Diodes Incorporated AH5792-ZG-7

Overview

AH5792-ZG-7 from Diodes Incorporated is a single-phase Hall-effect latch smart fan motor controller in SOT553 package, integrating full-bridge driver, Hall sensor amplifier, rotor lock detection, automatic self-restart, and open-drain tachometer (FG) output with 1/2 magnetic change frequency ratio. It operates from 1.8V to 5.0V supply, delivers up to 400mA peak output current, and targets ultra-thin cooling fans and micro-vibration motors.

For engineers reviewing the AH5792-ZG-7 datasheet, AH5792-ZG-7 pinout, AH5792-ZG-7 application, or AH5792-ZG-7 equivalent, key selection considerations include low-voltage startup capability (1.8V), integrated lock protection logic, FG timing relationship to magnetic transitions, and dual-package availability (SOT553 vs. SOT89-5L) affecting thermal performance and PCB footprint.

Technical Context

The AH5792 implements a Hall-sensor-based commutation control loop with full-bridge output stage driving a single-coil BLDC motor. Its logic block detects magnetic pole transitions (Bop = 10–50 G, Brp = –50 to –10 G) and generates complementary O1/O2 drive signals with configurable Ton/Toff duty ratio (RDR = 10).

Rotor lock detection triggers automatic restart by holding one output low while pulsing the other; FG output mirrors half the magnetic transition frequency and requires external pull-up. No external timing capacitor is needed-timing is internally derived from Hall input and motor dynamics.

Key Specifications

Pinout & Package

Package: SOT553 - 5-pin, low-profile surface-mount package (1.7 mm × 1.2 mm × 0.6 mm), optimized for space-constrained fan modules and thin-profile cooling assemblies.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-phase Hall-effect fan motor controller applications.

Compared with AH9485 and AH9486, the AH5792-ZG-7 uniquely combines FG output with 1/2 magnetic frequency ratio, SOT553 compactness, and guaranteed 1.8V startup-making it optimal for space- and voltage-constrained fan systems requiring deterministic tach feedback.

Availability

AH5792-ZG-7 is available at Aetrix Electronics and suitable for ultra-thin laptop cooling fans, smartphone haptic vibration motors, and industrial sensor-cooled enclosures requiring stable component supply, consistent thermal performance, and RoHS-compliant green packaging.

Supply support for AH5792-ZG-7 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 semiconductor company specializing in discrete, analog, and mixed-signal ICs, with design, manufacturing, and distribution infrastructure serving industrial, computing, consumer, and automotive markets.

The AH5792 belongs to Diodes' Smart Motor Control product line, engineered specifically for single-coil BLDC fan and micro-motor applications where integration, low-voltage operation, and stall-safe behavior are critical.

FAQ

What is the function of the NC pin on AH5792-ZG-7?

The NC (No Connection) pin on the AH5792-ZG-7 is internally unconnected and must remain electrically floating-no external connection or grounding is permitted. This pin exists for mechanical symmetry and package compatibility; connecting it may cause unpredictable behavior or violate absolute maximum ratings.

How does the FG output relate to motor speed and pole count?

The FG output toggles at exactly half the magnetic pole transition frequency (e.g., for an 8-pole motor rotating at 3000 RPM, magnetic transitions occur at 200 Hz, so FG outputs 100 Hz). This fixed 1/2 ratio enables direct RPM derivation without calibration: RPM = (FG frequency × 60) × 2 / pole count.

Can AH5792-ZG-7 drive a 12V fan?

No-AH5792-ZG-7 has an absolute maximum Vdd rating of 6 V and recommended operating range of 1.8–5.0 V. It is designed exclusively for low-voltage fans (3.3 V or 5 V systems). Driving a 12 V fan would exceed voltage limits and cause immediate device failure.

Why does AH5792-ZG-7 require external reverse polarity protection?

The AH5792 lacks internal reverse-voltage protection. If Vdd and Vss are swapped, internal junctions conduct destructively. Diodes Incorporated explicitly recommends adding a series Schottky diode (D1) on the Vdd line and a Zener clamp (Dz) between Vdd–Vss to prevent breakdown during accidental reverse connection.