Allegro MicroSystems A4930GETTR-T

Overview

A4930GETTR-T from Allegro MicroSystems is an AEC-Q100 qualified single-phase brushless DC fan pre-driver IC designed to control four external N-channel MOSFETs in high-current PWM fan applications. It integrates synchronous rectification, thermal shutdown with 15°C hysteresis, rotor lock detection, dead time protection, and dual regulated supplies (VREG5 at 5 V/15 mA and VREG8). It operates across –40°C to 105°C ambient and drives automotive cabin cooling fans.

For engineers reviewing the A4930GETTR-T datasheet, A4930GETTR-T pinout, A4930GETTR-T application, or A4930GETTR-T equivalent, key selection criteria include its 28-pin QFN-ET package with exposed thermal pad, 700–1300 ns programmable dead time, internal 15–27 kHz PWM frequency, Hall-based commutation support, and integrated lock detect timing via CLD capacitor.

Technical Context

The A4930GETTR-T implements a Hall-sensor-commutated full-bridge gate driver architecture with independent high-side (GHA/GHB) and low-side (GLA/GLB) outputs, each capable of sourcing/sinking ≥20 mA with 40 Ω pulldown resistance. Its control logic accepts either analog speed input (SIN/SMIN) or direct PWM input, converting duty cycle to a 1.5–3.5 V analog signal for current regulation.

Protection is implemented via multiple independent circuits: VBB undervoltage lockout (7.5–7.85 V enable threshold), VCP UVLO (5.4 V), thermal shutdown (165°C trip, 15°C hysteresis), and lock detect (programmable via CLD capacitor, 1 s on-time / 15 s off-time retry). Synchronous rectification is enabled during PWM off-cycles to bypass MOSFET body diodes and reduce power loss.

Key Specifications

Pinout & Package

Package: 28-pin QFN (5 mm × 5 mm, 0.90 mm nominal height) with exposed thermal pad (suffix ET); RoHS-compliant, 100% matte tin leadframe plating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-phase BLDC fan pre-driver applications.

Compared with MP6532DS-LF-Z and DRV10983ZRTVT, the A4930GETTR-T uniquely supports Hall-sensor commutation in a single-phase configuration with external MOSFET flexibility, AEC-Q100 qualification, and programmable lock detect - making it the only viable option for automotive-grade, high-current, Hall-based fan control.

Availability

A4930GETTR-T is available at Aetrix Electronics and suitable for automotive HVAC systems, engine bay cooling modules, and industrial server chassis requiring stable component supply, AEC-Q100 compliance, and high-temperature operation up to 105°C ambient.

Supply support for A4930GETTR-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance magnetic sensing and power IC solutions, founded in 1989 and headquartered in Manchester, NH.

The A4930 product line delivers Hall-commutated pre-driver ICs optimized for single-phase brushless DC fan control in automotive and industrial environments where reliability, thermal robustness, and integrated protection are critical.

FAQ

What is the operating temperature range for the A4930GETTR-T?

The A4930GETTR-T is rated for an ambient operating temperature range of –40°C to 105°C and is AEC-Q100 qualified, making it suitable for under-hood automotive applications. Its thermal shutdown activates at 165°C junction temperature with 15°C hysteresis, and the maximum allowable junction temperature is 150°C. The device's RθJA of 32°C/W (on a 4-layer PCB) enables stable operation within this range when proper thermal design is implemented.

Does the A4930GETTR-T integrate MOSFETs or require external ones?

The A4930GETTR-T is a pre-driver IC and does not integrate power MOSFETs - it requires four external N-channel MOSFETs arranged in a full-bridge configuration. Its gate drivers (GHA/GHB/GLA/GLB) provide 7–8.5 V output swing with ≥20 mA drive capability and 40 Ω pulldown resistance. This architecture allows designers to select MOSFETs optimized for voltage, current, and thermal requirements specific to their fan application.

How does the A4930GETTR-T implement rotor lock detection?

The A4930GETTR-T detects rotor lock by monitoring the FG output signal: if no FG transition occurs within the time window defined by the CLD capacitor (tLD = CLD × 10 s/µF), it asserts RD high and disables the appropriate source driver while holding both sink drivers on. After a 1 s on-time, it enters a 15 s off-time retry cycle. This behavior is fully programmable and independent of Hall input - ensuring reliable stall detection even during low-speed operation.

Can the A4930GETTR-T operate without a Hall sensor?

No - the A4930GETTR-T requires differential Hall sensor inputs (HP/HN) for commutation and is not compatible with back-EMF sensing. Its functional block diagram, pinout, and electrical specifications (e.g., Hall input common-mode range, threshold, and hysteresis) confirm Hall-based operation as fundamental to its architecture. Attempting to use it without a Hall sensor will prevent proper motor rotation and may trigger lock detect faults.

What are the key decoupling requirements for the A4930GETTR-T?

The A4930GETTR-T requires specific decoupling: VREG5 and VREG8 each need a 0.1 µF ceramic capacitor to GND; CP1 and CP2 require 0.22 µF and 0.1 µF respectively; VCP needs a 10 µF bulk capacitor; and the SS, CPWM, and CLD pins require capacitors sized per design equations (0.47 µF, 470 pF, and variable). All GND pins plus the exposed thermal pad must connect to a low-impedance ground plane via multiple vias to ensure stable operation and thermal performance.