Datasheet LT5538 (Analog Devices)

LT5538 40MHz to 3.8GHz RF Power Detector with 75dB Dynamic Range
FEATURES DESCRIPTION
■ Frequency Range: 40MHz to 3.8GHz The LT®5538 is a 40MHz to 3800MHz monolithic logarith- ■

75dB

Log

Linear Dynamic Range mic RF power detector, capable of measuring RF signals ■

Exceptional Accuracy over Temperature over a wide dynamic range, from –75dBm to 10dBm. The ■

Linear DC Output vs. Input Power in dBm RF signal in an equivalent decibel-scaled value is precisely ■

–72dBm Detection Sensitivity converted into DC voltage on a linear scale. The wide linear ■

Single-ended RF Input dynamic range is achieved by measuring the RF signal us- ■

Low Supply Current: 29mA ing cascaded RF limiters and RF detectors. Their outputs ■

Supply Voltage: 3V to 5.25V are summed to generate an accurate linear DC voltage ■

8-lead DFN 3mm × 3mm package proportional to the input RF signal in dBm. The LT5538 delivers superior temperature stable output (within ±1dB
APPLICATIONS
over full temperature range) from 40MHz to 3.8GHz. The output is buffered with a low impedance driver. ■ Received Signal Strength Indication (RSSI) , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ■ RF Power Measurement and Control All other trademarks are the property of their respective owners. ■ RF/IF Power Detection ■ Receiver RF/IF Gain Control ■ Envelope Detection ■ ASK Receiver
TYPICAL APPLICATION Output Voltage and Linearity Error 40MHz - 3.8GHz Logarithmic RF Detector vs Input Power
2.0 3 V LT5538 CC = 5V AT 880 MHz EN ENBL OUT VOUT 1.7 2 RF IN+ CAP+ LINEARITY ERROR (dB) INPUT 1nF IN– CAP– 1.4 1 56 1nF GND V 5V CC (V) 1.1 0 5538 TA01 9 OUTV 0.1μF 100pF 0.8 –1 0.5 TA = –40°C –2 TA = 25°C TA = 85°C 0.2 –3 –75 –65 –55 –45 –35 –25 –15 –5 5 INPUT POWER (dBm) 5538 TA02 5538f 1