Overview: .. PRODUCT SUMMARY SKY74691: Receiver for CDMA Mobile Handset Applications
Applications
• Single mode CDMA handsets After RF LNA signal amplification and filtering from the antenna, the received signal is downconverted from RF to the Intermediate Frequency (IF). The LO_IN signal (pin 39) provides a Local Oscillator (LO) port for the RF mixer. The UHF Voltage Controlled Oscillator (VCO) is buffered and amplified internally, and provides the LO to drive the LO port of a transmitter upconverter (such as Skyworks CX74002). The Variable Gain Amplifier (VGA) has a minimum dynamic range of 90 dB with a control voltage range of 0.2 to 2.7 V. A VHF oscillator operates with an internal tank circuit to provide LO frequencies for the I/Q demodulator. The noise figure, gain, and third order Input Intercept Point (IIP3) of each stage in the receiver are optimized to meet the system requirements for CDMA according to TIA/EIA-98-B/C. The design employs SiGe BiCMOS technology for low cost, high performance, and a high level of integration.
