Document Number: MC34675

Rev. 3.0, 4/2008

Freescale Semiconductor

Advance Information

* This document contains certain information on a new product.

Specifications and information herein are subject to change without notice.

© Freescale Semiconductor, Inc., 2008. All rights reserved.

28V-Input-Voltage Single-Cell

Li-Ion Battery Charger with

10mA Regulator

The 34675 is a high-input-voltage Li-Ion battery charger with a

4.85V/10mA linear regulator. The high input voltage, up to 28V,

eliminates the input over-voltage protection circuit required in handheld

devices such as cell phones, Bluetooth accessories, and portable

media players. The 4.85V linear regulator is capable of 10mA output

current and can be used to directly power a sub-system such as a USB

transceiver.

The charge cycle of the 34675 includes trickle, constant-current

(CC) and constant-voltage (CV) charge modes. The CC mode current

is programmable up to 1A, with an external resistor. The voltage across

the external resistor is also used to monitor the actual charge current.

The constant voltage is fixed at 4.2V with 0.7% accuracy over the

-40°C to 85°C temperature range. The trickle-mode current is pre-set

to 20% of the CC mode current when the battery voltage is lower than

the trickle-mode threshold. The end-of-charge (EOC) current threshold

is pre-set to 10% of the CC mode current, to save board space and

cost. A charge current thermal foldback feature limits the charge

current when the IC internal temperature rises to the preset threshold

of 120°C. The 34675 also protects the system with its input over-

voltage protection (OVP) feature. Two indication pins (PPR and CHG)

can be simply interfaced to a microprocessor or LEDs. When no power

supply is connected, or when disabled, the charger draws less than

1.0

μA leakage current from the battery.

Features

• No external MOSFET, reverse-blocking diode, or current-sense resistor is required

• Guaranteed maximum 1A programmable CC mode current

•

±0.7% voltage accuracy over -40°C to 85°C

•

±6% current accuracy over -40°C to 85°C

• 4.85V/10mA linear regulator with a 6.8V input over-voltage protection threshold

• 28V maximum voltage for the power input with a 6.8V over-voltage protection threshold

• Trickle charge for fully discharged batteries

• Charge current monitor

• Charge current thermal foldback

• Pb-free packaging designated by suffix code EP

Figure 1. 34675 Simplified Application Diagram

POWER MANAGEMENT IC

EP SUFFIX (PB-FREE)

98ASA10774D

8-PIN UDFN

34675

ORDERING INFORMATION

Device

Temperature

Package

MC34675AEP/R2

-40°C to 85°C

8-UDFN

ON

OFF

VIN

GND

CHG

PPR

EN

BAT

ISET

DET

TO BATTERY

TO SYSTEM

34675