LMX2240

LMX2240 Intermediate Frequency Receiver April 1995 LMX2240 Intermediate Frequency Receiver General Description The LMX2240 is a monolithic integrated intermediate frequency receiver suitable for use in Digital European Cordless Telecommunications (DECT) systems as well as other mobile telephony and wireless communications applications It is fabricated using National’s ABiCTM IV BiCMOS process (fT e 15 GHz) The LMX2240 consists of a high gain limiting amplifier a frequency discriminator and a received signal strength indicator (RSSI) The high gain limiting amplifier and discriminator operate in the 40 MHz to 150 MHz frequency range and the limiter has approximately 70 dB of gain The use of the limiter and the discriminator provides a low cost high performance demodulator for communications systems The RSSI output can be used for channel quality monitoring The LMX2240 is intended to support single conversion receivers This device saves power size and cost by eliminating the second local oscillator (LO) second converter (mixer) and additional filters The LMX2240 is recommended for systems with channel bandwidths of 300 kHz to 2 5 MHz The LMX2240 is available in a 16-pin JEDEC surface mount plastic package Features Y Y Y Y Y Y Y Y Typical operation at 110 MHz RF sensitivity to b75 dBm RSSI sensitivity to b 82 dBm High gain (70 dB) limiting amplifier Average current consumption 480 mA for DECT handset (burst mode) a 3V operation Power down mode for increased current savings...