SA1620
DESCRIPTION
The SA1620 is a bined receive (Rx) and transmit (Tx) front-end for GSM cellular telephones. The receive path contains two low noise amplifiers (LNA1 and LNA2) with four switchable attenuation steps. A Gilbert Cell mixer in the receive path down-converts the RF signal to a first IF of 70 to 500 MHz. A second Gilbert Cell in the transmit path transposes a GMSK or phase modulated IF to RF by image reject mixing and has a fixed IF of 400 MHz. A buffered LO signal is fed to Rx and Tx mixers. Rx or Tx path or the entire circuit may be powered-down.
- Feedthrough attenuation LNA1 to Rx mixer ≥ 35d B
- Tx power adjustable from -3 to +12d Bm by external resistor
- Direct supply: 2.7V to 5.5V
- Battery supply voltage VBATT = 3.3V to 7.5V or direct supply
- Two DC regulators programmable for 3.0V, 3.4V, 3.7V or 5.1V
- Low current consumption: 28m A for Rx or 59m A for Tx
- Fully patible with SA1638 GSM IF Digital I/Q circuit
APPLICATIONS
FEATURES
- Excellent noise figure: <2d B for the...
