0.1GHz to 2.5GHz, 75dB Logarithmic Detector/Controller

Transcription

1 9-99; Rev ; /.GHz to.5ghz, 75dB Logarithmic General Description The MAX5 complete multistage logarithmic amplifier is designed to accurately convert radio-frequency (RF) signal power in the.ghz to.5ghz frequency range to an equivalent DC voltage. The outstanding dynamic range and precision over temperature of this log amplifier make it particularly useful for a variety of base station and other wireless applications, including automatic gain control (AGC), transmitter power measurements, and received signal strength indication (RSSI) for terminal devices. The MAX5 can also be operated in a controller mode where it measures, compares, and controls the output power of a variable-gain amplifier as part of a fully integrated AGC loop. This logarithmic amplifier provides much wider measurement range and superior accuracy compared to controllers based on diode detectors, while achieving excellent temperature stability over the full -4 C to +5 C operating range. Applications AGC Measurement and Control RF Transmitter Power Measurement RSSI Measurements Cellular Base Station, WLAN, Microwave Link, Radar, and other Military Applications Features Complete RF.GHz to.5ghz Frequency Range Exceptional Accuracy Over Temperature High Dynamic Range.7V to 5.5V Supply Voltage Range* Scaling Stable Over Supply and Temperature Variations Controller Mode with Error Output Shutdown Mode with Typically µa of Supply Current Available in -Pin µmax Package *See Power-Supply Connections section. Ordering Information PART TEMP RANGE PIN-PACKAGE MAX5EUA-T -4 C to +5 C µmax Functional Diagram MAX5, 4 POWER DETECTORS INHI Σ Σ Σ INLO 5Ω 7dB 7dB 7dB kω 7 SET PWDN 5 OFFSET AND COMMON- MODE AMP kω MAX5 Pin Configuration appears at end of data sheet. 6 GND Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 .GHz to.5ghz, 75dB Logarithmic MAX5 ABSOLUTE MAXIMUM RATINGS (Pins,, 4) to GND...-.V to +5.5V SET, PWDN to GND...-.V to ( +.V) Input Power Differential INHI, INLO...+dBm Input Power Single Ended (INHI or INLO grounded)...+9dbm Continuous Power Dissipation (T A = +7 C) -Pin µmax (derate 4.5mW/ C above +7 C)...6mW Operating Temperature Range...-4 C to +5 C Junction Temperature...+5 C Storage Temperature Range C to +5 C Lead Temperature (soldering, s)...+ C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (MAX5 Typical Application Circuit (Figure ), V S = +.V, f RF = MHz to 5MHz, R = Ω, R4 = Ω, R L = kω, T A = -4 C to +5 C, unless otherwise noted. Typical values are at T A = +5 C, unless otherwise noted.) (Note ) POWER SUPPLY PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V S R4 = 75Ω ±%, PWDN must be connected to GND R4 = Ω.7.6 V Supply Current I CC T A = +5 C, V S = 5.5V, R4 = 75Ω 7. T A = +5 C 7..5 ma Supply Current Variation with Temp I CC T A = -4 C to +5 C.5 ma/ C Shutdown Current I CC V PWDN = µa CONTROLLER REFERENCE (SET) SET Input Voltage Range.5 to. V SET Input Impedance 4 kω DETECTOR PUT () Source Current 4 ma Sink Current 45 µa Minimum Output Voltage V (MIN).5 V Maximum Output Voltage V (MAX). V

3 .GHz to.5ghz, 75dB Logarithmic AC ELECTRICAL CHARACTERISTICS (MAX5 Typical Application Circuit (Figure ), V S = +.V, f RF = MHz to 5MHz, R = Ω, R4 = Ω, R L = kω, T A = -4 C to +5 C, unless otherwise noted. Typical values are at T A = +5 C, unless otherwise noted.) (Note ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS RF Input Frequency Range f RF. to.5 GHz Return Loss S -5 db Large-Signal Response Time RSSI MODE.GHz P IN = no signal to dbm, ±.5dB settling accuracy 5 ns RF Input Power Range (Note ) -65 to +5 dbm ±db Dynamic Range T A = -4 C to +5 C (Note ) 7 db Range Center - dbm Temp Sensitivity when T A > +5 C T A = +5 C to +5 C, P IN = -5dBm +. db/ C MAX5 Temp Sensitivity when T A < +5 C T A = -4 C to +5 C, P IN = -5dBm -.54 db/ C Slope (Note 4) 9 mv/db Typical Slope Variation T A = -4 C to +5 C -4 µv/ C Intercept (Note 5) - dbm Typical Intercept Variation T A = -4 C to +5 C. dbm/ C RSSI MODE.9GHz RF Input Power Range (Note ) -65 to +5 dbm ±db Dynamic Range T A = -4 C to +5 C (Note ) 7 db Range Center - dbm Temp Sensitivity when T A > +5 C Temp Sensitivity when T A < +5 C T A = +5 C to +5 C, P IN = -5dBm T A = -4 C to +5 C, P IN = -5dBm ±. db/ C -.54 db/ C Slope (Note 4). mv/db Typical Slope Variation T A = -4 C to +5 C -4 µv/ C Intercept (Note 5) -97 dbm Typical Intercept Variation T A = -4 C to +5 C. dbm/ C RSSI MODE.9GHz RF Input Power Range (Note ) -55 to +5 dbm ±db Dynamic Range T A = -4 C to +5 C (Note ) 6 db Range Center -5 dbm Temp Sensitivity when T A > +5 C Temp Sensitivity when T A < +5 C T A = +5 C to +5 C, P IN = -5dBm T A = -4 C to +5 C, P IN = -5dBm ±. db/ C -. db/ C Slope (Note 4) mv/db Typical Slope Variation T A = -4 C to +5 C -4. µv/ C

4 .GHz to.5ghz, 75dB Logarithmic MAX5 AC ELECTRICAL CHARACTERISTICS (continued) (MAX5 Typical Application Circuit (Figure ), V S = +.V, f RF = MHz to 5MHz, R = Ω, R4 = Ω, R L = kω, T A = -4 C to +5 C, unless otherwise noted. Typical values are at T A = +5 C, unless otherwise noted.) (Note ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Intercept (Note 5) - dbm Typical Intercept Variation T A = -4 C to +5 C. dbm/ C RSSI MODE.5GHz RF Input Power Range (Note ) -45 to -5 dbm ±db Dynamic Range T A = -4 C to +5 C (Note ) 4 db Range Center -5 dbm Temp Sensitivity when T A > +5 C T A = +5 C to +5 C, P IN = -5dBm -. db/ C Temp Sensitivity when T A < +5 C T A = -4 C to +5 C, P IN = -5dBm -. db/ C Slope (Note 4) 6. mv/db Typical Slope Variation T A = -4 C to +5 C - µv/ C Intercept (Note 5) - dbm Typical Intercept Variation T A = -4 C to +5 C. dbm/ C Note : The MAX5 is % production tested at T A = +5 C and is guaranteed by design for T A = -4 C to +5 C, as specified. Note : Typical minimum and maximum range of the detector at the stated frequency. Note : Dynamic range refers to the range over which the error remains within the stated bounds. The error is calculated at -4 C and +5 C, relative to the curve at +5 C. Note 4: The slope is the variation of the output voltage per change in input power. It is calculated by fitting a root-mean-square (RMS) straight line to the data indicated by RF input power range. Note 5: The intercept is an extrapolated value that corresponds to the output power for which the output voltage is zero. It is calculated by fitting an RMS straight line to the data. 4

5 .GHz to.5ghz, 75dB Logarithmic Typical Operating Characteristics (MAX5 Typical Application Circuit (Figure ), V S = =.V, P IN = -dbm, f IN = MHz, R = Ω, R4 = Ω, R L = kω, V PWDN = V, T A = +5 C, unless otherwise noted.) PUT VOLTAGE (V) f IN =.GHz PUT VOLTAGE. T A = +5 C.6 T A = -4 C MAX5 toc f IN =.GHz NORMALIZED TO DATA AT +5 C T A = +5 C T A = -4 C MAX5 toc - - =.7V f IN =.GHz, NORMALIZED TO DATA AT +5 C =.6V =.V =.V MAX5 toc MAX5 - - f IN =.GHz, T A = -4 C NORMALIZED TO DATA AT +5 C =.V =.7V =.V =.6V MAX5 toc4 PUT VOLTAGE (V) f IN =.9GHz PUT VOLTAGE. T A = +5 C.6 T A = -4 C MAX5 toc5 - - f IN =.9GHz NORMALIZED TO DATA AT +5 C T A = +5 C T A = -4 C MAX5 toc6 - =.7V f IN =.9GHz, NORMALIZED TO DATA AT +5 C =.V =.6V =.V MAX5 toc7 - f IN =.9GHz, T A = -4 C NORMALIZED TO DATA AT +5 C =.V =.V =.7V MAX5 toc PUT VOLTAGE (V) f IN =.9GHz PUT VOLTAGE MAX5 toc =.6V T A = +5 C T A = -4 C

6 .GHz to.5ghz, 75dB Logarithmic MAX5 Typical Operating Characteristics (continued) (MAX5 Typical Application Circuit (Figure ), V S = =.V, P IN = -dbm, f IN = MHz, R = Ω, R4 = Ω, R L = kω, V PWDN = V, T A = +5 C, unless otherwise noted.) - - f IN =.9GHz NORMALIZED TO DATA AT +5 C T A = +5 C T A = -4 C MAX5 toc - - f IN =.9GHz, NORMALIZED TO DATA AT +5 C =.7V =.6V =.V =.V MAX5 toc - - f IN =.9GHz, T A = -4 C NORMALIZED TO DATA AT +5 C =.V =.7V =.V =.6V MAX5 toc f IN =.5GHz PUT VOLTAGE MAX5 toc f IN =.5GHz NORMALIZED TO DATA AT +5 C MAX5 toc4 f IN =.5GHz, NORMALIZED TO DATA AT +5 C MAX5 toc5 PUT VOLTAGE (V)...6 T A = +5 C T A = -4 C T A = +5 C - T A = -4 C =.V =.6V - =.7V VCC =.V f IN =.5GHz, T A = -4 C NORMALIZED TO DATA AT +5 C =.V =.7V =.V =.6V MAX5 toc6 RF INPUT VOLTAGE, PUT VOLTAGE (V) f IN = MHz RF PULSE RESPONSE V RFIN (AC-COUPLED) MAX5 toc TIME (5ns/div) 6

7 .GHz to.5ghz, 75dB Logarithmic Typical Operating Characteristics (continued) (MAX5 Typical Application Circuit (Figure ), V S = =.V, P IN = -dbm, f IN = MHz, R = Ω, R4 = Ω, R L = kω, V PWDN = V, T A = +5 C, unless otherwise noted.) MAGNITUDE (db) S MAGNITUDE =.V,.6V =.7V,.V MAX5 toc MAGNITUDE (db) T A = -4 C T A = +5 C S MAGNITUDE MAX5 toc9 MAX FREQUENCY (GHz) FREQUENCY (GHz) Pin Description PIN NAME DESCRIPTION, 4 Supply Voltage. Bypass with capacitors as specified in the application drawing. Place capacitors as close to the pin as possible (see Power-Supply Connections section)., INHI, INLO Differential RF Inputs 5 PWDN Power-Down Input. Drive PWDN with a logic high to power down the IC. PWDN must be connected to GND for V S between 4.75V and 5.5V with R4 = 75Ω 6 GND Ground. Connect to the printed circuit (PC) board ground plane. 7 SET Set-Point Input. To operate in detector mode, connect SET to. To operate in controller mode, connect a precision voltage source to control the power level of a power amplifier. Detector Output. In detector mode, this output provides a voltage proportional to the log of the input power. In controller mode, this output is connected to a power-control input on a power amplifier (PA). 7

8 .GHz to.5ghz, 75dB Logarithmic MAX5 Detailed Description The MAX5 is a successive detection logarithmic amplifier designed for use in RF power measurement and AGC applications with a.ghz to.5ghz frequency range from a single.7v to.6v power supply. It is pin compatible with other leading logarithmic amplifiers. The MAX5 provides for improved performance with a high 75dB dynamic range at MHz, and exceptional accuracy over the extended temperature range and supply voltage range. RF Input The MAX5 differential RF input (INHI, INLO) allows for broadband signals between MHz and.5ghz. For single-ended signals, AC-couple INLO to ground. The RF inputs are internally biased and need to be ACcoupled using 6pF capacitors as shown in Figure and Figure. An internal 5Ω resistor between INHI and INLO provides a good 5MHz to.ghz match. SET Input The SET input is used for loop control when in controller mode or to set the slope of the output signal (mv/db) when in detector mode. The internal input structure of SET is two series kω resistors connected to ground. The center node of the resistors is fed to the negative input of the internal output op amp. Power-Supply Connections The MAX5 requires power-supply bypass capacitors connected close to each pin. At each pin, connect a.µf capacitor (C4, C6) and a pf capacitor (C, C5) with the pf capacitor being closest to the pin. For power-supply voltages (V S ) between.7v and.6v, set R4 = Ω (see Typical Apllications Circuits). For power-supply voltages (V S ) between 4.75V and 5.5V, set R4 = 75Ω ±% (ppm/ C max) and PWDN must be connected to GND. Power-Down Mode The MAX5 can be powered down by driving PWDN with logic high (logic high = ). In power-down mode, the supply current is reduced to a typical value of µa. For normal operation, drive PWDN with a logic low. It is recommended when using power-down that an RF signal not be applied before the power-down signal is low. Applications Information Detector (RSSI) Mode In detector mode, the MAX5 acts like an RSSI, which provides an output voltage proportional to the input power. This is accomplished by providing a feedback path from to SET (R = Ω; see Figure ). By connecting SET directly to, the op amp gain is set to V/V due to two internal kω feedback resistors. This provides a detector slope of approximately mv/db with a.5v to.v output range. V S R4 C6 RFIN C4 C5 C C C 4 INHI INLO DETECTORS kω MAX5 kω SET 7 GND 6 PWDN 5 Figure. Detector-Mode (RSSI) Typical Application Circuit Table. Suggested Components of Typical Applications Circuits DESIGNATION VALUE TYPE R C, C 6pF 6 ceramic capacitors C, C5 pf 6 ceramic capacitors C4, C6.µF 6 ceramic capacitors R* Ω 6 resistor R4** Ω 6 resistor *RSSI mode only. **V S =.7V to.6v.

9 .GHz to.5ghz, 75dB Logarithmic Controller Mode The MAX5 can also be used as a detector/controller within an AGC loop. Figure depicts one scenario where the MAX5 is employed as the controller for a variable-gain PA. As shown in the figure, the MAX5 monitors the output of the PA through a directional coupler. An internal integrator (Figure ) compares the detected signal with a reference voltage determined by V SET. The integrator, acting like a comparator, increases or decreases the voltage at, according to how closely the detected signal level matches the V SET reference. The MAX5 adjusts the power of the PA to a level determined by the voltage applied to SET. With R = Ω, the controller mode slope is approximately 9mV/dB (RF = MHz). TRANSMITTER POWER AMPLIFIER SET-POINT DAC SET GAIN-CONTROL INPUT kω LOGARITHMIC DETECTOR IN COUPLER MAX5 Layout Considerations As with any RF circuit, the layout of the MAX5 circuit affects the device s performance. Use an abundant number of ground vias to minimize RF coupling. Place the input capacitors (C, C) and the bypass capacitors (C C6) as close to the IC as possible. Connect the bypass capacitors to the ground plane with multiple vias. kω MAX5 Figure. System Diagram for Automatic Gain-Control Loop Pin Configuration V S TOP VIEW R4 C6 RFIN C5 C INHI DETECTORS kω SET 7 V V SET INHI INLO 4 MAX5 µmax SET GND PWDN C4 C C 4 INLO kω MAX5 GND 6 PWDN 5 Chip Information TRANSISTOR COUNT: 57 PROCESS: BiCMOS Figure. Controller-Mode Typical Application Circuit 9

10 .GHz to.5ghz, 75dB Logarithmic MAX5 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to ÿ.5±. D TOP VIEW E H 4X S BOTTOM VIEW DIM A A INCHES MIN MAX BSC A. b c D e E.6 H. L.6 α S.7 BSC MILLIMETERS MIN MAX BSC BSC LUMAXD.EPS A A A e b c L α FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE LINE, L umax/usop APPROVAL DOCUMENT CONTROL NO. REV. -6 J Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.