The LMX243x devices are high performance frequency synthesizers with integrated dual modulus prescalers. The LMX243x devices are designed for use as RF and IF local oscillators for dual conversion radio transceivers.
A 32/33 or a 16/17 prescale ratio can be selected for the 5.0 GHz LMX2434 RF synthesizer. An 8/9 or a 16/17 prescale ratio can be selected for both the LMX2430 and LMX2433 RF synthesizers. The IF circuitry contains an 8/9 or a 16/17 prescaler. Using a proprietary digital phase locked loop technique, the LMX243x devices generate very stable, low noise control signals for RF and IF voltage controlled oscillators. Both the RF and IF synthesizers include a two-level programmable charge pump. Both the RF and IF synthesizers have dedicated Fastlock circuitry with integrated timeout counters. Furthermore, only a single word write is required to power up and tune the synthesizers to a new frequency.
Serial data is transferred to the devices via a three-wire interface (DATA, LE, CLK). A low voltage logic interface allows direct connection to 1.8V devices. Supply voltages from 2.25V to 2.75V are supported . The LMX243x family features low current consumption: