SKY77542

Tx–Rx iPAC™ FEM for Dual-Band GSM / GPRS (880-915 MHz and 1710–1785 MHz)


Please note: this product is being discontinued and is not recommended for new designs.

The SKY77542 is a transmit and receive front-end module (FEM) with Integrated Power Amplifier Control (iPAC™) for dual-band cellular handsets comprising GSM900 and DCS1800 operation. Designed in a low profile, compact form factor, the SKY77542 offers a complete Transmit VCO-to- Antenna and Antenna-to-Receive SAW filter solution. The FEM also supports Class 12 General Packet Radio Service (GPRS) multi-slot operation.

The module consists of a GSM900 PA block and a DCS1800 PA block, impedance-matching circuitry for 50 Ω input and output impedances, Tx harmonics filtering, high linearity and low insertion loss PHEMT RF switches, diplexer and a Power Amplifier Control (PAC) block with internal current sense resistor. A custom BiCMOS integrated circuit provides the internal PAC function and decoder circuitry to control the RF switches. The two Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated onto a single Gallium Arsenide (GaAs) die. One PA block supports the GSM900 band and the other PA block supports the DCS1800 band. Both PA blocks share common power supply pads to distribute current. The output of each PA block and the outputs to the two receive pads are connected to the antenna pad through PHEMT RF switches and a diplexer. The GaAs die, PHEMT die, Silicon (Si) die and passive components are mounted on a multi-layer laminate substrate. The assembly is encapsulated with plastic overmold.

Specifications

Frequency (MHz)
880-915
1710-1785
DescriptionTx-Rx iPAC™ FEM for Dual-Band GSM/GPRS
GSM900
DCS1800
Typical Output Power (dBm) GSM
33.8
32.0
Typical PAE (%)
45.5
39.5
Supply Voltage (V)2.9-4.8
PackageMCM, 30-pin
Package (mm)7 x 6 x 0.9

Features

  • High efficiency
    - GSM850 45.0%
    - PCS1900 38.5%
  • Low transmit supply current
    - GSM850 1.26 A
    - PCS1900 0.93 A
  • Internal ICC sense resistor for iPAC
  • Closed loop iPAC
  • 50 Ω matched Input/Output
  • Tx–VCO-to-antenna and antenna-to-Rx-SAW filter RF interface
  • Tx harmonics below –33 dBm
  • PHEMT RF switches afford high linearity, low insertion loss, and less than 20 μA supply current in receive modes
  • Small outline: 7 x 6 mm
  • Low profile: 0.9 mm
  • Compatible with multiple logic families
  • Low APC current: 25 μA

Product Documents