LMX2240 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – Intermediate Frequency Receiver

April 1995
LMX2240
Intermediate Frequency Receiver
General Description
The LMX2240 is a monolithic integrated intermediate fre-
quency receiver suitable for use in Digital European Cord-
less Telecommunications (DECT) systems as well as other
mobile telephony and wireless communications applica-
tions It is fabricated using National’s ABiC^TM IV BiCMOS
process (f_T e 15 GHz)
The LMX2240 consists of a high gain limiting amplifier a
frequency discriminator and a received signal strength indi-
cator (RSSI) The high gain limiting amplifier and discrimina-
tor 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 per-
formance demodulator for communications systems The
RSSI output can be used for channel quality monitoring
The LMX2240 is intended to support single conversion re-
ceivers This device saves power size and cost by eliminat-
ing the second local oscillator (LO) second converter (mix-
er) 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 _{Typical operation at 110 MHz}
Y _{RF sensitivity to} b_{75 dBm RSSI sensitivity to}
b82 dBm
Y _{High gain (70 dB) limiting amplifier}
Y _{Average current consumption 480 mA for DECT}
handset (burst mode)
Y a_{3V operation}
Y _{Power down mode for increased current savings}
Y _{Part of a complete receiver solution with the LMX2216}
LNA Mixer the LMX2315 20 Phase-locked Loop and
the LMX2411 Baseband Processor
Y _{Compliant to ARi}1TM _{specification}
Applications
Y _{Digital European Cordless Telecommunications (DECT)}
Y _{Portable wireless communications (PCS PCN cordless)}
Y _{Wireless local area networks (WLANs)}
Y _{Digital cellular telephone systems}
Y _{Other wireless communications systems}
Functional Block Diagram
ABiCTM and ARi1TM are trademarks of National Semiconductor Corporation
C1995 National Semiconductor Corporation TL W 11755
TL W 11755 – 1
RRD-B30M115 Printed in U S A