GENERAL DESCRIPTION

The OM5156M BICMOS device integrates prescalers, programmable dividers, and phase comparators to implement two phase-locked loops. The device is designed to operate from 3 NiCd cells, in pocket phones, with low current and a wide supply voltage range from 2.7 to 5.5 V.

The principal synthesizer operates at RF input frequencies up to 2 GHz the auxiliary synthesizer operates at 300 MHz. The auxiliary loop is intended for the first IF or to transmit offset loop-frequency settings. Each synthesizer has a fully programmable reference divider. All divider ratios are supplied via a 3-wire serial programming bus.

FEATURES

• Low current from 3 V supply

• Fully programmable RF divider

• 3-line serial interface bus

• Second synthesizer to control first IF or offset loop frequency

• Independent fully programmable reference dividers for each loop, driven from external crystal oscillator

• Dual phase detector outputs to allow fast frequency switching

• Dual power-down modes.

APPLICATIONS

• 2 GHz mobile telephones

• Portable battery-powered radio equipment.