Document Number: MC34674
Rev. 1.0, 01/2008
Freescale Semiconductor
Advance Information
High Input Voltage Travel
Charger for Single-cell Li-Ion
Batteries
34674
The MC34674 is a fully integrated single-cell Li-Ion and Li-Polymer
battery charger optimized for travel charger applications. The few
external components required include a dual-color LED for charge-
status indication, a negative temperature coefficient (NTC) thermistor
circuit for setting the charge temperature window, and two decoupling
capacitors. The high input voltage, up to 28V, allows low-cost ac/dc
converters to be used for further system cost reduction. A typical
charge cycle of the MC34674 includes trickle, constant-current (CC)
and constant-voltage (CV) charge modes. The CC-mode current is
selectable from 50mA to 1.05A with 8% accuracy and the constant-
output voltage in the CV-mode is fixed at 4.2V with 0.4% accuracy over
-20°C to 70°C temperature range.
POWER MANAGEMENT IC
EP SUFFIX (PB-FREE)
98ASA10774D
8-PIN UDFN
The MC34674 has all the features such as trickle charging for a
deeply discharged battery, an internal timer for termination to prevent
charging a failed battery, charger current thermal foldback for thermal
protection, and smart battery connection verification to prevent
charging in case there is no battery connected. It also protects the
system with its input over-voltage protection (OVP) feature. In addition,
it has a 2.6V falling power-on-reset (POR) threshold, making it perfect
to work with current limited power supplies. When the charger is
disabled, the BAT pin leaks less than 1µA current from the battery. All
the above functions are fit into a small 8-lead 2X3 UDFN package.
ORDERING INFORMATION
Temperature
Package
Device
MC34674AEP/R2
Range (T )
A
-40°C to 85°C
8-UDFN
Features
• No external MOSFET, reverse-blocking diode or current-
sense resistor are required
• 28V maximum input voltage rating with 11V over-voltage
protection threshold
• Factory programmable charge current
• Trickle charge for fully discharged batteries
• Driving a dual-color LED and smart battery connection
verification optimized for travel charger applications
• Interface to NTC thermistor
• Internal timer and thermal current limit
• Small 2X3 mm2 thermally enhanced UDFN package
• Pb-free packaging designated by suffix code EP
•
±0.4% voltage accuracy over -20°C to 70°C
34674
VIN
VIN
BAT
TO BATTERY
COUT
CIN
RPU
VREF
TEMP
RED
GRN
EN
RS
TO BATTERY NTC
(THERMISTOR)
OFF
ON
GND
Figure 1. 34674 Simplified Application Diagram
* This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2007-8. All rights reserved.