MC34675 Datasheet, PDF (1/24 Pages) Freescale Semiconductor, Inc – 28V-Input-Voltage Single-Cell Li-Ion Battery Charger with 10mA Regulator

Freescale Semiconductor
Advance Information
Document Number: MC34675
Rev. 3.0, 4/2008
28V-Input-Voltage Single-Cell
Li-Ion Battery Charger with
10mA Regulator
34675
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
1.0μA leakage current from the battery.
POWER MANAGEMENT IC
EP SUFFIX (PB-FREE)
98ASA10774D
8-PIN UDFN
ORDERING INFORMATION
Device
MC34675AEP/R2
Temperature
Range (T_A)
-40°C to 85°C
Package
8-UDFN
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
34675
V_IN
VIN
BAT
TO BATTERY
C_IN
GND
C_OUT
ISET
CHG
R_ISET
OFF
ON
PPR
EN
DET
C_DET
TO SYSTEM
Figure 1. 34675 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., 2008. All rights reserved.