ULN2802A

Overview

The ULN2802A is an octal Darlington transistor array manufactured by STMicroelectronics. It integrates eight NPN Darlington pairs with common emitters and includes integral suppression diodes for driving inductive loads. The device features a 10.5 kΩ input resistor and a Zener diode, specifically designed for interfacing with 14-25 V PMOS logic families. Key electrical parameters include a maximum collector-emitter voltage (VCEO) of 50 V and a continuous DC collector current of 500 mA per channel. Outputs can be paralleled to increase current capability. The component is housed in an 18-lead plastic DIP package suitable for through-hole mounting and operates within a temperature range of -20°C to +85°C.

Feature Summary

• Integrates eight NPN Darlington transistors with common emitters
• Includes integral suppression diodes for inductive load protection
• Features a 10.5 kΩ input resistor and Zener diode for 14-25 V PMOS compatibility
• Utilizes an input-opposite-output pinout to simplify board layout

Applications

• Interfacing with 14-25 V PMOS logic families
• Driving inductive loads such as relays or solenoids
• General purpose switching applications requiring high current gain

Procurement Notes

Verify the manufacturer part number against official STMicroelectronics documentation to ensure authenticity. Confirm that the specific revision matches the required 10.5 kΩ input resistor and Zener diode configuration for PMOS compatibility. Check RoHS compliance status via the manufacturer's official channels. Ensure the package type corresponds to the required 18-lead PDIP form factor for your design.

Selection Notes

Select the ULN2802A when interfacing with 14-25 V PMOS logic families due to its specific 10.5 kΩ input resistor and Zener diode. Choose this variant over other ULN280x series members if the application requires this specific voltage range and logic interface. Consider paralleling outputs if the load current exceeds the 500 mA continuous rating per channel. Ensure the operating environment stays within the specified -20°C to +85°C temperature range.

Part Context

The ULN2802A belongs to the ULN280x family of octal Darlington arrays from STMicroelectronics. This family includes four variants: ULN2801A (general purpose with current limit resistor), ULN2802A (14-25 V PMOS compatible), ULN2803A (5 V TTL/CMOS compatible), and ULN2804A (6-15 V CMOS compatible). All share the same 18-lead PDIP package and internal Darlington structure but differ in input resistance and protection components to suit different logic families.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided source material.