BENEFITS and FEATURES
• Wide Operating Range
• Vin = 10V to 55V
• Vgate = -6V to -1.5V
• RF PA Biasing Solution
• Turn on and off sequencing
• Negative gate voltage supply
• Supports GaN and Silicon FETs
• High-speed drain switching
• Autonomous Bias Point Calibration
• Autonomous IDQ(DRAIN) calibration
• Resistor Setpoint Range: 10mA to 2A
• Digitally adjustable ±31% of setpoint in 1% steps
• Space and Cost savings
• Fully integrated gate drive voltage
• High switching frequency: 2.05 MHz
• Integrated FETs and small chip inductor
• 37-pin, 5 mm x 5 mm, 0.4-mm pitch QFN package
• High-Performance Negative Gate Drive Supply
• REGG input voltage: +12V (TYP)
• REGG output voltage: -6V to -1.5V by 732μV step
• REGG output source current: 300mA
• REGG output sink current: -100mA
• REGG output noise: <200μVRMS
• Protection
• UVLO, OVLO, OVP, UVP, OCP, TSD

APPLICATIONS
• Military Radar System
• Civilian Radar System
• RF GaN / GaAs PA Power Supply

GENERAL DESCRIPTION
The ACT43750, part of Qorvo’s RF POL regulator family,
is the last stage of a three-chip radar power supply solution.
This three-stage solution, developed with the
ACT43950, ACT43850, and ACT43750, forms a compact,
complete power supply system for radio frequency
(RF) power amplifiers (PAs) that demand fast transient,
high current pulse loads. The first stage, ACT43950
converts a high voltage dc input voltage into a regulated
dc constant-current (CC) to charge bulk capacitor. The
second stage, ACT43850, regulates the capacitor voltage
into a tightly regulated DC voltage to power the
drain for GaN RF power amplifiers.
The third stage, ACT43750, provides several functions
specifically designed to optimize GaN performance. It
operates either standalone or as the third stage in a
multiple stage power solution. It provides the RF PA
negative gate voltage using an ultra-low noise inverting
buck dc-to-dc regulator with integrated FETs and programmable
voltage reference. It provides the required
GaN power up and power down sequencing between
the drain and gate voltages. All GaN RF PAs require
calibrating the gate voltage to set the desired operating
point. The ACT43750 automatically calibrates and
stores the optimal gate voltage. This operating point
changes with time and temperature. The IC can recalculate
and adjust the optimal gate voltage in the field
without waiting for a maintenance cycle. The ACT43750
also enables drain switching in pulsed radar applications.
The ACT43750 is available in a 37-pin, 5 mm x 5 mm,
0.4 mm pitch QFN package.