Agilent: Profile of Oscilloscope Firsts

Transcription

1 Power Measurements & Analysis Solution Marco Vivarelli Sales Scope Specialist Page 1 Agilent: Profile of Oscilloscope Firsts 1960 Sequential sampling oscilloscope 185A 1963 Time-domain reflectometry (TDR) 1415A 1984 Digital variable persistence 54100A 1960: Sequential Sampling Oscilloscope 1984 Oscilloscope with Equivalent Time Sampling 54100A/D 1985 Oscilloscope with a Full Color Display 54110D 1985 Fully integrated logic analyzer and oscilloscope 1631A MS/s digitizing oscilloscope 54200A 1986 Color display 54110D GSa/s Real Time Oscilloscope 54111A 1985: Fully-integrated LA and scope GHz bandwidth 54120A 1987 Time domain transmission measurement 54120A GSa/sec 54111D GHz Sampling Oscilloscope 54124A 1992: 2GHz Real-time Oscilloscope GHz Real Time Oscilloscope 54720A 1996 Mixed Signal Oscilloscope 54645D 1997 Windows-based Oscilloscope Infiniium 1999 Voice-controlled Oscilloscope Infiniium 2002 Modular Probe Head Topology -113x InfiniiMax Probes GSa/s on all 4 channels 54855A GSa/s DSO81304A GHz bandwidth DSO81304A GHz differential probe 1169A 2006 LXI-C Scope Gpts memory 90000A Series 1996: Mixed Signal Oscilloscope 2005: 13GHz Bandwidth with 40GSa/s 2008: 1Gpts memory depth Page 2 1

2 Agilent Portfolio of Oscilloscopes "From 2002 to 2006, Agilent Technologies grew their share of the oscilloscope market nearly twice the rate of Tektronix" High-Bandwidth Sampling High-Performance Lab Infiniium DCA-J Series U1600A Series - Source: Prime Data Sept. 10, 2007 High-Performance Portable General-Purpose Portable Economy Handheld DSO 3000 Series DSO 5000 InfiniiVision Series General-Purpose Lab High-Performance Portable MSO/DSO InfiniiVision 6000 Series MSO/DSO InfiniiVision 7000 Series Infiniium 8000 Series Infiniium Series Page 3 InfiniiVision 7000 Series DSOs and MSOs Biggest screen 12.1 Fastest update rate, with hardware accelerated serial decode Broad insightful apps including new: RS232/UART Segmented Memory Offline Viewing and Analysis Power DSO7032A 350 MHz 2 GSa/s 2 ch. DSO7034A 350 MHz 2 GSa/s 4 ch. MSO7032A 350 MHz 2 GSa/s 2 ch., 2+16 MSO7034A 350 MHz 2 GSa/s 4 ch., 4+16 DSO7052A 500 MHz 4 GSa/s 2 ch. DSO7054A 500 MHz 4 GSa/s 4 ch. MSO7052A 500 MHz 4 GSa/s 2 ch., 2+16 MSO7054A 500 MHz 4 GSa/s 4 ch., 4+16 DSO7104A 1 GHz 4 GSa/s 4 ch., 4+16 MSO7104A 1 GHz 4 GSa/s 4 ch., 4+16 Engineered for the best signal visibility. Page 4 2

3 Infiniium DSO/DSA 90000A Series Superior signal integrity. Deep application analysis. Better insight. Lowest Noise Floor Deepest Memory of 1 Gpts Fastest Hardware Trigger System Fastest Off-Load Speed (remote) Largest Front-Panel Display Fastest measurement speed Fully upgradeable (including bandwidth) Page 5 Scope customers signals being measured Industrial serial(can, SPI, I2C, FlexRay) Switching power supplies Linear power supplies Industrial parallel RF baseband IF < 100 MHz ADCs, DACs bits RF carrier <= 2.5 GHz PWM motor sense/control RF baseband (i.e. DigRF) ADCs, DACs < 10 bits RF baseband IF > 100 MHz ADCs, DACs >= 16 bits USB, Firewire Computer serial PCIE, SATA, FBDIMM Other, please specify RF carrier > 2.5 GHz High Speed Parallel (DDR, PCI-X, etc) Video analog (i.e. NSTC, PAL, VGA Video digital (i.e. DVI, HDMI) Source: Oscilloscope configuration study, Jan 2007 by Agilent DVD Target customers: economy midrange scope users (60MHz 1GHz) Page 6 3

4 What is Your Application? Choose from over 34 oscilloscope applications to meet your testing needs Serial Applications I 2 C, SPI, RS-232/UART and high-speed serial decode with embedded clock recovery Automotive Applications CAN, LIN and Flexray serial triggering and decode Jitter Applications EZJIT jitter analysis, ASA M1 Waveform Viewer General Purpose Applications: Vector Signal Analysis software, FPGA Dynamic Probing, InfiniiScan event identification, Segmented memory, Power measurement Compliance Applications USB 2.0, Ethernet, PCI Express, SATA, HDMI, DisplayPort, DDR1, 2, and 3, communications mask testing High-bandwidth, high-fidelity probing InfiniiMax differential and single-ended active probes maintain scope bandwidth (up to 12GHz), minimize loading on your signal under test and have a flat frequency response across entire probe bandwidth Page 7 Switching power supply customer challenges Reducing cost Improving efficiency & low power loss in converter Increasing power density Increasing reliability Controlling EMI; compliance to EMC regulations All adds up to increased test time! Page 8 4

5 Key Measurements for the Power Supply Designer Provided by the Power Measurements Application Page 9 Losses Due to MOSFET Switching Devices Three types of MOSFET losses: Conduction loss Conduction loss = I 2 R. R in this case is the ON resistance between the drain and source, R ds. R ds should be as low as possible in order to minimize conduction loss. Agilent s Power Measurements Application calculates R ds Switching loss During the transition time (when transiting between ON and OFF states), neither V = 0 nor I = 0, which results in switching loss (P loss ) Page 10 5

6 Power Supply Measurements: Switching Loss Switching losses occur during the switching of V ds and I d (when the switching device is transitioning between ON and OFF states) Page 11 Power Supply Measurements: Conduction Loss The dynamic ON resistance, R ds, is the resistance of the MOSFET in its ON state. This resistance contributes to conduction losses due to the ON state forward voltage drop. Page 12 6

7 Vds Is Switching losses Power Loss Conduction loss Page 13 Measuring Dynamic ON Resistance Traditional Method: Zoom in on Vds Runs the risk of saturating the oscilloscope s front-end amplifiers, which may result in signal distortion and measurement inaccuracy Method embraced by Tektronix and LeCroy More Accurate Method: Use Moving-Average Filtering Capture the waveform on the oscilloscope and use a movingaverage filter to reduce noise and increase measurement resolution. Because this method does reduce signal bandwidth, you do not want to use it to evaluate switching edges. Agilent s Power Measurement Application uses a movingaverage filter for the Dynamic ON resistance test. Page 14 7

8 Page 15 Power Supply Measurements: Noise and Ripple V out Output Voltage with Noise nominal mv rm s mv p-p t Sometimes called ripple or period and random deviations (PARD) Measured in mv rms and mv peak-to-peak For sensitive applications involving low voltage measurements on the DUT, power supply noise could couple into the customer s measurements. The peak-to-peak measurement is important for applications Page where 16 noise spikes can be detrimental to a load such as an RF mixer or radar system. 8

9 Measuring Output Voltage Ripple Ensuring Good Measurement Resolution: Using a 1:1 passive voltage probe provides the best resolution on the small AC ripple signal Software places the oscilloscope in AC coupled mode to maximize the vertical resolution on the ripple Additional low pass or high pass filtering may be defined by the customer in the Test Configuration. It is recommended not to set the low pass filter too close to 50 Hz, because you may want to be able to see if there is any coupling into your output signal from the 50 Hz or 60 Hz line frequency Page 17 Safe Operating Area Defined as the voltage and current conditions over which the device can be expected to operate without self-damage Power device data sheets outline the voltage and current limits of the device Example from ON Semiconductor, device #LTC1871 Page 18 9

10 Modulation Analysis Modulation analysis is a set of measurements specific to the feedback loop (control loop) of the power converter Input to the pulse width modulator (PWM) is the control voltage Output of the PWM is the duty cycle of the converter PWM Control Filtering Output Feedback Block Goal: Wellregulated output voltage Page 19 Page 20 10

11 Inrush Current Measures peak inrush current when the switching power supply is first turned ON Peak inrush current is a result of the impedance of the filter capacitor When the power supply is turned ON, the filter capacitor acts as a short circuit, producing an immediate inrush surge current with a fast rise time Page 21 Current Harmonics Measured against the IEC standard, which provides limits for harmonic current emissions Measures harmonics classes (A, B, C and D) Page 22 11

12 Page 23 Power Quality In a power supply, some AC current may flow into and out of the load without delivering energy this current is called reactive, or harmonic current The reactive current gives rise to an apparent power Power quality is gauged by: Apparent power: The portion of the power flow due to stored energy, which returns to the source in each cycle Real power: The portion of the power flow that, averaged over a complete cycle of the AC waveform, results in a net transfer of energy in one direction Power factor: Ratio of the actual power to apparent power Crest factor: Ratio between the instantaneous peak current and voltage required by the load and the RMS current and voltage. Page 24 12

13 The Agilent Power Measurement Application Page 25 Quick Overview and Timelines Product Description: Application software that measures, analyzes and reports power supply characteristics Introduction Date: February 2008 Compatibility: 6000, 7000, 8000 Series Test Suites: Input Line, Switching Device, Output Line, Inrush Current, Modulation Analysis, Turn on/off Analysis, Transient Analysis Test Modes: Online and Offline 6000 or 7000 USB, LAN or GPIB (6000 only) Power measurement and analysis software Core contribution: Automatic, consistent and fast characterization of SMPS using Agilent oscilloscopes 8000 Page 26 13

14 Power measurements and analysis Line Power Analysis power factor EN61000 precompliance test true power reactive power inrush current etc Power Device Analysis switching loss safe operating area dynamic on resistance di/dt dv/dt Output Analysis output ripple turn on/off time transient response Modulation Analysis pulse width vs time duty cycle vs time period vs time frequency vs time Page 27 Power Measurements Application: Key Features Page 28 Modules Power Device Analysis Input Line Analysis Inrush Current Analysis Output Analysis Turn On/Off Analysis Transient Analysis Modulation Analysis Deskew Report generation Features Switching loss Safe Operating Area (SOA) with SOA mask editing Dynamic On resistance di/dt dv/dt Total Harmonic Distortion Power Factor True Power Apparent Power Crest Factor Current Harmonics PreCompliance test to IEC std. and RTCA DO-160E* Inrush Current Output Voltage Ripple Turn On Time and Turn Off Time Transient Load Response Positive pulse width vs. time plot Duty cycle vs. time plot Period vs. time plot Frequency vs. time plot Deskew (auto prompt before Power Device Analysis, Input Line Analysis tests) DC offset error Report generation (in.html format) 14

15 Deskewing Voltage and Current Probes Deskewing is critical to ensure accurate power (V x I) measurements! U1880A deskew fixture calibrates the time delay between current and voltage probes to ensure accurate power loss measurements Fixture is powered by USB device port on scope or PC Page 29 Voltage and current signals skewed by 5 nsec Deskewed! A PC Summary: application for Power fast characterization Measurements of Application SMPS The software runs on an external PC connected to any InfiniiVision 6000 or 7000 Series (over GPIB, USB and LAN interface) or internally on the Infiniium 8000 Series Report generation provides test reports in customized formats and saves precious development/test time Deskew fixture helps calibrate the time delay between current and voltage probes to ensure accurate power loss measurements A scope, software, differential probe, current probe and deskew fixture form a complete power measurement system Page 30 15

16 Two license options are available: Licensing Oscilloscope-locked license (opt. -001) The application may be installed on as many PC s as desired, but used with only one oscilloscope. Requires instrument ID for licensing. PC-locked license (opt. -002) The application may be installed on only one PC, but used with any compatible oscilloscope. Requires Host ID (available through Help Licensing) for licensing. Page 31 What customer survey said Do you have a need for? 80% 75% 70% 60% 50% 50% 40% 30% 31% 30% 32% 20% 10% 0% High impedance passive probe current probe active probe differential probe high voltage probe Source: Oscilloscope probing survey conducted by Agilent Page 32 16

17 Agilent Oscilloscope Current Probe Lineup 1146A 1147A NEW N2780A Series Low cost 100kHz/100A 0.1V/A or 0.01V/A 9V battery powered 50MHz/15A 1% accuracy 0.1V/A AutoProbe interface provides power 2MHz/10MHz/50MHz/ 100MHz 0.1V/A (50/100MHz), 0.01V/A (2/10MHz) BNC interface requires N2779A power supply Page 33 Selection Guide Product Number Description N2780A N2781A N2782A N2783A N2779A 2MHz/500A current probe 10MHz/150A current probe 50MHz/30A current probe 100MHz/30A current probe 3-channel power supply Page 34 17