20 to 55 V / 20 A Output, Compact, Fast Response, Step Down RFPoL (Point of Load) Voltage Regulator

    Key Features

    • Input Voltage Range: Up to 150 V
    • Output Voltage Range: 20 V to 55 V
    • Gate Driver Support: Power-GaN or Traditional FETs
    • Fixed Frequency Current-Mode Operation:
      • Low Noise: 2.4 mVRMS @ 50 V (100 Hz to 100 kHz)
      • Stable Loop, Phase-margin: ~ 60°
      • Fast Response, Loop BW: ~ 100 kHz
      • 500 kHz to 900 kHz, Programmable
    • Protections: UVLO, OVLO, OVP, UVP, OCP, TS
    • 4 mm × 4 mm, 0.4-mm pitch, 25-pin QFN
    • Ready-to-Use Reference Circuit Design Available

    The ACT43850, a part of Qorvo’s RFPoL (RF Point of Load) regulator family, is the second stage device of a three-chip pulse load power supply solution for radar-type systems. Together with companion devices ACT43950 and ACT43750, the device forms a compact, complete power supply solution for GaN / GaAs RF power amplifier (PA) devices, demanding fast transient, high current pulse load. This 3-chipset makes an RF transmitter (TX) module significantly smaller in, size/volume, cost, component count and development cycle.

    The 1st stage ACT43950 converts a source dc voltage into a regulated dc constant-current (CC) charging bulk capacitor(s) at its output. From the bulk capacitor(s), this ACT43850 regulates dc output constant voltage (CV) for the drain power of PAs. The 3rd stage ACT43750 controls the PAs' drain switching and gate bias.

    The ACT43850 is a step-down (buck) dc-dc controller, with external power FET devices. This fast response, fixed frequency, current-mode converter offers stable regulation for low EMI and noise. The output voltage level can be programmed using analog and/or I2C interfaces for the initialization default setpoint and on-the-fly dynamic target.

    The ACT43850 is available in a 25-pin, 4 mm x 4 mm, 0.4-mm pitch QFN package, based on a standard pinout 32-pin QFN, several pins removed to maintain creepage distance(s) for high voltage nodes.

    Typical Applications

      • RF GaN / GaAs PA Power Supply
      • Military Radar System
      • Civilian Radar System
      • Laser Drivers
      • Light Beacons
    Topology Step-Down
    Min Input Voltage(V) 45
    Max Input Voltage(V) 150
    Min Output Voltage(V) 20
    Max Output Voltage(V) 55
    Max Output Current(A) 20
    Pin Count 25
    Configurable Output Voltage Step Size(mV) 1,000
    Configurable Output Current Step Size(mA) 120
    Output Noise(mVrms) 2.4
    Operation Frequency(kHz) 500 to 900
    Features External Clock Syncing with Selectable Clock Edge
    Package Type QFN, 25-pin
    Package(mm) 4.0 x 4.0
    RoHS Yes
    Lead Free Yes
    Halogen Free Yes
    ITAR Restricted No
    ECCN EAR99