219; Rev 0; 2/02 Thermistor-to-Digital Converter General Description The converts an external thermistor s temperature-dependent resistance directly into digital form. The thermistor and an external

More information

Welcome to this presentation on Driving LEDs Resistors and Linear Drivers, part of OSRAM Opto Semiconductors LED Fundamentals series.

Welcome to this presentation on Driving LEDs Resistors and Linear Drivers, part of OSRAM Opto Semiconductors LED Fundamentals series. Welcome to this presentation on Driving LEDs Resistors and Linear Drivers, part of OSRAM Opto Semiconductors LED Fundamentals series. In this presentation we will look at: - Simple resistor based current

More information

Ametek, Inc. Rotron Technical Products Division. 627 Lake Street Kent, Ohio User's Guide. Number Revision E

Ametek, Inc. Rotron Technical Products Division. 627 Lake Street Kent, Ohio User's Guide. Number Revision E Ametek, Rotron Technical Products Division 627 Lake Street Kent, Ohio 44240 User's Guide 120 Volt, 800 Watt and 240 Volt, 1200 Watt Brushless Motor Drive Electronics 5.7" (145 mm) and 7.2" (183 mm) Windjammer

More information

Programmable Single-/Dual-/Triple- Tone Gong SAE 800

Programmable Single-/Dual-/Triple- Tone Gong SAE 800 Programmable Single-/Dual-/Triple- Tone Gong Preliminary Data SAE 800 Bipolar IC Features Supply voltage range 2.8 V to 18 V Few external components (no electrolytic capacitor) 1 tone, 2 tones, 3 tones

More information

Dual High Speed, Implanted BiFET Op Amp AD644

Dual High Speed, Implanted BiFET Op Amp AD644 a FEATURES Matched Offset Voltage Matched Offset Voltage Over Temperature Matched Bias Currents Crosstalk 124 db at 1 khz Low Bias Current: 35 pa max Warmed Up Low Offset Voltage: 500 V max Low Input Voltage

More information

SINGLE-SUPPLY OPERATION OF OPERATIONAL AMPLIFIERS

SINGLE-SUPPLY OPERATION OF OPERATIONAL AMPLIFIERS SINGLE-SUPPLY OPERATION OF OPERATIONAL AMPLIFIERS One of the most common applications questions on operational amplifiers concerns operation from a single supply voltage. Can the model OPAxyz be operated

More information

TDA2040. 20W Hi-Fi AUDIO POWER AMPLIFIER

TDA2040. 20W Hi-Fi AUDIO POWER AMPLIFIER 20W Hi-Fi AUDIO POWER AMPLIFIER DESCRIPTION The TDA2040 is a monolithic integrated circuit in Pentawatt package, intended for use as an audio class AB amplifier. Typically it provides 22W output power

More information

Reading: HH Sections 4.11 4.13, 4.19 4.20 (pgs. 189-212, 222 224)

Reading: HH Sections 4.11 4.13, 4.19 4.20 (pgs. 189-212, 222 224) 6 OP AMPS II 6 Op Amps II In the previous lab, you explored several applications of op amps. In this exercise, you will look at some of their limitations. You will also examine the op amp integrator and

More information

SELF-OSCILLATING HALF-BRIDGE DRIVER

SELF-OSCILLATING HALF-BRIDGE DRIVER Features Floating channel designed for bootstrap operation Fully operational to +600V olerant to negative transient voltage dv/dt immune Undervoltage lockout Programmable oscillator frequency 1 f = 1.4

More information

The George Washington University School of Engineering and Applied Science Department of Electrical and Computer Engineering

The George Washington University School of Engineering and Applied Science Department of Electrical and Computer Engineering The George Washington University School of Engineering and Applied Science Department of Electrical and Computer Engineering Final Design Report Dual Channel Stereo Amplifier By: Kristen Gunia Prepared

More information

MM74HC4046 CMOS Phase Lock Loop

MM74HC4046 CMOS Phase Lock Loop CMOS Phase Lock Loop General Description The MM74HC4046 is a low power phase lock loop utilizing advanced silicon-gate CMOS technology to obtain high frequency operation both in the phase comparator and

More information

DIGITAL-TO-ANALOGUE AND ANALOGUE-TO-DIGITAL CONVERSION

DIGITAL-TO-ANALOGUE AND ANALOGUE-TO-DIGITAL CONVERSION DIGITAL-TO-ANALOGUE AND ANALOGUE-TO-DIGITAL CONVERSION Introduction The outputs from sensors and communications receivers are analogue signals that have continuously varying amplitudes. In many systems

More information

Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz

Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz Author: Don LaFontaine Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz Abstract Making accurate voltage and current noise measurements on op amps in

More information

Lab 7: Operational Amplifiers Part I

Lab 7: Operational Amplifiers Part I Lab 7: Operational Amplifiers Part I Objectives The objective of this lab is to study operational amplifier (op amp) and its applications. We will be simulating and building some basic op amp circuits,

More information

Analog Devices Welcomes Hittite Microwave Corporation NO CONTENT ON THE ATTACHED DOCUMENT HAS CHANGED

Analog Devices Welcomes Hittite Microwave Corporation NO CONTENT ON THE ATTACHED DOCUMENT HAS CHANGED Analog Devices Welcomes Hittite Microwave Corporation NO CONTENT ON THE ATTACHED DOCUMENT HAS CHANGED www.analog.com www.hittite.com THIS PAGE INTENTIONALLY LEFT BLANK v.113 Frequency Divider Operation

More information

LM35 Precision Centigrade Temperature Sensors

LM35 Precision Centigrade Temperature Sensors Precision Centigrade Temperature Sensors General Description Typical Applications The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to

More information

Isolation of Battery Chargers Integrated Into Printed Circuit Boards

Isolation of Battery Chargers Integrated Into Printed Circuit Boards LLNL-TR-646864 Isolation of Battery Chargers Integrated Into Printed Circuit Boards J. S. Sullivan November 26, 2013 Disclaimer This document was prepared as an account of work sponsored by an agency of

More information

Low Profile, Low Cost, Fully Integrated Monolithic Microwave Amplifiers

Low Profile, Low Cost, Fully Integrated Monolithic Microwave Amplifiers (AN-60-016) Low Profile, Low Cost, Fully Integrated Monolithic Microwave Amplifiers Engineering Department Mini-Circuits, Brooklyn, NY 11235 Introduction Monolithic microwave amplifiers are widely used

More information

CMOS Sample-and-Hold Circuits

CMOS Sample-and-Hold Circuits CMOS Sample-and-Hold Circuits ECE 1352 Reading Assignment By: Joyce Cheuk Wai Wong November 12, 2001 Department of Electrical and Computer Engineering University of Toronto 1. Introduction Sample-and-hold

More information