Power Amplifier Module - LG GM360i Service Manual

3. TECHNICAL BRIEF

3.21 Power Amplifier Module

The TQM7M5005 is an extremely small (5x5x1.1mm3) multi-mode power amplifier module for GSM/EDGE
applications. This module has been optimized for high EDGE efficiency and EDGE power class E2 operation while
maintaining high GSM/GPRS efficiency. In EDGE mode, the Vramp pin provides a continuously variable bias
control to minimize current consumption during backed-off power
conditions.
The module incorporates two highly integrated InGaP power amplifier die with a CMOS controller. The CMOS
controller implements a fully integrated closed-loop power control within the module for GSM Operation. This
eliminates the need for any external couplers, power detectors, current sensing etc., to assure the output power
level. The latter is set directly from the Vramp input from the DAC. The module has Tx enable, band select, mode
(EDGE or GSM) inputs. Module construction is a low-profile over-molded land-grid array on laminate.
.Table 9 PAM pin description
Pin # Description
1 DCS/PCS in
2 MODE SELECT
 BAND SELECT (BS)
4 VBATT
5 VRAMP
6 TX_EN
7 GSM850 / 900 in
10 GSM850 / 900 out
12 DCS / PCS out
9, 1 Bypass Cap
8, 11, 14 GND
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Function
DCS/PCS RF INPUT – DC blocked
MODE = High, the PAM operation in EDGE(SPSK) mode
MODE = Low, the PAM operation in GMSK mode.
BAND SELECT = Low, Low-band active
BAND SELECT = High, High-band active
Battery supply voltage, typ..0 – 4.5 V, nom. 1.6
DAC Control signal(analog), Nominal Vramp range is 0.2 to 1.6V
GMSK mode – Controls ramp profile and output power
EDGE mode – Controls ramp profile
TX_EN = High, PA is enabled for operation
TX_EN = Low, PA is sleep mode
GSM850 / GSM900 RF input –- DC blocked
GSM850 / GSM900 RF output –- DC blocked
DCS / PCS RF output –DC blocked
Connect 0.01uF bypass capacitor as close to pin as practical
Ground
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