SKY74076

www.DataSheet4U.com PRODUCT SUMMARY SKY74076: Receiver for Dual-Band CDMA and GPS Mobile Handset Applications Applications CDMA and GPS phones stage cellular LNA (high, mid, and bypass) and a high gain GPS LNA. After RF LNA signal amplification and filtering from the antenna, the received signal is mixed down from RF to IF. There are separate mixers for CDMA cellular and GPS modes. The CDMA mixer has balanced outputs for the IF SAW filters and can be combined externally to mate to a single-ended SAW filter. The GPS mixers have a differential output for an external LC bandpass filter. After IF filtering, the IF signal is amplified by a Variable Gain Amplifier (VGA) and sent to an I/Q demodulator, resulting in baseband I/Q signals at the output. The SKY74076 is also designed with two Local Oscillator (LO) input ports, one for the CDMA mixer and one for the GPS mixer. These mixers operate at different RF frequency inputs, but have the same IF frequency output. This usually refers to a single IF (SIF) plan at 183.6 MHz. The CELL_LO signal (pin 30) provides an LO port for the CDMA cellular mixer. In the cellular band, an internal divider divides the frequency by two, which provides the LO input to the cellular mixer. Only one external VCO is required for the UHF PLL. Additionally, the mixer LO signal is coupled and amplified internally, which provides another RF signal to drive the transmitter upconverter LO port. The VGA has a minimum dynamic range of 90 dB with a control vol...