STMicroelectronics ULN2802A Darlington Transistor Array, 18-Pin DIP

The STMicroelectronics ULN2802A is a high-performance, eight-channel Darlington transistor array housed in a through-hole 18-pin DIP (Dual In-line Package). This integrated circuit is engineered to drive high-current loads, making it an essential component for interfacing low-power logic circuits with motors, relays, solenoids, and other inductive devices.

Each of the eight Darlington pairs features a common emitter configuration and includes integral suppression diodes, which are crucial for protecting the transistors from voltage spikes generated by inductive loads when they are switched off. This built-in protection enhances the reliability and longevity of both the driver and the connected components.

The array boasts a robust output capability, with each channel rated for a continuous collector current of 500mA and a peak current of 600mA. It can withstand output voltages of up to 50V in the off state, providing a substantial safety margin for various applications. To simplify interfacing with different logic families, the ULN2802A incorporates a 10.5Kohm input resistor and a zener diode network optimised for 14V to 25V PMOS logic.

Key Features & Design Benefits:

• Simplified Board Layout: Inputs and outputs are pinned on opposite sides of the package, which greatly simplifies PCB routing and reduces layout complexity.
• High Current Capability: Outputs can be paralleled to achieve a higher total current drive, offering design flexibility for more demanding loads.
• Integrated Protection: The inclusion of integral clamp diodes eliminates the need for external diodes when driving inductive loads, saving board space and component cost.
• High DC Current Gain: With a current gain (hFE) of 1000, the array provides excellent signal amplification from low-current control signals.

Technical Specifications:

• Package: 18-pin DIP (Dual In-line)