© Freescale Semiconductor, Inc., 2008. All rights reserved.
Freescale Semiconductor
User’s Guide
Document Number: KT34674UG
Rev. 1.0, 3/2008
1 Purpose
This User Guide helps the Li-Ion battery travel
charger designer to understand the MC34674 and
its evaluation board. It illustrates the design
procedure when using MC34674 to design a Li-Ion
battery charger and the way to get the best
performance of the MC34674.
2 Scope
The MC34674 is a high input voltage single-cell
Li-Ion battery charger optimized for travel charger
application. Only a dual-color LED indicator, a
thermistor, and two de-couple capacitors are
required to design the travel charger. It also
features ±0.4% output voltage accuracy and ±8%
charge current accuracy over-temperature range.
Its high input voltage of 28V allows low cost AC/DC
adapter to be used to save the total cost. The
charge current is preset by the factory from 50mA
through 1050mA. The end of charge (EOC) current
is preset to 10% of the CC-mode charge current by
the factory. When the battery voltage is below the
Using the High-Input-Voltage Travel Charger
for Single Cell Li-Ion Batteries
(KIT34674EPEVBE)
Contents
1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 Application Diagram . . . . . . . . . . . . . . . . . . . . 2
4 Evaluation Board Specification . . . . . . . . . . . 2
5 Component Selection . . . . . . . . . . . . . . . . . . . 4
6 Layout Design . . . . . . . . . . . . . . . . . . . . . . . . . 5
7 Evaluation Board Configuration . . . . . . . . . . 7
8 Test Setup with the Evaluation Board. . . . . . 8
9 References. . . . . . . . . . . . . . . . . . . . . . . . . . . 10
