Diodes Incorporated AH277AZ4-CG1

Overview

AH277AZ4-CG1 from BCD Semiconductor Manufacturing Limited is a complementary-output Hall-effect latch IC designed for electronic commutation in brushless DC motors. It integrates a Hall sensor, amplifier, Schmitt trigger with hysteresis, temperature compensation, band-gap regulator, and dual open-collector drivers-each rated for 400 mA average sink current. Operates from 3.5 V to 16 V across –20°C to +85°C in TO-94 (SIP-4L) package, enabling precise magnetic polarity detection in motor rotor position sensing.

For engineers reviewing the AH277AZ4-CG1 datasheet, AH277AZ4-CG1 pinout, AH277AZ4-CG1 application, or AH277AZ4-CG1 equivalent, key selection criteria include magnetic operating point (BOP = 10–50 G), release point (BRP = –50 to –10 G), complementary output timing (tr ≤ 10 µs, tf ≤ 1.5 µs), reverse supply protection (–20 V), and green RoHS-compliant packaging.

Technical Context

The AH277AZ4-CG1 implements a bipolar latching Hall sensor architecture with built-in hysteresis (BHYS = 60 G) to reject noise during magnetic field transitions. Its dual open-collector outputs (DO and DOB) provide complementary logic states-DO low / DOB high when B > BOP, and DO high / DOB low when B < BRP-enabling direct drive of external power transistors in BLDC half-bridge configurations.

Internal temperature compensation maintains stable BOP/BRP over –20°C to +85°C ambient, while the on-chip band-gap regulator ensures consistent biasing across supply voltages from 3.5 V to 16 V. The device features reversed supply voltage protection and ESD robustness (300 V MM, 2000 V HBM), supporting reliable operation in electrically noisy motor control environments.

Key Specifications

Pinout & Package

Package: TO-94 (SIP-4L), low-profile 4-pin single-in-line package with Hall element centered under die pad; lead-free and green-compliant (G1 suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Hall-effect latch applications.

Compared with A3291LUA-T and US5881KSE-ABA-000-RE, AH277AZ4-CG1 uniquely delivers 400 mA complementary sinking in TO-94 with integrated reverse-voltage protection-making it optimal for cost-sensitive, high-current BLDC commutation where board space and external component count are constrained.

Availability

AH277AZ4-CG1 is available at Aetrix Electronics and suitable for brushless DC motor commutation, DC fan control, revolution counting, and speed measurement requiring stable component supply, green RoHS compliance, and long-term industrial availability.

Supply support for AH277AZ4-CG1 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

BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and mixed-signal IC designer specializing in power management, motor control, and sensor interface solutions for industrial and consumer markets.

AH277AZ4-CG1 belongs to BCD's Hall-effect sensor product line, engineered specifically for robust, low-cost electronic commutation in BLDC motors and fans-emphasizing latch reliability, thermal stability, and system-level integration.

FAQ

What is the magnetic sensitivity grade of AH277AZ4-CG1?

AH277AZ4-CG1 is Grade A, with an operating point (BOP) of 10–50 Gauss and release point (BRP) of –50 to –10 Gauss at 25°C. This grade provides optimal hysteresis (60 G) for reliable switching in moderate-strength magnetic fields typical of ferrite or NdFeB rotor assemblies in 2–4 pole BLDC motors.

Can AH277AZ4-CG1 drive MOSFET gates directly?

Yes-its 400 mA average sink current and 0.35 V saturation voltage at 400 mA allow direct drive of N-channel MOSFET gate resistors ≤10 Ω. For higher gate charge loads or faster turn-off, a pull-up resistor (e.g., 10 kΩ to VCC) is recommended to ensure DO/DOB rise time remains ≤10 µs under capacitive loading.

Does AH277AZ4-CG1 require an external decoupling capacitor?

Yes-a 0.1 µF ceramic capacitor between VCC and GND, placed within 5 mm of the TO-94 pins, is required to suppress supply transients induced by motor coil switching. The internal band-gap regulator improves PSRR but does not eliminate need for local high-frequency bypassing.

How does reversed supply voltage protection work in AH277AZ4-CG1?

An internal series diode blocks reverse current flow into the chip when VCC is connected with negative polarity. It protects internal circuits up to –20 V, but does not protect external components (e.g., motor coils). External reverse-polarity protection diodes remain necessary on the system power rail if coil-side reverse conduction must be prevented.