PRELIMINARY
ML2731 PA Bias Controller
GENERAL DESCRIPTION
The ML2731 is a power amplifier (PA) bias controller with
support circuits for a typical radio transceiver. The IC
integrates a PA bias controller, a PA DC switch, a crystal
oscillator circuit, a negative voltage generator and two
voltage regulators. It can be used with GaAs FETs and
silicon bipolar devices.
Micro Linear’s ML2731, along with the ML2712 and the
ML2713, form a complete transceiver solution for the 2.4
GHz IEEE802.11 communication standard, as well as
other wireless ISM communication products.
In addition to supporting Micro Linear’s transceiver chip
set, the ML2731 can stand alone as:
A compact bias voltage controller
A compact negative voltage generator
A compact crystal oscillator
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Sets PA current and power output using a bias control
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Integrates a PA DC supply switch
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Prevents PA power-on if negative voltage is not present
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Integrates all circuits needed for supporting a crystal
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Incorporates a fast starting, high switching frequency,
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Contains voltage regulators for an oscillator, a negative
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Requires less than 1mA of current when powered down
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Supply voltage ranges from 3.3V to 5.5V
APPLICATIONS
voltage generator and a 50mA 3.0V LDO output
negative voltage generator requiring only small
ceramic capacitors
oscillator with 10MHz to 40MHz frequency range
loop
FEATURES
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Cellular and Cordless Radios
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WLAN Radios
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Radios with GaAs FET Power Amplifiers
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Fixed and Mobile radio transceivers
SIMPLIFIED BLOCK DIAGRAM
ML2731
VPA
PA on/off switch
and current sense
PAEN
ICON
VBIAS
Bias Control
NEGEN
VNEG
C1
C2
Negative voltage
generator
Voltage
Regulator
Crystal
Oscillator
XIN
Crystal
XOUT
Sine & square
wave drivers
PDN
REGO
SINO
CLKO
GaAs FET Power Amplifier
ML2712
ML2713
Radio
Baseband Controller
(e.g. MSM7730B)
PRELIMINARY DATASHEET
January, 2000
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
