Description
The SKY77528 is a transmit Front-End Module (FEM) designed for quad-band Global System for
Mobile Communications (GSM), General Packet Radio Service (GPRS), and Enhanced Data Rate for
GSM Evolution (EDGE) handsets and modules.
The SKY77528 consists of a GSM850/EGSM900 PA block and a DCS1800/PCS1900 PA block,
impedance-matching circuitry for 50 Ωinputs and outputs, a multi-function PA control block, low
pass harmonic rejection filter, and a transmit/receive antenna switch.
Two Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated onto an Indium Gallium
Phosphide (InGaP) die; one block supports the GSM850 and EGSM900 bands, the other supports the DCS1800 and PCS1900 bands. The InGaP die, the Silicon(Si) die, the PHEMT die, and the passive components are mounted on a multi-layer laminate substrate. The entire assembly is encapsulated with plastic overmold.

FEATUREs
• High efficiency:
- GSM850, 45% (peak)
- EGSM900, 45% (peak)
- DCS1800, 40% (peak)
- PCS1900, 40% (peak)
• Low-loss PHEMT RF antenna switch
• Detector output: linear dB/V
• Closed loop GMSK mode power control
• Low VRAMP current
• Low VBATT detection
• Integrated temperature sensor
• Small Package
- 8 mm x 6 mm
• Low Profile
- 1.1 mm Max.

APPLICATIONs
• Quad-band, cellular handsets:
- Class 4 GSM850/GSM900
- Class 1 DCS1800/PCS1900
- Class E2 GSM850/EGSM900
- Class E2 DCS1800/PCS1900
- Class 12 EGPRS multi-slot operation