LMV248 Datasheet, PDF (1/11 Pages) National Semiconductor (TI) – Dual Band GSM Power Controller

September 2001
LMV248
Dual Band GSM Power Controller
General Description
The LMV248 RF power amplifier controller allows simple
implementation of transmit power control loops in GSM and
DCS/PCS and mobile phones. The LMV248 supports, GaAs
HBT and bipolar RF power amplifiers. The device operates
from a single supply of 2.5V to 5V. The LMV248 includes an
error amplifier with an input summing network, input and
output band switches, input filters, and output drivers. Ana-
log input signals processed are:
– Coupler/detector voltages from GSM and PCN band
power amplifier outputs.
– Base band DAC ramp signal.
– Temperature compensation diode voltages.
– Pre-bias voltage for faster PA control.
Selection of the GSM or PCN output driver is made using the
GSM/PCN band select pin.
The On/OFF pin allows rapid power up or shutdown of the
device during Tx or Rx slots. In the off mode, both output
drivers are set low for PA shutdown. In the on mode, the
non-active driver will remain low for continued PA shutdown.
A single external capacitor/resistor combination is used to
adjust the closed loop frequency response.
The LMV248 replaces multiple discrete parts, reducing
board area and cost. The LLP leadless package minimizes
board footprint and permits flexible optimized PCB place-
ment.
Features
n Multi-band cellular operation (example: GSM, PCN)
n Support of GaAs HBT and bipolar technology
n Shutdown mode for power save in Rx slot (0.15µA)
n Integrated ramp filter
n Built-in current source for biasing Schottky diodes
n Pre-biasing of PA control gate voltage (V_HOME)
n GPRS compliant
n External loop compensation
n Detector diode temperature compensation
n Miniature packaging: LLP-16: 4mm x 4mm x 0.8mm
Applications
n GSM mobile phone
n TDMA RF control
n Wireless LAN
n PC and PDA modules
n GPS navigation modules
Connection Diagram
16-Pin LLP
Typical Application Circuit
Top View
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© 2001 National Semiconductor Corporation DS101372
FIGURE 1.
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