LMH2100

LMH2100 50 MHz to 4 GHz 40 dB Logarithmic Power Detector for CDMA and WCDMA www.DataSheet4U.com November 28, 2007 LMH2100 50 MHz to 4 GHz 40 dB Logarithmic Power Detector for CDMA and WCDMA General Description The LMH2100 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 4 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 2.7V to 3.3V. The LMH2100 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 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 LMH2100 power detector is offered in the small 0.4 mm pitch micro SMD package. Features ■ ■ ■ ■ ■ ■ ■ 40 dB linear in dB power detectio...