SKY74068-11

PRODUCT SUMMARY SKY74068-11: Dual-Band, Dual-Mode Transmitter for CDMA, AMPS, and PCS Mobile Handset Applications Applications Dual-band, dual-mode handsets Cellular and PCS band phones − CDMA and AMPS modes in the cellular band − CDMA mode in the PCS band Description The SKY74068-11 transmitter is a highly integrated device for dual-band Code Division Multiple Access (CDMA) handsets in the cellular CDMA, Advanced Mobile Phone System (AMPS), and Personal Communications System (PCS) modes. The device requires a minimum number of external components to complete a CDMA radio subsystem. Included on-chip are the baseband filter, direct upconversion In-Phase and Quadrature (I/Q) mixers, variable gain power amplifier (PA) drivers, a fully integrated Voltage Controlled Oscillator (VCO) with Local Oscillator (LO) generation blocks, and a dual-mode fractional-N/integer-N Phase Locked Loop (PLL). External components needed for operation include bias resistors, bypass capacitors, and passives to comprise the PLL loop filter. The signal enters the chip as an analog baseband I/Q signal. It is filtered by the baseband filter and upconverted to the desired RF transmit frequency. The signal is amplified by one of two upconverters, depending on whether the chip is operating in cellular or PCS mode. The resulting signal is fed through the appropriate PA driver stage to provide variable output power and to drive the external PA. The signal is then filtered by an external Surface Acoustic W...