NCR321UX

Overview

The NCR321UX is a linear LED driver IC manufactured by Nexperia USA Inc., designed for constant current regulation in surface-mount applications. It integrates an NPN transistor with two diodes on a single chip within an SOT457 (SC-74; TSOP6) plastic package. The device supports a stabilized output current of 10 mA without external components, adjustable up to 250 mA via an external resistor. It features a low voltage overhead of 1.4 V and supports digital PWM input up to 10 kHz for dimming control. Qualified under AEC-Q101 standards, it operates with a supply voltage up to 16 V and handles power dissipation up to 750 mW.

Feature Summary

• Stabilized output current capability of 10 mA without external resistors
• Adjustable output current up to 250 mA using an external resistor
• Digital PWM input support for dimming control up to 10 kHz frequency
• Low voltage overhead of 1.4 V reduces component count and board space

Applications

• Automotive interior lighting systems
• Dashboard instrumentation displays
• Number plate illumination circuits

Procurement Notes

Verify the specific suffix 'U' corresponds to the SOT457 package configuration when sourcing. Confirm AEC-Q101 qualification requirements match target automotive reliability standards. Ensure design accounts for the 750 mW power dissipation limit and 16 V maximum supply voltage constraints during procurement planning.

Selection Notes

Select this component for designs requiring a compact, single-chip solution for constant current LED driving. The integrated resistor-free 10 mA mode simplifies circuitry for fixed-brightness applications. For variable brightness needs, utilize the PWM input feature. Consider the SOT457 package dimensions for PCB layout optimization in space-constrained automotive modules.

Part Context

This part belongs to the NCR321 series of LED drivers from Nexperia, which are ballast transistors designed for automotive lighting. The series includes variants like NCR320U, sharing similar functional characteristics but potentially differing in specific electrical parameters or packaging details. These devices address the need for reliable, space-saving current regulation in vehicle lighting architectures.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Verify compatibility with existing circuit designs before considering alternative manufacturers or generic equivalents.

FAQ

What is the maximum PWM frequency supported by the NCR321UX?

The NCR321UX supports a digital PWM input frequency of up to 10 kHz.

How is the output current adjusted on the NCR321UX?

The output current can be stabilized at 10 mA without external components or adjusted up to 250 mA by connecting an external resistor.