STMicroelectronics AN1941 Low Voltage LED Driver Application Note

This application note covers 3 DC-DC power supplies to drive high intensity LEDs, namely L6920D boost converter, L4971 buck converter and L6902D buck converter.

Brand: STMicroelectronics
Category: Other Electronics
Document type: Application Note
Language: English
Pages: 15
File format: PDF
File size: 499 KB
Published: 06 August, 2012
Updated: 30 September, 2023
Models: L4971, L6902D, L6920D
MD5 checksum: 420B69208E6F9393F4096C82697DDEB4
PDF: STMicroelectronics AN1941 Low Voltage LED Driver Application Note PDF

About this manual

This document presents three non-isolated DC-DC constant current LED driver reference designs developed by STMicroelectronics. The first design utilizes the L6920D boost converter to drive a single LED for flashlight applications from low voltage sources. The second design employs the L4971 buck converter to drive strings of 1 to 9 LEDs, while the third design uses the L6902D buck converter for driving 1 to 6 LEDs.

What's inside

Introduction
L6920D LED Driver
L6920D Circuit Description
L4971 Buck LED Driver
L4971 Circuit Description
LED Parameters
Conclusion

Specifications

L6920D Startup Voltage	1V
L6920D Operating Voltage	down to 0.6V
L6920D Quiescent Current	10uA
L6920D Internal MOSFET Resistance	120mQ
L4971 Output Current	1.5A
L4971 Input Voltage Range	20V to 55V
L4971 Minimum Input Voltage	8 volts

Frequently asked questions

What is the startup voltage for the L6920D?

The startup is guaranteed at 1V.

What is the maximum output current of the L4971?

The L4971 is able to deliver 1.5A.

What is the input voltage range for the L4971 buck driver?

The input ranges from 20 volts to 55 volts.

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