The SKY74963 RF transceiver is a highly integrated device for multi-band Global System for Mobile Communications (GSM) or General Packet Radio Service (GPRS) applications. The device requires a minimal number of external components to complete a GSM radio subsystem. The SKY74963 supports GSM850, EGSM900, DCS1800, and PCS1900 applications. The receiver also supports Enhanced Data for GSM Evolution (EDGE) downlink applications. The receive path implements a direct down-conversion architecture that eliminates the need for Intermediate Frequency (IF) components. The SKY74963 consists of three integrated Low Noise Amplifiers (LNAs), a quadrature demodulator, tunable receiver baseband filters, and a DC Offset Correction (DCOC) sequencer. In the transmit path, the device consists of an In-phase and Quadrature (I/Q) modulator within a frequency translation loop designed to perform frequency up-conversion with high output spectral purity. This loop also contains a phase-frequency detector, charge pump, mixer, programmable dividers, and high power transmit Voltage Controlled Oscillators (VCOs) with no external tank required. With the integrated gain controller (and an integrator ), the device realizes the Power Amplifier Control (PAC) functionality when combined with a coupler, a Radio Frequency (RF) detector, and a Power Amplifier (PA). The SKY74963 also features an integrated, fully programmable, sigma-delta fractional-N synthesizer suitable for GPRS multi-slot operation. Except for the loop filter, the frequency synthesizer function, including a wideband VCO, is completely on-chip. The reference frequency for the synthesizer is supplied by the integrated crystal oscillator circuitry.