RMS Power Detector MAX2203

Transcription

1 9-4982; Rev ; /9 EVALUATION KIT AVAILABLE General Description The MAX22 RMS power detector is designed to operate from 8MHz to 2.GHz. The device is ideal for wideband code-division multiple access (WCDMA), cdma2, and high-speed downlink/uplink packet access. The MAX22 accepts an RF signal at the input and outputs the same voltage regardless of the peak-average of the input signal. The output voltage and input power is linear in db. The device has a -24dBm to +dbm detection range, and every db change in input power gives mv (typ) change in output voltage. The MAX22 operates from a 2.V to 4.2V supply and is specified over the -4 C to +8 C extended temperature range. The device is available in a 6-bump WLP package. Applications WCDMA, cdma2, xevdo High-Speed Downlink Packet Access (HSDPA) High-Speed Uplink Packet Access (HSUPA) RMS Power Detector Features -24dBm to +dbm Power-Detection Range mv/db (typ) Log Detector.dB (typ) RMS Accuracy from WCDMA Modulation Change ±.4dB Detection Error Due to Temperature +2.V to +4.2V Single-Supply Operation Space-Saving 6-Bump WLP Package PART Ordering Information TEMP RANGE PIN- PACKAGE TOP MARK MAX22EWT+T -4 C to +8 C 6 WLP AA +Denotes a lead(pb)-free/rohs-compliant package. T = Tape and reel. Pin Configuration MAX22 Typical Operating Circuit appears at end of data sheet. TOP VIEW (BUMPS ON BOTTOM) + 2 MAX22 A RFIN/ENA GND B GND FILT C V CC OUT cdma2 is a registered trademark of Telecommunications Industry Association. Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim s website at

2 MAX22 ABSOLUTE MAXIMUM RATINGS V CC to GND...-.V to +4.V ENA, OUT, FILT to GND...-.V to +.V RFIN Input Power...+dBm Continuous Power Dissipation (T A = +7 C) 6-Bump WLP (derate 2.9mW/ C above +7 C)...22mW Junction-to-Ambient Thermal Resistance (θ JA ) (Note )...47 C/W Operating Temperature Range...-4 C to +8 C Storage Temperature Range...-6 C to +6 C Junction Temperature...+ C Lead Temperature (soldering, s)...reflow Profile (Note 2) Note : Package thermal resistances were obtained using the method described in JEDEC specifications. For detailed information on package thermal considerations, refer to Note 2: Refer to Application Note 89: Wafer-Level Packaging (WLP) and Its Applications. 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. CAUTION! ESD SENSITIVE DEVICE DC ELECTRICAL CHARACTERISTICS (V CC = 2.V to 4.2V, T A = -4 C to +8 C, V ENA = 2.7V, no RF signal applied. Typical values are at V CC = 2.8V, T A = +2 C, unless otherwise noted.) (Note ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V CC V Supply Current I CC V CC = 2.8V, RF input = -24dBm to +dbm 8 ma Shutdown Supply Current V ENA = V. µa ENA Logic-High Threshold V IH. 2.7 V ENA Logic-Low Threshold V IL.6 V ENA Input Current V ENA =.V 2 µa AC ELECTRICAL CHARACTERISTICS (V CC = 2.8V, T A = -4 C to +8 C, V ENA = 2.7V, f RF = 8MHz to 2GHz, unless otherwise noted. Typical values are at T A = +2 C.) (Note ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS RF Input Frequency 8 2 MHz Maximum Output Voltage RFIN at +dbm...7 V Minimum Output Voltage No RF input power 4 mv Minimum Input Power Level +db input power step results in at least 2mV increase in V OUT (Note 4) -24 dbm Log Slope [(V OUT at +dbm) - (V OUT at -24dBm)]/ mv/db Log Conformance Error with db Step Power-Detector Accuracy Due to Temperature (Notes 4, ) db RF input at -4dBm to dbm, T A = -4 C to +8 C, relative to +2 C ±.4 db Note : Guaranteed by production test at T A = +8 C and 8MHz. Guaranteed by design and characterization at T A = -4 C and T A = +2 C, and over frequency limits. Note 4: Guaranteed by design and characterization. Note : Input power -24dBm to +dbm. Ideal straight line calibrated with input power -2dBm and dbm at T A = +2 C. 2

3 Typical Operating Characteristics (V CC = 2.7V, T A = +2 C, WCDMA uplink DPCCH + DPDCH, log conformance calculation is referenced to a straight line that is calibrated at -2dBm and dbm, unless otherwise noted.) OUTPUT VOLTAGE (V) OUTPUT VOLTAGE vs. INPUT POWER 8MHz 2MHz MAX22 toc RMS ERROR (db) PCS WCDMA + vs. + RMS ERROR (± DEVIATION FROM MIDPOINT) MAX22 toc2 RMS ERROR (db) CELL WCDMA + vs. + RMS ERROR (± DEVIATION FROM MIDPOINT) MAX22 toc MAX P IN (dbm) P IN (dbm) LOG CONFORMANCE WITH db STEP CELLULAR BAND + x STDEV - x STDEV MAX22 toc LOG CONFORMANCE WITH db STEP PCS BAND + x STDEV - x STDEV MAX22 toc LOG CONFORMANCE WITH db STEP CELLULAR BAND + x STDEV - x STDEV MAX22 toc LOG CONFORMANCE WITH db STEP PCS BAND + x STDEV MAX22 toc UNIT CELLULAR ROOM-COLD MAX22 toc8 - x STDEV

4 MAX22 Typical Operating Characteristics (continued) (V CC = 2.7V, T A = +2 C, WCDMA uplink DPCCH + DPDCH, log conformance calculation is referenced to a straight line that is calibrated at -2dBm and dbm, unless otherwise noted.) UNIT PCS ROOM-COLD MAX22 toc UNIT PCS ROOM-HOT MAX22 toc UNIT CELLULAR ROOM-HOT MAX22 toc VOUT (V) OUTPUT VOLTAGE vs. FREQUENCY +dbm dbm -dbm -dbm -dbm -2dBm MAX22 toc2.v/div MAX22 toc INPUT POWER = dbm, 8MHz.V/div MAX22 toc4 INPUT POWER = dbm, 2MHz.4-2dBm FREQUENCY (MHz) V/div 4µs/div.2V/div 4µs/div MAX22 toc MAX22 toc6.v/div.v/div INPUT POWER = -2dBm, 8MHz INPUT POWER = -2dBm, 2MHz mv/div mv/div 4µs/div 4µs/div 4

5 BUMP NAME FUNCTION Pin Description A RFIN/ENA RF Input and Enable Logic Input. See the Typical Operating Circuit. Drive ENA high to turn on the device. Drive ENA low to place it in shutdown mode. A2, B GND Ground. Connect to PCB ground plane. B2 FILT Intermediate Filtering Node. Bypass FILT with a capacitor as close as possible to the device. Power Supply. Connect to either a regulated supply or battery. Bypass V CC with a capacitor as close C V CC as possible to the device. C2 OUT Detector Output. Connect an external lowpass RC filter for filtering. MAX22 Detailed Description The MAX22 RMS power detector is designed to operate from 8MHz to 2.GHz. The device is ideal for WCDMA, cdma2, and high-speed downlink/uplink packet access. The MAX22 accepts an RF signal at the input and outputs the same voltage regardless of the peak-average of the input signal. The output voltage and input power is linear in db. The device has a -24dBm to +dbm detection range, and every db change in input power gives mv (typ) change in output voltage. Table shows the peak to average of the signals used to test the MAX22. Table. Peak-to-Average Ratio (PAR*) of Test Signals PAR AT DIFFERENT PROBABILITY OF COMPLEMENTARY CUMULATIVE MODULATION DISTRIBUTION (db) % %.%.% DPCCH + DPDCH DPCCH + DPDCH IS9 Reverse IS9 Forward Pilot Channel Forward cdma2 Pilot + DCCH *PAR of CW is db.

6 MAX22 Ω COUPLER Ω PA PA 2 COUPLER 2 Ω Ω RMS DETECT BUFFER DETECTOR OUTPUT ENABLE BIAS MAX22 Figure. System Level Connection Applications Information The MAX22 uses external termination when using directional couplers. Figure shows the system level connection of dual-band power detection. The output of the detector is typically connected to an ADC in cdma2 or WCDMA power-control topology. Enable Logic Level The MAX22 features an enable input (ENA) that allows the device to be put into shutdown. For normal operation, drive ENA high. For device shutdown, drive ENA low. The ENA pin is DC biased through a resistor. The value of the resistor is recommended to be greater than kω to avoid loading the RF input signal. There is an internal resistor to GND of approximately kω. If the control source high voltage is greater than 2.8V, calculate and use a resistor value that ensures the ENA pin only sees a maximum of 2.7V, which is within specification. In this manner, the MAX22 can be driven from a control device with a logic-high greater than 2.8V. Layout The MAX22 is not particularly sensitive to the layout since it only needs dbm for maximum output voltage. However, there are two areas that need attention: the GND pins and the supply bypassing. Connect the GND pins to the PCB ground with a ground via as close as possible, and bypass V CC to ground with a capacitor as close as possible to the part. PROCESS: BiCMOS Chip Information 6

7 TERMINATION RESISTOR NOT NEEDED IF TWO OR MORE DIRECTIONAL COUPLERS ARE USED AND CONFIGURED AS IN FIGURE. RF INPUT FROM DIRECTIONAL COUPLER Ω % 22pF 24.kΩ + A RFIN/ ENA MAX22 A2 GND Typical Operating Circuit MAX22 ENABLE LOGIC INPUT TYPE C (µf) C2 (nf) WCDMA. 4.7 NCDMA..µF V CC B GND C V CC B2 FILT C2 OUT C.µF MUST BE XR OR X7R TYPE kω TO ADC C2 47pF Package Information For the latest package outline information and land patterns, go to PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 6 WLP W6B 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, 2 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.