2.3 GHz to 2.4 GHz
WiMAX Power Amplifier
ADL5570
Rev. 0
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FEATURES
Fixed gain of 29 dB
Operation from 2.3 GHz to 2.4 GHz
EVM ≤ 3% at P
OUT
= 25 dBm with 16 QAM OFDMA
Input internally matched to 50 Ω
Power supply: 3.2 V to 4.2 V
Quiescent current
130 mA in high power mode
70 mA in low power mode
Power-added efficiency (PAE): 20%
Multiple operating modes to reduce battery drain
Low power mode: 100 mA
Standby mode: 1mA
Sleep mode: <1 μA
APPLICATIONS
WiMAX/WiBro mobile terminals
FUNCTIONAL BLOCK DIAGRAM
06729-001
RFOUT
CC1
CFLT
STBY
VREG
MODE
CC2
OM
RFIN
FIRST
STAGE
SECOND
STAGE
THIRD
STAGE
IM1 IM2 IM3
BIAS_2BIAS_1 BIAS_3
Figure 1.
GENERAL DESCRIPTION
The ADL5570 is a high linearity 2.3 GHz to 2.4 GHz power
amplifier designed for WiMAX terminals using TDD operation
at a duty cycle of 31%. With a gain of 29 dB and an output
compression point of 31 dBm at 2.35 GHz, it can operate at
an output power level up to 26 dBm while maintaining an EVM
of ≤3% (OFDM 16 or 64 QAM) with a supply voltage of 3.5 V.
PAE is 20% @ P
OUT
= 25 dBm.
The ADL5570 RF input is matched on-chip and provides an
input return loss of less than −10 dB. The open-collector output is
externally matched with strip-line and external shunt capacitance.
The ADL5570 operates over a supply voltage range from 3.2 V
to 4.2 V with a supply current of 440 mA burst rms when
delivering 25 dBm (3.5 V supply). A low power mode is also
available for operation at power levels of ≤10 dBm with
optimized operating and quiescent currents of 100 mA and
70 mA, respectively. A standby mode is available that reduces
the quiescent current to 1 mA, which is useful when a TDD
terminal is receiving data.
The ADL5570 is fabricated in a GaAs HBT process and is packaged
in a 4 mm × 4 mm, 16-lead, Pb-free RoHS-compliant LFCSP
that uses an exposed paddle for excellent thermal impedance.
It operates from −40°C to +85°C.
