ULN2065B

Overview

The ULN2065B is a quad NPN Darlington transistor array manufactured by STMicroelectronics. It features four independent switching channels with integral suppression diodes for inductive load protection and common emitters. The device supports an output current of up to 1.75 A per channel, with a collector-emitter breakdown voltage (Vceo) of 80 V and a sustaining voltage of at least 35 V measured at 100 mA. Inputs are compatible with popular 5 V logic families. The component operates within a temperature range of -20°C to +85°C, dissipates 1 W of power, and utilizes a SOT-23 surface-mount package measuring 2.90 x 1.65 mm with a height of 1.10 mm.

Feature Summary

• Contains four NPN Darlington switches with integral suppression diodes for inductive loads
• Compatible with popular 5 V logic families for direct interface
• Features common emitter configuration with high current delivery capability

Applications

• Interface logic circuits to high current, high voltage loads
• Driving inductive loads such as relays or solenoids
• General purpose switching applications requiring isolation from control logic

Procurement Notes

Verify the specific package variant upon ordering, as datasheets may reference DIP configurations while market listings indicate SMT availability. Confirm the manufacturer source directly through authorized distributors to ensure authenticity. Check for any obsolete status updates or lifecycle changes before finalizing procurement plans.

Selection Notes

Select this component when interfacing 5 V logic with loads requiring up to 1.75 A. Ensure the application voltage does not exceed the 80 V breakdown rating. Consider the thermal dissipation requirements given the 1 W power rating and compact SOT-23 footprint. Verify compatibility with the specific logic family driving the inputs.

Part Context

The ULN2065B belongs to the ULN20xx series of Darlington arrays designed for robust logic-to-load interfacing. It shares architectural similarities with variants like the ULN2067B and ULN2069B but differs in input voltage compatibility and internal pre-driver stages. This specific model targets 5 V logic systems, distinguishing it from CMOS/PMOS compatible versions in the same family.

Replacement Considerations

The ULN2067B offers similar functionality but is compatible with 6-15 V CMOS and PMOS logic rather than 5 V TTL. The ULN2069B includes a pre-driver stage to reduce loading on control logic. Designers must verify input voltage levels and pinout compatibility when substituting these related models.