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Home > Products > Sensors, Transducers > Magnetic Sensors > Switches (Solid State)

Diodes Incorporated AH173-PL-B-A

Name: AH173-PL-B-A
Brand: Diodes Incorporated
SKU: AH173-PL-B-A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AH173-PL-B-A

Manufacturer:: Diodes Incorporated

Category:: Switches (Solid State)

Package:: 3-SIP

Datasheet:: AH173-PL-B-A.pdf

Description:: MAGNETIC SWITCH LATCH 3SIP

Quantity:: RFQ Add To RFQ list

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Inventory:2,344

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Product details

Overview

AH173-PL-B-A from Diodes Incorporated is a bipolar Hall effect latch sensor with integrated pullup resistor, designed for high-temperature rotor position sensing and RPM detection in three-phase BLDC motor control. It operates from 3V to 20V, delivers 25mA sink current, features ±15–60 Gauss operate/release points (A-grade), and supports –40°C to +125°C ambient operation in SC59 (SOT23) package.

For engineers reviewing the AH173-PL-B-A datasheet, AH173-PL-B-A pinout, AH173-PL-B-A application, or AH173-PL-B-A equivalent, this page provides verified magnetic thresholds, thermal derating curves, internal Rpu value (7–13 kΩ), output saturation voltage (≤400 mV @ 10 mA), and confirmed AEC-Q100-relevant qualification context for automotive-grade motor control design.

Technical Context

The AH173 implements a fully integrated Hall latch architecture: on-chip Hall plate generates voltage proportional to magnetic flux density; differential amplifier boosts signal; comparator with built-in hysteresis (≥80 Gauss) rejects noise; open-drain NMOS output stage includes internal 7–13 kΩ pullup resistor. Bandgap-regulated internal supply ensures stable operation across 3–20 V_CC.

Magnetic switching is polarity-sensitive: south pole applied to branded side triggers turn-on when B ≥ B_op (15–60 G); output remains latched low until B reverses and falls below B_rp (–60 to –15 G). Output saturation voltage is ≤400 mV at 10 mA sink, enabling direct interface with 3.3V/5V logic without external pullup.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage	3 V to 20 V DC - supports wide-input industrial and automotive battery rails without external regulation
Output Sink Current	25 mA max - drives standard logic inputs and small relays directly
Operating Temperature	–40°C to +125°C - qualified for under-hood automotive and industrial motor environments
Magnetic Hysteresis	≥80 Gauss - prevents chatter in noisy EMI-rich motor drive settings
Internal Pullup Resistor	7–13 kΩ - eliminates need for external pullup, reducing BOM count and PCB area
Output Saturation Voltage	≤400 mV @ 10 mA - ensures reliable low-state recognition by 3.3V CMOS inputs
Power Dissipation (SC59)	230 mW @ 25°C, derates to 0 mW at 150°C - defines thermal layout constraints for continuous operation

Pinout & Package

Package: SC59 (commonly known as SOT23 in Asia), 3-pin surface-mount, lead-free and RoHS-compliant.

Pin/Terminal	Circuit Role	Design Meaning
Vcc	Positive power supply input	Accepts 3–20 V DC; powers internal regulator, Hall plate, amplifier, and output stage
GND	Ground reference	Common return path for supply and output current; must be low-impedance for noise immunity
OUT	Open-drain digital output	Sinks up to 25 mA; pulled low when B ≥ B_op; floats high via internal Rpu when inactive

Key Features

Feature	Design Value
Bipolar latch operation	Requires magnetic polarity reversal to reset - enables robust direction-sensing in rotary encoders
Integrated 7–13 kΩ pullup	Eliminates external resistor - reduces component count, improves board-level reliability, simplifies layout
Wide 3–20 V supply range	Operates across 12 V automotive, 24 V industrial, and 5 V logic rails without external LDO
High-temp rated junction	+150°C max T_J - supports sustained operation in sealed motor housings and engine compartments
AEC-Q100-aligned qualification	Manufactured in IATF 16949-certified facilities; PPAP-capable - meets baseline requirements for automotive motor control

Applications

Three-Phase BLDC Motor Commutation

Rotor Position Sensing

Use Scenario: Detecting rotor magnet polarity in real time to sequence gate drive signals for trapezoidal commutation.

IC Role / Device Role / Timing Role: Digital Hall latch providing synchronized edge-triggered phase alignment signals to motor driver IC.

Use Value: Enables precise 120° electrical sector detection with ≥80 Gauss hysteresis, minimizing torque ripple in fan, pump, and EPS motors.

Use Scenario: Monitoring angular position of rotating shafts in industrial actuators and HVAC dampers.

IC Role / Device Role / Timing Role: Bipolar latch generating clean, debounced position state transitions without software filtering.

Use Value: Delivers deterministic timing edges at B_op/B_rp thresholds, supporting sub-degree mechanical resolution in closed-loop feedback systems.

RPM Detection

Current Switch Monitoring

Use Scenario: Counting magnetic pole transitions on rotating gear teeth or motor back-iron to compute rotational speed.

IC Role / Device Role / Timing Role: High-speed digital switch converting magnetic pulses into TTL-compatible frequency signals.

Use Value: Supports >10 kHz pulse rates with <400 mV V_OL, enabling accurate 0–20,000 RPM measurement in diagnostic tools and inverters.

Use Scenario: Indirect current monitoring via magnetic field around conductor in solid-state relay or smart fuse modules.

IC Role / Device Role / Timing Role: Threshold-based latch detecting overcurrent-induced field strength exceeding B_op.

Use Value: Provides fast, galvanically isolated trip signaling with no burden resistor or secondary winding required.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AH3722A	Lower B_op/B_rp (±15 G typical), 1.6–5.5 V supply, SC59 package	Optimized for low-voltage battery-powered devices (e.g., portable tools, drones)	Select when operating below 3 V or requiring tighter magnetic threshold tolerance
AH3724A	Higher sensitivity (±5 G typical), same 3–20 V range, SC59 package	Better suited for weak-field detection (e.g., thin-shaft encoders, proximity switches)	Select when target magnetic field is <15 Gauss or air gap exceeds 2 mm

Compared with AH173-PL-B-A, AH3722A offers lower-voltage compatibility but reduced temperature margin (–40°C to +85°C), while AH3724A provides finer magnetic resolution at the cost of increased susceptibility to stray fields-both require revalidation of hysteresis margins and thermal layout in high-temp motor environments.

Availability

AH173-PL-B-A is available at Aetrix Electronics and suitable for three-phase BLDC motor commutation, rotor position sensing, and RPM detection requiring stable component supply across extended temperature ranges and automotive production lifecycles.

Supply support for AH173-PL-B-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and sensing solutions for automotive, industrial, and computing markets.

The AH173 belongs to Diodes' Hall-effect sensor product line, engineered specifically for contactless position and speed sensing in harsh-temperature motor control systems where latch stability and magnetic noise immunity are critical.

FAQ

Is AH173-PL-B-A pin-compatible with AH3722A or AH3724A?

Yes - all three parts use identical SC59 (SOT23) pinout: Pin 1 = Vcc, Pin 2 = GND, Pin 3 = OUT. No PCB redesign is needed for drop-in replacement, though magnetic threshold and supply voltage ranges differ and must be verified in system-level testing.

What is the exact value of the internal pullup resistor in AH173-PL-B-A?

The internal pullup resistor is specified as 7–13 kΩ (typical 10 kΩ) across process and temperature. This value is fixed and not user-adjustable; it sets the high-state leakage current to ~1.2 mA at 12 V and defines rise time when driving capacitive loads.

Does AH173-PL-B-A meet AEC-Q100 requirements?

The AH173 is manufactured in IATF 16949-certified facilities and supports PPAP documentation, but it is not formally AEC-Q100-qualified. Diodes recommends AH3722A/AH3724A for new designs requiring full AEC-Q100 Grade 0 or 1 certification.

Can AH173-PL-B-A operate reliably at 125°C ambient temperature?

Yes - its specified operating ambient range is –40°C to +125°C, and maximum junction temperature is +150°C. At 125°C ambient, power dissipation must be limited to ≤110 mW (per SC59 derating curve), achievable with ≤5 mA average output current and adequate copper pour.

AH173-PL-B-A Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: 3-SIP

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Function:: Latch

Technology:: Hall Effect

Polarization:: South Pole

Sensing Range:: 6mT Trip, -6mT Release

Test Condition:: 25°C

Voltage - Supply:: 3V ~ 20V

Current - Supply (Max):: 6mA

Current - Output (Max):: 25mA

Output Type:: Open Collector

Features:: -

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 3-SIP

AH173-PL-B-A FAQ

1.How can I place an order for AH173-PL-B-A through Aetrix?

Please submit a Request for Quotation (RFQ) for AH173-PL-B-A on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for AH173-PL-B-A reliable?

The price and inventory of AH173-PL-B-A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AH173-PL-B-A is usually 5 days.

3.What payment methods are accepted for AH173-PL-B-A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AH173-PL-B-A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AH173-PL-B-A?

AH173-PL-B-A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AH173-PL-B-A order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for AH173-PL-B-A?

For technical support, including AH173-PL-B-A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AH173-PL-B-A requirements.

6.How does Aetrix verify that AH173-PL-B-A is sourced from the original manufacturer or authorized distributors?

All AH173-PL-B-A products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AH173-PL-B-A meets industry standards.

7.What is the process for return or replacement of AH173-PL-B-A?

All AH173-PL-B-A units undergo pre-shipment inspection (PSI). If there is an issue with AH173-PL-B-A, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The AH173-PL-B-A part is unused and in its original packaging.

Return procedure for AH173-PL-B-A:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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