Diodes Incorporated AH1895-FA-7

Overview

AH1895-FA-7 from Diodes Incorporated is a medium-sensitivity, micropower omnipolar Hall-effect switch IC in X1-DFN1216-4 package, operating from 1.6V to 3.6V with 4.3µA average supply current at 1.85V, BOP of ±40–80 Gauss, and hysteresis of 5–10 Gauss - used for lid, cover, and position sensing in portable electronics.

For engineers reviewing the AH1895-FA-7 datasheet, AH1895-FA-7 pinout, AH1895-FA-7 application, or AH1895-FA-7 equivalent, this page delivers verified magnetic thresholds, low-power hibernating clocking behavior, NC pin handling guidance, and package-specific PCB layout constraints - critical for battery-powered proximity detection designs.

Technical Context

The AH1895 employs chopper-stabilized architecture to suppress offset drift across temperature (−40°C to +85°C), delivering stable BOP/Brp switching points with <10 Gauss hysteresis and minimal thermal shift. Its hibernating clock system cycles between awake (100µs) and sleep (≈100ms) states to achieve sub-5µA average current draw.

Omnipolar operation enables activation by either north or south magnetic pole perpendicular to the package top surface; output is open-drain, actively pulled low when B exceeds BOP, and floats high (internally pulled up/down) when inactive - requiring no external resistors.

Key Specifications

Pinout & Package

Package: X1-DFN1216-4 (1.2 × 1.6 × 0.5 mm, 0.65 mm pitch, bottom-side sensor location). Pin 3 is NC (not internally connected); may be left floating or tied to GND per layout requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with A3263LUA-T and US1881EUA-ABA-000-SP, the AH1895-FA-7 uniquely combines sub-5µA operation, 1.6V start-up, and X1-DFN1216-4 miniaturization - making it the only viable choice for space- and energy-constrained lid/cover detection where magnet strength and PCB area are tightly constrained.

Availability

AH1895-FA-7 is available at Aetrix Electronics and suitable for cellular phone lid detection, tablet holster sensing, and portable PC display switching requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for AH1895-FA-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, low-power solutions for consumer, computing, and industrial markets.

The AH1895 belongs to Diodes' Hall-effect sensor product line, engineered specifically for ultra-low-power, contactless position sensing in battery-operated portable devices - emphasizing magnetic consistency, small footprint, and ease of integration.

FAQ

What is the magnetic polarity requirement for AH1895-FA-7 activation?

The AH1895-FA-7 is an omnipolar switch: it activates with either a north or south magnetic pole oriented perpendicular to the top surface of the X1-DFN1216-4 package. The operate point is +40 to +80 Gauss for south pole and −40 to −80 Gauss for north pole - enabling flexible magnet placement without polarity alignment.

Can Pin 3 (NC) be used as a thermal pad or grounded?

Yes - Pin 3 is a no-connect terminal with no internal bond wire. It may be left unconnected or tied to GND to improve thermal dissipation and mechanical stability. Diodes Incorporated's recommended PCB layout treats this pad as an exposed thermal slug, and grounding it enhances heat transfer to the board.

How does the hibernating clock affect response time in real-world use?

The AH1895-FA-7 wakes every ≈100ms (Tperiod), remains active for 50–100µs (Tawake), then returns to sleep. This yields 0.1% duty cycle and 4.3µA avg. current. For lid detection, latency is bounded by Tperiod - so worst-case response is 100ms, sufficient for human-speed interactions like opening a clamshell.

Is an external decoupling capacitor mandatory for stable operation?

Yes - a 100nF ceramic capacitor is required between VDD and GND, placed as close as possible to Pins 2 and 4. This stabilizes the internal regulator during wake cycles and improves RF noise immunity, especially in noisy environments like cellular handsets where GSM/UMTS burst transmission could otherwise induce false triggers.