ULN2001D

Overview

The ULN2001D is a single-chip integrated high-voltage, high-current Darlington transistor array manufactured by UMW. It contains three independent Darlington transistor drive channels within an SOP-8 package. Each channel features a collector output current of 500mA and withstands a collector-emitter voltage of 50V. The device includes internal freewheeling diodes for inductive load protection and integrates 4K pull-down resistors to ground at each input stage. It operates with a working temperature range of -40°C to +85°C and accepts TTL/CMOS logic signals directly.

Feature Summary

• Integrates three independent Darlington transistor drive channels on a single chip
• Includes built-in freewheeling diodes for driving inductive loads such as relays and stepper motors
• Features internal 4K pull-down resistors at input stages to prevent unstable states
• Compatible with direct connection to TTL and CMOS logic circuits

Applications

• Relay drive circuits
• Stepper motor drive applications
• LED display screen drivers
• Logic buffer functions

Procurement Notes

Verify the specific manufacturer designation, as the ULN2001D part number is utilized by multiple semiconductor vendors including STMicroelectronics and Mixic. Confirm that the received component matches the UMW datasheet specifications, particularly the SOP-8 package dimensions and electrical parameters, to ensure compatibility with the intended circuit design.

Selection Notes

Select this component when a compact solution for driving multiple low-power inductive or resistive loads is required. The three-channel configuration makes it suitable for applications needing fewer pins than seven-channel arrays. Ensure the load current per channel does not exceed the 500mA rating and verify that the system voltage remains within the 50V collector-emitter limit.

Part Context

The ULN2001D belongs to the ULN200x series of Darlington arrays. While similar devices like the ULN2003 offer seven channels, the ULN200D provides a reduced three-channel option in a smaller footprint. This variation allows designers to optimize board space when only a limited number of driver outputs are necessary for the application.

Replacement Considerations

Direct substitutes include the ULN2003D (STMicroelectronics) which offers seven channels in a similar SOIC-16 package, though pinouts differ. For exact functional replacement in terms of channel count, verify availability from other manufacturers producing the three-channel variant.