RF142
Heterojunction Bipolar Transistor Power Amplifier Dual-Band Controller
for GSM and PCS Applications
The RF142 Power Amplifier (PA) controller is a highly integrated, monolithic device
optimized for use in 900 MHz, 1800 MHz, and 1900 MHz Global System For
Mobile communications® (GSM®) and other Time Division Multiple Access (TDMA)
applications. The control current output from the RF142 can be used to control the
transmit power of a dual or multi-band Heterojunction Bipolar Transistor (HBT) PA.
The device consists of two sections: an RF detector, and a gain controller. The
RF142, when combined with a PA and a coupler, forms a closed PA control loop,
where the PA output power is controlled by a single analog reference voltage,
typically supplied by the baseband.
The RF142 device package and pin configuration are shown in Figure 1. The signal
pin assignments and functional pin descriptions are specified in Table 1. An RF142
block diagram is shown in Figure 2.
Features
• RF PA controller for use with HBT PAs
• 50 dB detector dynamic range
• Broadband, logarithmic power detector (800 MHz
to 2000 MHz)
• Logarithmic RF power detector requires no
external diodes
• Integrator and gain shaping block enhance loop
stability and linearity
• Three-cell battery operation (2.7 V to 5.0 V)
• Standby mode with 20 µA of current consumption
• 20-pin Thin Shrink Small Outline Package
(TSSOP)
Applications
• Transmit power control for dual or multi-band
GSM digital cellular handsets
Data Sheet
GND1
1
VREF
2
VMP
3
VAPC+
4
VAPC-
5
ENABLE
6
RFPC+
7
RFPC-
8
GND2
9
VCC1
10
20
VCC2
19
VPCGSM
18
VPCDCS
17
BAND
16
AUX-
15
AUX+
14
CAP-
13
CAP+
12
NC
11
NC
100774A-1_090700
Figure 1. RF142 Pin Configuration – 20-Pin TSSOP
Conexant
Proprietary Information and Specifications are Subject to Change
Doc. No. 100774B
September 7, 2000