ZXSC310-DN63: 12.5mA @ 40V Max, 3.7V in

Summary

Low cost, small simple and low power multi-LED drive solutions are important in applications including LCD backlight, key illuminations and effects for handheld devices (e.g. cell phones), signage and indicators. The LED current is generally between 10mA to 30mA and is powered from a single cell Li-Ion or three cell alkaline/NiMH/NiCad batteries. For battery powered applications low shutdown quiescent current is important to conserve battery life.

Figure 1 shows a simple low cost boost convertor, ZXSC310, driving eight series connected LEDs. ZXSC310 is in a small SOT23-5 package. The design solution is for an application with an input voltage range of 4.5V to 2.5V (e.g. a single cell Li-Ion can have a voltage range of 4.3V to 2.6V) with LED current optimized at 20mA typical, at 4.0V supply. The LED current at 4V is chosen to match the 20mA typical forward current of the LED used.

Specifications

Manufacturer Diodes Incorporated
Category Lighting
Sub-Category LED Drivers - DC In
Eval Board Board not Stocked
Voltage In 2.5 ~ 4.5 V
Topology Step Up
Current Out 12.5 mA @ 3.7V
Voltage Out (Max) 40 V
Outputs and Type 1 Non-Isolated
Efficiency @ Conditions >79%, 3.5 ~ 4V in, 32V @ 25mA
Features Shutdown, Enable, Standby
Switching Frequency 200 kHz
Component Count + Extras 6 + 0
Design Author Diodes/Zetex
Application / Target Market Cell Phones
Main I.C. Base Part ZXSC310
Date Created By Author
Date Added To Library 2011-03

Support Documents & Media

ZXSC310 - DN63 - Design Note 63 ZXSC310 - Datasheet

Media

ZXSC380_DN63_Schematic ZXSC310_DN63_Chart_1.JPG ZXSC310_DN63_Chart_2.JPG