ULN2803A STMicroelectronics TRANS 8NPN DARL 50V 0.5A 18DIP


The ULN2803A is a popular high-voltage, high-current Darlington transistor array manufactured by STMicroelectronics. Here is a detailed introduction to the ULN2803A:


1. Overview:

  • Manufacturer: STMicroelectronics
  • Part Number: ULN2803A
  • Type: 8-Channel NPN Darlington Transistor Array
  • Package: 18-pin DIP (Dual Inline Package)

2. Key Specifications:

  • Transistor Type: NPN Darlington Array
  • Voltage Rating: 50V (Maximum Collector-Emitter Voltage)
  • Current Rating: 500mA (Continuous Collector Current per Channel)
  • Number of Channels: 8
  • Package Type: 18-pin DIP package
  • Output Clamp Diodes for Inductive Load Driving: Includes built-in protection diodes for inductive loads
  • DataSheet

    ULN2803A PDF

3. Features and Applications:

  • Darlington Array: Integrated array of NPN Darlington transistors for high-current switching applications.
  • Voltage and Current Ratings: Designed for driving inductive or resistive loads at up to 50V and 500mA per channel.
  • Package Type: 18-pin DIP package for through-hole mounting on PCBs.
  • Built-in Diodes: Output clamp diodes provide protection for driving inductive loads.
  • Input/Output Common Pins: Simplifies interfacing with microcontrollers and other control devices.

4. Package Information:

  • DIP Package: Through-hole package suitable for mounting on standard PCBs.

5. Applications:

  • Stepper Motor Drivers: Used to control stepper motors in various applications.
  • Relay Drivers: Driving relays and solenoids in industrial and automation systems.
  • Lamp and LED Drivers: Controlling lamps and LEDs in lighting systems.
  • Motor Controls: Providing control for DC motors and other high-current devices.
  • Driver for Displays: Driving segments in LED displays and other display types.

6. Advantages:

  • High Current Capability: Each channel can handle up to 500mA of continuous current.
  • Multiple Channels: 8 NPN Darlington pairs in one package for driving multiple loads.
  • Built-in Protection Diodes: Integrated diodes for protecting against back EMF from inductive loads.
  • Interfacing Ease: Common input and output pins simplify control signal connections.

The ULN2803A from STMicroelectronics is a versatile 8-channel NPN Darlington transistor array designed for driving high-current loads such as relays, solenoids, stepper motors, and other inductive or resistive loads. With its high voltage and current ratings, built-in protection diodes, and multiple channels in a convenient DIP package, the ULN2803A is a popular choice for various industrial, automotive, and consumer electronic applications requiring reliable and efficient high-power switching capabilities.