Description
The Si4133G is a monolithic integrated circuit that performs both IF and dual-band RF synthesis for GSM and GPRS wireless communications applications. The Si4133G includes three VCOs, loop filters, reference and VCO dividers, and phase detectors. Divider and power down settings are programmable through a three-wire serial interface.

Features
■ Dual-Band RF Synthesizers
    ● RF1: 900 MHz to 1.8 GHz
    ● RF2: 750 MHz to 1.5 GHz
■ IF Synthesizer
    ● IF: 500 MHz to 1000 MHz
■ Integrated VCOs, Loop Filters, Varactors, and Resonators
■ Minimal External Components Required
■ Fast Settling Time: 140 µs
■ Low Phase Noise
■ Programmable Power Down Modes
■ 1 µA Standby Current
■ 18 mA Typical Supply Current
■ 2.7 V to 3.6 V Operation
■ Packages: 24-Pin TSSOP and 28-Pin MLP

Applications
■ GSM, DCS1800, and PCS1900 Cellular Telephones
■ GPRS Data Terminals
■ HSCSD Data Terminals