Diodes Incorporated AH3722Q-P-A

Overview

AH3722Q-P-A from Diodes Incorporated is an AEC-Q100 Grade 0 qualified automotive Hall-effect latch IC designed for brushless DC motor commutation and angular position sensing. It operates from 3.0V to 28V, features bipolar latching (South pole ON / North pole OFF), delivers BOP = 10–40 G and BRP = –40 to –10 G, and supports –40°C to +150°C ambient operation in SC59 package.

For engineers reviewing the AH3722Q-P-A datasheet, AH3722Q-P-A pinout, AH3722Q-P-A application, or AH3722Q-P-A equivalent, key selection criteria include magnetic sensitivity tolerance across temperature, open-drain output current limit (30–55 mA), chopper-stabilized offset cancellation, reverse supply protection (–18 V), and package-specific pole orientation requirements.

Technical Context

The AH3722Q-P-A uses a chopper-stabilized architecture with dynamic offset cancellation to minimize switch-point drift over temperature and supply voltage. Its internal bandgap regulator supplies temperature-compensated bias to analog blocks, enabling stable BOP/BRP performance from –40°C to +150°C and 3.0V–28V VDD.

Magnetic response is polarity- and package-dependent: for SC59, South pole must approach the non-marking side to activate; SOT23 (Type S) and SIP-3 variants require South pole on the marking side. Output latching behavior holds state until flux reverses beyond BRP, with 20–80 G hysteresis (BHY).

Key Specifications

Pinout & Package

Package: SC59 - surface-mount, 3-pin, lead-free, RoHS-compliant package with standard footprint and thermal profile for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with A1220LUA-T and US1881EUA-ABA-001-SP, the AH3722Q-P-A uniquely combines wide 3–28 V operation, integrated reverse-voltage and zener protection, and full Grade 0 temperature capability-making it the only option qualified for direct integration into high-reliability, high-stress automotive powertrain sensors.

Availability

AH3722Q-P-A is available at Aetrix Electronics and suitable for brushless DC motor control, engine RPM sensing, throttle position monitoring, and transmission encoder applications requiring stable component supply across automotive production lifecycles.

Supply support for AH3722Q-P-A 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 manufacturer specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, and computing markets.

The AH372XQ series belongs to Diodes' automotive-qualified Hall-effect sensor product line, engineered specifically for robust, high-temperature position and speed sensing in safety-critical vehicle subsystems.

FAQ

What is the magnetic polarity requirement for AH3722Q-P-A activation in SC59 package?

The AH3722Q-P-A in SC59 package requires a South pole applied to the non-part-marking side to turn the output ON. This is opposite to SOT23 (Type S) and SIP-3 variants, which require South pole on the marking side. The polarity orientation is fixed by package geometry and cannot be reversed via configuration.

Does AH3722Q-P-A require an external bypass capacitor?

Yes - a 10 nF to 100 nF ceramic capacitor (CIN) between VDD and GND is mandatory for power stabilization and RF noise immunity. Without it, the device may exhibit erratic switching or increased susceptibility to conducted EMI in automotive environments.

Can AH3722Q-P-A operate from a 3.3 V supply in automotive systems?

Yes - the 3.0 V minimum supply allows direct interface with 3.3 V microcontrollers, but note that BOP/BRP sensitivity decreases slightly at lower VDD. At 3.3 V, typical BOP is ~15 G (vs. 25 G at 12 V), requiring stronger magnets or closer air gaps in low-voltage designs.

How does the output current limit protect the AH3722Q-P-A?

The internal 30–55 mA output current limit actively restricts sink current during short-circuit or excessive load conditions. This prevents thermal runaway and bond-wire failure, enabling safe operation even with RL ≤ 1 kΩ and eliminates need for external current-limiting resistors in most designs.