Lge Internal Use Only - LG -E510 Service Manual

3. TECHNICAL BRIEF
3.6.3 GSM PAM (U1001, SKY77336)
SKY77336 Power Amplifier Module (PAM) is designed in a compact form factor for quad-band cellular
handsets comprising GSM850/900, DCS1800 and PCS1900, supporting Gaussian Minimum-Shift
Keying (GMSK) and Polar Enhanced Data for GSM Evolution (EDGE) modulation. Class 12 General
Packet Radio Service (GPRS) multi-slot operation is also supported.
The module consists of GSM850/900 PA and DCS1800/PCS1900 PA blocks, impedance matching
circuitry for 50 Ù input and output impedances, and a Power Amplifier Control (PAC) block. The
custom CMOS integrated circuit provides the internal PAC function and interface circuitry. Fabricated
in InGaP/GaAs, the Heterojunction Bipolar Transistor (HBT) PA blocks support the GSM850/900 bands
and DCS1800/PCS1900 bands. Both PA blocks share common power supply pads to distribute
current. The InGaP/GaAs die, Silicon (Si) controller die, and passive components are mounted on a
multi-layer laminate substrate and the entire assembly is encapsulated with plastic overmold.
RF input and output ports of the SKY77336 are internally matched to a 50 Ù load to reduce the
number of external components for a quad-band design. Extremely low leakage current
(10 ìA, typical) of the PAM module maximizes handset standby time.
[Figure 1.9] SKY77336 Block Diagram

LGE Internal Use Only

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