a6276-led-driver

Important Note

This entire repo was AI created - including all of the data within. The intent was to A) help me with my personal electronics inventory; and B) see how I could use AI to make that process a bit easier. DO NOT TRUST!

A6276 - 16-Bit LED Driver IC

Details

• Location: Cabinet-3, Bin 39, Section A
• Category: Display Drivers
• Brand: Allegro Microsystems
• Part Number: A6276 / A6276EA
• Package: 24-DIP
• Quantity: 20
• Status: Available
• Price Range: $3.00-5.00 (estimated)
• Datasheet: A6276 Datasheet
• Product URL: https://www.allegromicro.com/en/products/led-drivers/led-display-drivers/a6276

Description

The A6276 is a specialized LED driver IC from Allegro Microsystems designed specifically for LED display applications. This BiCMOS device integrates a 16-bit CMOS shift register with accompanying data latches and 16 NPN output transistors, making it ideal for driving LED arrays and matrices. The serial data input capability allows for easy cascading of multiple devices to control larger LED displays while minimizing the number of control pins required from the microcontroller.

Specifications

Electrical Characteristics

• Supply Voltage: 5V typical
• Architecture: BiCMOS (Bipolar CMOS)
• Output Channels: 16 independent channels
• Output Type: NPN transistors for current sinking
• Data Interface: Serial shift register input
• Logic Family: CMOS compatible inputs

Physical Characteristics

• Package: 24-pin DIP (Dual In-line Package)
• Dimensions: 0.600” (15.24mm) width
• Pin Pitch: 0.100” (2.54mm)
• Operating Temperature: 0°C to +70°C (typical)

Key Features

• 16-bit CMOS shift register for serial data input
• 16 NPN output transistors for LED driving
• Data latches for stable output control
• Cascadable for larger displays
• BiCMOS architecture for efficient operation
• CMOS-compatible logic inputs

Pinout Diagram

    A6276 24-Pin DIP
    ┌─────────────────┐
OUT1│1              24│ VCC
OUT2│2              23│ OUT16
OUT3│3              22│ OUT15
OUT4│4              21│ OUT14
OUT5│5              20│ OUT13
OUT6│6              19│ OUT12
OUT7│7              18│ OUT11
OUT8│8              17│ OUT10
GND │9              16│ OUT9
CLK │10             15│ LATCH
DATA│11             14│ OUTPUT ENABLE
GND │12             13│ SERIAL OUT
    └─────────────────┘

Pin Descriptions

Pin	Name	Description
1-8	OUT1-OUT8	Output channels 1-8 (NPN collectors)
9,12	GND	Ground connections
10	CLK	Clock input for shift register
11	DATA	Serial data input
13	SERIAL OUT	Serial data output (for cascading)
14	OUTPUT ENABLE	Output enable control (active low)
15	LATCH	Latch enable for output register
16-23	OUT9-OUT16	Output channels 9-16 (NPN collectors)
24	VCC	Positive power supply

Applications

Common use cases for the A6276:

• LED matrix displays (dot matrix, character displays)
• Multi-digit 7-segment LED displays
• LED bar graphs and level indicators
• Decorative LED lighting arrays
• Industrial control panel indicators
• Automotive dashboard displays
• Signage and advertising displays

Circuit Examples

Basic LED Matrix Connection

MCU          A6276
VCC   ----   VCC (Pin 24)
GND   ----   GND (Pins 9, 12)
D2    ----   DATA (Pin 11)
D3    ----   CLK (Pin 10)
D4    ----   LATCH (Pin 15)
D5    ----   OUTPUT ENABLE (Pin 14)

Each OUT pin connects to LED cathodes
LED anodes connect to current limiting resistors and VCC

Cascading Multiple A6276s

MCU DATA ---- A6276 #1 DATA IN
A6276 #1 SERIAL OUT ---- A6276 #2 DATA IN
A6276 #2 SERIAL OUT ---- A6276 #3 DATA IN
(Common CLK, LATCH, and OUTPUT ENABLE signals)

Programming Examples

Arduino Control Example

#define DATA_PIN 2
#define CLOCK_PIN 3
#define LATCH_PIN 4
#define OE_PIN 5
 
void setup() {
  pinMode(DATA_PIN, OUTPUT);
  pinMode(CLOCK_PIN, OUTPUT);
  pinMode(LATCH_PIN, OUTPUT);
  pinMode(OE_PIN, OUTPUT);
  
  digitalWrite(OE_PIN, LOW); // Enable outputs
}
 
void sendData(uint16_t data) {
  digitalWrite(LATCH_PIN, LOW);
  
  for (int i = 15; i >= 0; i--) {
    digitalWrite(DATA_PIN, (data >> i) & 1);
    digitalWrite(CLOCK_PIN, HIGH);
    digitalWrite(CLOCK_PIN, LOW);
  }
  
  digitalWrite(LATCH_PIN, HIGH);
}
 
void loop() {
  sendData(0x5555); // Alternating pattern
  delay(500);
  sendData(0xAAAA); // Opposite pattern
  delay(500);
}

Technical Notes

Important considerations for the A6276:

• Current Limiting: Use appropriate current limiting resistors for LEDs
• Power Supply: Ensure adequate current capability for all active LEDs
• Heat Dissipation: Consider heat sinking for high-current applications
• Cascading: Serial output allows daisy-chaining multiple devices
• Timing: Follow datasheet timing requirements for reliable operation

Tags

led-driver, shift-register, display-driver, 16-bit, allegro, bicmos cabinet-3 bin-39 status-available

Notes

The A6276 is an excellent choice for LED display applications where you need to control multiple LEDs with minimal microcontroller pins. Having 20 of these ICs provides substantial capability for building large LED matrix displays or multiple smaller displays. The BiCMOS architecture offers good performance with reasonable power consumption, and the serial interface makes it easy to cascade multiple devices for larger displays. These drivers are particularly useful for projects requiring precise LED control with good current handling capability. The shift register design allows for efficient updating of display patterns while the output latches ensure stable display output.