Please note: this product is being discontinued and is not recommended for new designs.
The SKY77543 is a transmit and receive front-end module (FEM) with Integrated Power Amplifier
Control (iPAC™) for dual-band cellular handsets comprising GSM850 and PCS1900 operation.
Designed in a low profile, compact form factor, the SKY77543 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 GSM850 PA block and a PCS1900 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 GSM850 band and the other PA
block supports the PCS1900 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.