PRELIMINARY
ML2751 Power Amplifier and LNA
GENERAL DESCRIPTION
The 2751 is a 900 MHz ISM band radio front-end intended
for use in half duplex radio applications such as cordless
phones and FCC Part 15 compliant devices. It integrates a
power amplifier (PA), a Low Noise Amplifier (LNA), Pin
Diode drivers for an external transmit/receive switch, and
control circuits. The 100mW power amplifier has output
power control with a >20dB range. The ML2751 can be
used to increase battery life and offers output power ramp
control in TDMA applications. An internal LNA eliminates
the need for a discrete design. PIN diode drivers control
the transmit/receive switch directly. Internal logic
individually enables the LNA, PA, and PIN diode drivers.
A power down mode to minimize current consumption is
included.
FEATURES
n
Fully integrated Power Amplifier, Low Noise Amplifier,
and PIN diode drivers
n
100mW Power Amplifier
n
Single supply, 2.7V to 4.5V operating range
n
PA output: +21 dBm at 3.0V, 35dB gain, 35%
efficiency at 3.3V after harmonic filter; integrated PA
ramp control
n
LNA: noise figure of 2.5dB, –15dBm 3
rd
-order intercept
point, and –25dBm
APPLICATIONS
n
900 MHz FCC Part 15 Radios
n
900 MHz Cordless Telephones
n
TDD / TDMA Radios
SIMPLIFIED BLOCK DIAGRAM
ML2751
PA
TRFO
TRFI
Watch
Osc.
Xtal
RAMP
GEN.
POWER
CONTROL
AMP
TPS, PAON, FEEN
PIN
CONT.
BLOCK
RF PIN
DIODE
SWITCH
PINB
PIN DIODE
DRIVERS
LOOP
FILTER
ML2721
Baseband IC
(MODEM
CODEC
Protocol
MMI Control)
RLNI
LNA
Memory
RRFO
Keypad
Display
Mic.
Speaker
Ringer
BATTERY
DATASHEET
January, 2000
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
