A3144 Hall Effect Sensor Non-Contact Magnetic Detector Transistor IC (TO-92 Package)

Detect magnetic fields reliably with the A3144 Hall Effect Sensor IC. Operating on the principle of the Hall Effect, this non-contact digital magnetic switch triggers a crisp, low-active digital output whenever a magnetic field (South Pole) is detected. Packaged in a compact 3-pin TO-92 housing, the A3144 features an internal voltage regulator, reverse battery protection, a Hall voltage generator, and an open-collector output transistor. Capable of handling supply voltages from 4.5V to 24V DC, it is an industry-standard choice for rotational speed measurement (tachometers), door position sensing, brushless DC motor commutation, and wheel encoders with Arduino, Raspberry Pi, or ESP32.

( No Reviews )

₹ 8 ^{₹ 11}

Order From Whatsapp

Seller Electro Boat

Tags A3144 Hall Sensor A3144 Hall Effect IC Magnetic Sensor TO92 A3144 Digital Switch Speed Sensor IC RPM Tachometer Sensor Non Contact Magnetic Switch Arduino Hall Sensor

No Cancellation

No Returnable

Product Details :

The A3144 Hall Effect Sensor is a monolithic integrated circuit designed for reliable non-contact magnetic sensing. Built using bipolar semiconductor technology, the IC combines a voltage regulator, a Hall voltage element, a signal amplifier, a Schmitt trigger circuit, and an open-collector output transistor onto a single silicon chip.

When a permanent magnet or magnetic field of sufficient strength (South Pole) approaches the branded face of the A3144 package, the sensor's open-collector NPN transistor turns ON, pulling the output pin LOW (0V). When the magnetic field is removed, the transistor turns OFF, allowing an external pull-up resistor to bring the output signal high ( $V_{CC}$ ). Because the sensor is completely solid-state without moving mechanical contacts, it provides virtually infinite operating life, immune to mechanical wear, dust, moisture, and vibration.

Key Features and Benefits

Wide Operating Voltage Range: Functions across a broad supply range of $4.5 ext{V}$ to $24 ext{V DC}$ , making it directly compatible with $5 ext{V}$ logic microcontrollers as well as $12 ext{V}-24 ext{V}$ industrial PLC controllers.
Non-Contact Magnetic Sensing: Zero physical contact ensures frictionless detection, eliminating mechanical bounce and contact wear.
Internal Schmitt Trigger: Built-in hysteresis guarantees clean, bounce-free digital switching transitions even under weak or slowly changing magnetic fields.
Reverse Battery Protection: Integrated diode protection guards the IC against accidental supply voltage reversal.
High-Speed Switching Rate: Fast response time capable of switching at frequencies up to tens of kilohertz, ideal for high-speed motor RPM calculations.

Technical Specifications

Feature Component	Specification Details
Model Designation	A3144 (Allegro MicroSystems architecture)
Package Type	3-Pin Through-Hole TO-92UA
Operating Voltage ( $V_{CC}$ )	$4.5 ext{V DC} - 24 ext{V DC}$
Supply Current	$pprox 4.0 ext{ mA} - 9.0 ext{ mA}$
Output Type	Open-Collector NPN Digital Output (Active LOW)
Output Sink Current ( $I_{SINK}$ )	Max $25 ext{ mA}$
Magnetic Operate Point ( $B_{OP}$ )	$350 ext{ Gauss}$ (Typical)
Magnetic Release Point ( $B_{RP}$ )	$100 ext{ Gauss}$ (Typical)
Operating Temperature	$-40^circ ext{C to } +85^circ ext{C}$

Pinout Guide

Holding the TO-92 package with the flat printed side facing you and pins pointing downwards:

Pin 1 ( $V_{CC}$ / Left Pin): Supply Voltage Positive ( $+4.5 ext{V}$ to $+24 ext{V DC}$ ).
Pin 2 (GND / Middle Pin): Power Ground ( $0 ext{V}$ ).
Pin 3 (OUT / Right Pin): Open-Collector Signal Output (Requires an external $10 ext{k}Omega$ pull-up resistor to $V_{CC}$ or internal microcontroller pull-up enabled).

PULL-UP RESISTOR REQUIREMENT: Because the A3144 has an open-collector output stage, you MUST connect a $10 ext{k}Omega$ resistor between the Output Pin (Pin 3) and $V_{CC}$ (Pin 1) for the output voltage to switch cleanly between $0 ext{V}$ and $5 ext{V}$ .

Arduino Quick-Start Code Example (RPM / Pulse Counter)

C++
// A3144 Hall Effect Sensor Test Code
// Pin 3 (OUT) connected to Arduino Digital Pin 2 (Interrupt 0)
// A 10k Ohm resistor is connected between Pin 3 and 5V VCC

const int HALL_PIN = 2;
const int LED_PIN = 13; // Onboard LED

volatile unsigned long pulseCount = 0;

void countPulse() {
  pulseCount++;
}

void setup() {
  Serial.begin(9600);
  pinMode(HALL_PIN, INPUT_PULLUP); // Enable internal pull-up resistor
  pinMode(LED_PIN, OUTPUT);
  
  // Trigger interrupt on FALLING edge (when magnet arrives, output goes LOW)
  attachInterrupt(digitalPinToInterrupt(HALL_PIN), countPulse, FALLING);
  Serial.println("A3144 Hall Effect Sensor Test Initialized.");
}

void loop() {
  // Read state to toggle indicator LED
  int sensorState = digitalRead(HALL_PIN);
  digitalWrite(LED_PIN, (sensorState == LOW) ? HIGH : LOW);

  Serial.print("Total Magnet Detections: ");
  Serial.println(pulseCount);
  delay(500);
}

Applications

Rotational Speed Measurement (Tachometers): Measuring shaft RPM on motors, bicycle wheels, CNC spindles, and wind turbines.
Proximity & Door Position Sensing: Non-contact limit switching for CNC axes, 3D printers, and security alarm door sensors.
Brushless DC Motor (BLDC) Commutation: Rotor position sensing in small electric motors and cooling fans.
Smart Flow Meters: Water and fluid flow sensors using magnetic impeller wheels.