Overview
The ULN2803A, produced by STMicroelectronics, is a high-voltage, high-current Darlington transistor array. This device consists of eight NPN Darlington pairs, each capable of handling high-voltage outputs and featuring common-emitter configurations with integral suppression diodes for inductive loads. The ULN2803A is designed to simplify interfacing with standard logic families, particularly 5 V TTL and CMOS, thanks to its 2.7 kΩ input resistor. It is widely used in various applications requiring high current drive capabilities and is supplied in an 18-lead plastic DIP package with a convenient input-opposite-output pinout to ease board layout.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Output Voltage | 50 | V |
| Continuous Collector Current | 500 | mA |
| Peak Load Current | 600 | mA |
| Input Voltage (for 5 V TTL/CMOS) | 30 | V |
| Input Resistor | 2.7 kΩ | |
| Operating Ambient Temperature Range | -20 to 85 | °C |
| Storage Temperature Range | -55 to 150 | °C |
| Junction Temperature | -20 to 150 | °C |
| Package Style | DIP-18 | |
| Mounting Method | Through Hole |
Key Features
- Eight Darlington transistors with common emitters
- Output current up to 500 mA (continuous) and 600 mA (peak)
- Output voltage up to 50 V
- Integral suppression diodes for inductive loads
- Versions for all popular logic families (ULN2803A specifically for 5 V TTL and CMOS)
- Outputs can be paralleled for higher current capability
- Inputs pinned opposite outputs to simplify board layout
- 2.7 kΩ series base resistor for each Darlington pair
Applications
- Relay drivers
- Solenoid drivers
- Lamp drivers
- Display drivers (LED and gas discharge)
- Line drivers and logic buffers
- Factory automation and control
- Building automation
- Appliances
- IP network camera
- HVAC valve and actuator control
- Stepper motor driving
Q & A
- What is the ULN2803A?
The ULN2803A is a high-voltage, high-current Darlington transistor array produced by STMicroelectronics.
- How many Darlington transistors does the ULN2803A contain?
The ULN2803A contains eight NPN Darlington pairs.
- What is the maximum output voltage of the ULN2803A?
The maximum output voltage is 50 V.
- What is the continuous collector current rating of the ULN2803A?
The continuous collector current rating is 500 mA.
- Can the outputs of the ULN2803A be paralleled?
- What type of logic families is the ULN2803A compatible with?
The ULN2803A is specifically designed for 5 V TTL and CMOS logic families.
- What is the purpose of the integral suppression diodes in the ULN2803A?
The integral suppression diodes are used to suppress the kickback voltage from inductive loads.
- In what package is the ULN2803A supplied?
The ULN2803A is supplied in an 18-lead plastic DIP package.
- What is the operating ambient temperature range of the ULN2803A?
The operating ambient temperature range is -20 to 85 °C.
- What are some common applications of the ULN2803A?
Common applications include relay drivers, solenoid drivers, lamp drivers, and stepper motor driving, among others.
