Diodes Incorporated AH5773-FDC-7

Overview

AH5773 from Diodes Incorporated is a single-chip BLDC motor driver IC with integrated Hall-effect latch sensor, full-bridge H-bridge (RON_TOTAL ≤ 1.9 Ω @12V/500mA), soft-switching commutation, and tachometer (FG) output. It drives single-coil fans/motors at 2.4–18V supply, supports PWM or voltage-based speed control, and delivers rotor lock protection with auto-restart - used in notebook cooling fans and instrument cooling systems.

For engineers reviewing the AH5773 datasheet, AH5773 pinout, AH5773 application, or AH5773 equivalent, key selection criteria include its dual-package availability (U-DFN2020-6 and MSOP-8EP), standby current <100 µA, over-voltage shutdown threshold (19–23 V), thermal shutdown at +170°C, and FG open-drain tach output synchronized to magnetic change frequency.

Technical Context

The AH5773 implements a closed-loop commutation system where the on-board Hall-effect sensor (BOP = 5–35 G, BRP = −35 to −5 G) detects rotor position to control the full-bridge driver via soft-switching logic (tSW = 200 µs typ.), minimizing EMI and audible noise. Its control block integrates dynamic offset cancellation, temperature/voltage-compensated references, and lock-detect timing (tON = 420 ms).

Power management includes three independent protections: over-voltage shutdown (VOV_TH = 19–23 V, VOV_RLTH = 18–22 V), thermal shutdown (TJ_SDN_TH = +170°C, hysteresis = +25°C), and rotor lock detection with automatic re-start. Standby mode activates when PWM is held low >65 ms, reducing IDD to <100 µA while preserving quick-start capability.

Key Specifications

Pinout & Package

The AH5773 is offered in two thermally enhanced packages: U-DFN2020-6 (2.0 mm × 2.0 mm, 0.65 mm height) and MSOP-8EP (3.0 mm × 3.0 mm, 1.0 mm height), both featuring exposed thermal pads for PCB-level heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXBM5212 and A4964, the AH5773 uniquely combines Hall sensor, soft-switching H-bridge, and sub-100 µA standby in a 2 mm × 2 mm DFN - making it optimal for cost-sensitive, noise-critical, and size-constrained 5–12 V cooling applications.

Availability

AH5773 is available at Aetrix Electronics and suitable for notebook cooling fans, instrumentation cooling systems, 5V/12V BLDC fans, and medium-voltage low-power motor control requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AH5773 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

Diodes Incorporated is a global manufacturer of high-performance discrete semiconductors and ICs, specializing in power management, signal integrity, and precision analog solutions for industrial, computing, and consumer markets.

The AH5773 belongs to Diodes' motor driver product line, engineered specifically for compact, low-noise, single-phase BLDC fan control - emphasizing integration, EMI reduction, and thermal resilience in space-constrained thermal management systems.

FAQ

What is the minimum PWM duty ratio required to start a motor with the AH5773?

At nominal 12 V supply, typical minimum start-up PWM duty is 20–45%, depending on motor inertia and load. Lower VDD increases required duty; minimum running duty drops to 10–25%. These values assume proper magnetic flux density (>±70 G) at the Hall sensor location per datasheet Note 17.

How does the AH5773 handle rotor lock conditions?

It detects lock via stalled commutation timing (t_ON = 420 ms), shuts down outputs, and automatically re-starts when rotation resumes. The t_OFF timer clears after PWM remains low >65 ms - enabling fast recovery without external reset circuitry.

Can the AH5773 operate from a 3 V supply?

Yes - it functions across 2.4 V to 18 V. At 3 V, R_DS(ON) rises to 1.37–2.4 Ω and output current capability decreases; ensure motor startup torque and speed meet requirements under low-voltage conditions.

What is the purpose of the exposed thermal pad in both packages?

The exposed pad provides primary thermal conduction path from die to PCB. For MSOP-8EP, four thermal vias to inner ground plane are recommended; for U-DFN2020-6, two vias suffice. Proper pad soldering improves power dissipation by up to 2.2 W (MSOP) or 1.23 W (DFN) at 25°C ambient.