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The LMV221 is a 40-dB RF power detector intended for use in CDMA and WCDMA applications. The device has an RF frequency range from 50 MHz to 3.5 GHz. It provides an accurate temperature and supply-compensated output voltage that relates linearly to the RF input power in dBm. The circuit operates with a single supply from 2.7 V to 3.3 V.

The LMV221 has an RF power detection range from −45 dBm to −5 dBm and is ideally suited for direct use in combination with a 30-dB directional coupler. Additional low-pass filtering of the output signal can be achieved by means of an external resistor and capacitor. shows a detector with an additional output low pass filter. The filter frequency is set with R_S and C_S.

shows a detector with an additional feedback low pass filter. Resistor R_P is optional and lowers the trans-impedance gain (R_TRANS). The filter frequency is set with C_P//C_TRANS and R_P//R_TRANS.

The device is active for Enable = High, otherwise it is in a low power consumption shutdown mode. To save power and prevent discharge of an external filter capacitance, the output (OUT) is high-impedance during shutdown.