LMV221 Datasheet | National Semiconductor

Description The LMV221 is a 40 d B 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 pensated output voltage that relates linearly to the RF input power in d Bm. The circuit operates with a single supply from 2.7V to 3.3V. The LMV221 has an RF power detection range from - 45 d Bm to - 5 d Bm and is ideally suited for direct use in bination with a 30 d B directional coupler. Additional low-pass filtering of the output signal can be realized by means of an external resistor and capacitor. Figure (a) shows a detector with an additional output low pass filter. The filter frequency is set with RS and CS. Figure (b) shows a detector with an additional feedback low pass filter. Resistor RP is optional and will lower the Trans impedance gain (RTRANS). The filter frequency is set with CP//CTRANS and RP//RTRANS. 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. The LMV221 power detector is offered in the small 2.2 mm x 2.5 mm x 0.8 mm LLP package. Features - - - - - - - 40 d B linear in d B power detection range Output voltage range 0.3 to 2V Shutdown Multi-band operation from 50 MHz to 3.5 GHz 0.5 d B accurate temperature pensation External configurable output filter bandwidth 2.2 mm x 2.5 mm x 0.8 mm LLP 6 package Applications - - - - UMTS/CDMA/WCDMA RF power control GSM/GPRS RF power control PA modules IEEE 802.11b, g (WLAN) Typical Application (a) LMV221 with output RC Low Pass Filter (b) LMV221 with feedback (R)C Low Pass Filter © 2006 National Semiconductor Corporation .national. .. Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for...