Diodes Incorporated AH211Z4-BG1

Overview

AH211Z4-BG1 from BCD Semiconductor Manufacturing Limited is a two-phase Hall-effect latch IC with integrated frequency generator (FG) output, designed for electronic commutation in dual-coil brushless DC motors and fans. It features complementary open-collector outputs (DO/DOB), 400 mA average sink current per channel, ±30–60 Gauss magnetic operating point (Grade A), and operates from 3.5 V to 16 V across –20 °C to 85 °C.

For engineers reviewing the AH211Z4-BG1 datasheet, AH211Z4-BG1 pinout, AH211Z4-BG1 application in BLDC fan speed sensing or motor phase control, or AH211Z4-BG1 equivalent for FG-enabled Hall latches, this device delivers verified magnetic switching hysteresis, temperature-compensated sensitivity, and dual-output timing coordination in TO-94 packaging.

Technical Context

The AH211 integrates a Hall sensor, low-noise amplifier, Schmitt trigger with built-in hysteresis (60 G typical), and dual complementary open-collector drivers - enabling precise bipolar magnetic detection and robust load sinking. Its internal band-gap regulator ensures stable biasing across supply variations.

The FG output provides a pulse train synchronized to magnetic pole transitions, supporting revolution counting and RPM measurement. Magnetic thresholds (BOP = +5 to +60 G, BRP = –60 to –5 G) are temperature-compensated, and output saturation voltages remain ≤1.3 V at 400 mA sink load, ensuring reliable interface with TTL/CMOS logic and external pull-ups.

Key Specifications

Pinout & Package

Supplied in low-profile TO-94 (SIP-4L) package - 15.3 mm length, 4.98 mm width, 3.71 mm height - optimized for PCB mounting in compact fan housings and motor modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar two-phase Hall latch with FG output applications.

Compared with A3281LUA-T and US5881KSE-AAA-000-SP, AH211Z4-BG1 uniquely balances cost-effective dual-output commutation, integrated FG generation, and industrial-grade thermal performance in TO-94 - making it optimal for high-volume 12/24 V fan and blower designs where footprint and tachometer simplicity are critical.

Availability

AH211Z4-BG1 is available at Aetrix Electronics and suitable for brushless DC fan control, dual-coil motor commutation, and speed measurement systems requiring stable component supply, consistent magnetic threshold matching, and RoHS-compliant green packaging.

Supply support for AH211Z4-BG1 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 and foundry partner, specializing in high-voltage, high-current, and sensor interface solutions since 2003.

The AH211 belongs to BCD's magnetic sensor product line, engineered specifically for cost-sensitive, high-reliability BLDC motor and cooling fan applications - emphasizing integration, thermal stability, and ease of system-level implementation.

FAQ

What is the function of the FG pin on AH211Z4-BG1?

The FG (Frequency Generator) pin is an open-collector output that produces a pulse train synchronized to magnetic pole transitions - one pulse per pole pair. It sinks up to 20 mA at ≤30 V and is used for RPM measurement and tachometer feedback. Unlike DO/DOB, FG remains active regardless of polarity, providing unambiguous speed data without direction decoding.

Can AH211Z4-BG1 operate from a 5 V supply?

Yes - AH211Z4-BG1 is fully specified from 3.5 V to 16 V. At 5 V, it delivers 400 mA sink current per output with ≤1.3 V saturation voltage, and FG output remains functional with standard 220 Ω pull-up to 5 V. All magnetic thresholds and timing parameters remain valid within this range per datasheet Section 5.

How does the AH211Z4-BG1 handle temperature variation in magnetic sensitivity?

It incorporates an on-chip temperature compensation circuit that actively adjusts amplifier gain to maintain stable BOP (5–60 G) and BRP (–60 to –5 G) across –20 °C to 85 °C. Typical hysteresis remains 60 G over temperature, and Figures 9–10 in the datasheet confirm <±10% drift in switching points from –20 °C to 85 °C.

Is external reverse-polarity protection required when using AH211Z4-BG1?

Yes - the datasheet explicitly recommends a series diode (e.g., D1 in Figure 15) between VCC and the IC's supply input. Without it, reverse connection causes destructive current flow through internal drivers and motor coils. The diode introduces ~0.7 V drop but prevents burnout during field wiring errors or board rework.