Diodes Incorporated AH1903-FA-EVM

Overview

AH1903-FA-EVM from Diodes Incorporated is an evaluation module for the AH1903 high-sensitivity micropower Hall-effect switch IC, supporting configurable unipolar/omnipolar magnetic sensing with 4.3µA average supply current at 1.8V, 1.6–3.6V operating voltage range, and X1-DFN1216-4 package. It enables rapid validation of flip-cover detection, smart dock sensing, and contactless position switching in portable electronics.

For engineers reviewing the AH1903-FA-EVM datasheet, AH1903 pinout, AH1903 application, or AH1903 equivalent, this EVM provides hardware-level verification of SEL-pin-controlled magnetic mode selection, low-power hibernation timing, output switching thresholds (Bop = 33 G typ., Brp = 23 G typ.), and PCB layout compatibility with the X1-DFN1216-4 footprint.

Technical Context

The AH1903-FA-EVM implements a chopper-stabilized Hall sensor architecture with internal clock gating to achieve ultra-low power consumption. Its hibernating clocking system cycles between awake (100µs) and sleep (50ms) phases, delivering <4.3µA average current at 1.8V while maintaining valid output sampling after two complete awake periods.

Mode selection is controlled via the SEL pin: open/high configures unipolar operation (South-pole-only activation), while grounded SEL enables omnipolar detection (North or South pole). The output is open-drain, internally pulled low when active, with VOL = 0.2V max at 1mA sink current and 8kV HBM ESD protection on VDD, GND, and OUTPUT pins.

Key Specifications

Availability

AH1903-FA-EVM is available at Aetrix Electronics and suitable for smart cover detection, flip-phone lid sensing, and tablet docking applications requiring stable component supply and rapid prototyping support.

Supply support for AH1903-FA-EVM 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 discrete semiconductors and analog ICs, specializing in power management, signal integrity, and sensing solutions for high-efficiency, space-constrained electronics.

The AH1903 product line targets ultra-low-power magnetic position sensing in portable consumer devices, emphasizing micropower operation, flexible magnetic polarity selection, and minimal PCB footprint through DFN packaging.

FAQ

What is the purpose of the SEL pin on the AH1903-FA-EVM?

The SEL pin selects magnetic sensing mode: open or high enables unipolar operation (South-pole-only detection), while grounded SEL activates omnipolar mode (North or South pole detection). Internal 50kΩ pull-up ensures default unipolar behavior if left unconnected, eliminating need for external resistors.

How does the hibernating clocking system reduce power consumption?

The AH1903 alternates between 100µs awake periods (for magnetic sampling and output update) and ~50ms sleep intervals (deep standby). This duty cycle yields only 0.1% active time, achieving 4.3µA average current at 1.8V-critical for battery-powered cover-switch applications lasting years on a single charge.

Can the AH1903-FA-EVM operate reliably across temperature extremes?

Yes-the AH1903 maintains stable Bop (21–48 G) and Brp (9–38 G) over −40°C to +85°C, with chopper stabilization minimizing thermal drift. Typical hysteresis remains 10 G across temperature, ensuring consistent mechanical tolerance in clamshell hinges and sliding mechanisms under real-world thermal cycling.

What is the recommended decoupling capacitor for the AH1903-FA-EVM?

A 100nF ceramic capacitor is recommended between VDD and GND, placed as close as possible to the VDD pin. This stabilizes supply during wake-up transients and enhances RF noise immunity-particularly important in noisy mobile device environments with Bluetooth/WiFi coexistence.