Allegro MicroSystems A3916GESTR-T-1

Overview

A3916GESTR-T-1 from Allegro MicroSystems is a dual DMOS full-bridge motor driver IC designed for PWM-controlled low-voltage stepper and DC motors, delivering up to 1 A per channel across 2.7–15 V supply range, with integrated charge pump, synchronous rectification, and thermal shutdown-used in compact motion control modules for industrial automation and precision positioning systems.

For engineers reviewing the A3916GESTR-T-1 datasheet, A3916GESTR-T-1 pinout, A3916GESTR-T-1 application, or A3916GESTR-T-1 equivalent, key selection criteria include its 20-pin QFN package with exposed thermal pad, fixed off-time current regulation (20–40 µs), VTRIP = 205 mV, RDS(ON,HS) = 335 mΩ typ., and fault flag signaling for TSD/OCP events.

Technical Context

The A3916GESTR-T-1 implements two independent DMOS H-bridges with internal fixed off-time PWM current control, where peak current is set by external sense resistors (ITRIP(max) ≈ 0.2 V ÷ RSENSE). Each bridge supports forward/reverse/brake/disable states via four logic inputs (IN1–IN4) and includes blanking (tBLANK = 3.1 µs typ.) to suppress false overcurrent detection during switching transients.

It integrates a charge pump for high-side gate drive, synchronous rectification to reduce power dissipation during slow-decay recirculation, and protection circuitry including UVLO (2.6 V threshold), thermal shutdown (TJ1 = 165 °C), and crossover delay (550 ns typ.) to prevent shoot-through. Sleep mode reduces quiescent current to ≤0.5 µA.

Key Specifications

Pinout & Package

The A3916GESTR-T-1 is supplied in a 4 × 4 mm, 20-terminal QFN package (suffix "ES,-1") with an exposed thermal pad for enhanced heat transfer. Pin numbering follows JEDEC MO-220WGGD; terminals 1–10 and 12–20 are functional; pins 11, 17–19 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual full-bridge motor driver applications.

Compared with TB6612FNG and DRV8833, the A3916GESTR-T-1 provides superior thermal management (37 °C/W), integrated diagnostics (FAULTn), and autonomous current regulation-making it optimal for industrial and medical motion systems requiring reliability, compactness, and deterministic fault response.

Availability

A3916GESTR-T-1 is available at Aetrix Electronics and suitable for industrial automation, medical device actuation, and smart home motor control requiring stable component supply, long-term lifecycle support, and consistent thermal performance across temperature extremes.

Supply support for A3916GESTR-T-1 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 semiconductor company specializing in high-performance magnetic sensing and power ICs for motion control, automotive, and industrial applications.

The A3916 product line delivers highly integrated, thermally robust motor drivers for compact, low-noise, and energy-efficient motion systems-designed specifically for stepper and dual-DC motor control in space-constrained environments.

FAQ

What is the maximum continuous output current per channel for the A3916GESTR-T-1?

The A3916GESTR-T-1 supports 1.0 A continuous output current per channel under typical thermal conditions (TA ≤ 85°C, 4-layer PCB). At 105°C ambient, derating applies per the thermal characteristics table-junction temperature must remain below 150°C. The 4 × 4 mm QFN package's θJA of 37 °C/W enables this rating with proper PCB copper area and thermal vias under the exposed pad.

Does the A3916GESTR-T-1 require external components for basic operation?

Yes-the A3916GESTR-T-1 requires three mandatory external components: a 0.1 µF ceramic capacitor on VCP for charge pump operation, current sense resistors on SENSE1/SENSE2 (typically 0.2–0.5 Ω), and local 100 nF decoupling on VBB. No external clock or PWM generator is needed due to its internal fixed off-time current control architecture.

How does the FAULTn pin behave during overcurrent and thermal events?

The FAULTn pin is an open-drain output pulled low during either thermal shutdown (TJ ≥ 165°C) or overcurrent protection (OCP) activation. For thermal events, FAULTn releases when junction temperature falls below 145°C (165°C − 20°C hysteresis). For OCP, FAULTn remains asserted until SLEEPn is toggled low or the VBB supply is cycled-ensuring persistent fault indication until deliberate recovery.

Can the A3916GESTR-T-1 drive a unipolar stepper motor?

No-the A3916GESTR-T-1 is designed exclusively for bipolar stepper motors (requiring two full-bridge channels per motor) or dual DC motors. It does not support unipolar stepper configurations, which rely on center-tapped windings and single-ended switching. Its IN1–IN4 logic mapping and current-sense architecture assume bidirectional winding current flow.

What is the purpose of the blanking time (tBLANK) in the A3916GESTR-T-1?

The tBLANK period (3.1 µs typ.) disables the current sense comparator output immediately after H-bridge switching to prevent false overcurrent detection caused by reverse recovery currents in internal clamp diodes or transient voltage spikes across the sense resistor. This ensures accurate current regulation during PWM transitions and avoids unnecessary fault triggering.