Freescale Semiconductor
Advance Information
Document Number: MC34674
Rev. 2.0, 11/2008
High Input Voltage Travel
Charger for Single-cell Li-Ion
Batteries
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 28 V, 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 50 mA to 1.05 A with 8% accuracy and the constant-
output voltage in the CV-mode is fixed at 4.2 V with 0.4% accuracy over
-20°C to 70°C temperature range.
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 2.6 V 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 1.0
μA
current from the battery.
All the above functions are fit into a small 8-lead 2X3 UDFN package.
Features
• No external MOSFET, reverse-blocking diode or current-
sense resistor are required
• 28 V maximum input voltage rating with 11 V over-voltage
protection threshold
• Factory programmable charge current
• Trickle charge for fully discharged batteries
•
±0.4%
voltage accuracy over -20°C to 70°C
34674
POWER MANAGEMENT IC
EP SUFFIX (PB-FREE)
98ASA10774D
8-PIN UDFN
ORDERING INFORMATION
Device
Refer to
Table 1,
Device Variations
Temperature
Range (T
A
)
-40°C to 85°C
Package
8 UDFN-EP
• 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 mm
2
thermally enhanced UDFN package
• Pb-free packaging designated by suffix code EP
V
IN
VIN
C
IN
34674
BAT
R
PU
VREF
RED
GRN
OFF
ON
EN
GND
TEMP
R
S
TO BATTERY NTC
(THERMISTOR)
C
OUT
TO BATTERY
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.
PIN CONNECTIONS
PIN CONNECTIONS
VIN
GRN
RED
EN
1
2
EPAD
3
4
8
7
6
5
BAT
VREF
TEMP
GND
Figure 3. 34674 Pin Connections
Table 2. 34674 Pin Definitions
A functional description of each pin can be found in the Functional Pin Description section beginning on
page 12.
Pin Number
1
2
3
4
5
6
7
8
EPAD
Pin Name
VIN
GRN
RED
EN
GND
TEMP
VREF
BAT
EPAD
Pin Function
Input
Output
Output
Input
Ground
Input
Output
Output
N/A
Formal Name
Input supply
Green indicator
Red indicator
Enable
Ground
NTC interface input
NTC interface bias
voltage
Charger output
Exposed pad
The supply input.
Indication of the charge status. Open drain output with 6 mA current limit.
Indication of the charge status. Open drain output with 6 mA current limit.
Active-low enable logic input.
Ground.
The NTC thermistor interface pin.
The bias voltage for the NTC interface circuit.
The charger output pin to the battery.
Exposed pad for thermal dissipation enhancement. Must be soldered on
the large ground plane on the PCB to increase the thermal dissipation.
The pad must be connected to GND electrically.
Definition
34674
4
Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
MAXIMUM RATINGS
Table 3. Maximum Ratings
All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunction or
permanent damage to the device.
Ratings
ELECTRICAL RATINGS
Input voltage range
VIN Pin
GRN and RED Pins
EN, BAT, REF and TEMP Pins
ESD Voltage
(2)
Human Body Model (HBM)
Machine Model (MM)
THERMAL RATINGS
Operating Temperature
Ambient
Junction
Storage Temperature
Thermal Resistance
(3)
Junction-to-Case
Junction-to-Ambient
Peak Package Reflow Temperature During Reflow
(4),(5)
R
θJC
R
θJA
T
PPRT
10
70
Note 5
°C
T
A
T
J
T
STG
-40 to 85
-40 to 150
-65 to 150
°C
°C/W
°C
V
IN
V
GRN
, V
RED
V
EN
, V
BAT
,
V
REF
, V
TEMP
V
ESD
±2000
±200
-0.3 to 28
-0.3 to 12
-0.3 to 5.5
V
V
Symbol
Value
Unit
Notes
2. ESD testing is performed in accordance with the Human Body Model (HBM) (C
ZAP
= 100 pF, R
ZAP
= 1500
Ω),
and the Machine Model
(MM) (C
ZAP
= 200 pF, R
ZAP
= 0
Ω).
3.
4.
5.
Device mounted on the Freescale EVB test board per JEDEC DESD51-2.
Pin soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may
cause malfunction or permanent damage to the device.
Freescale’s Package Reflow capability meets Pb-free requirements for JEDEC standard J-STD-020C. For Peak Package Reflow
Temperature and Moisture Sensitivity Levels (MSL), Go to www.freescale.com, search by part number [e.g. remove prefixes/suffixes
and enter the core ID to view all orderable parts. (i.e. MC33xxxD enter 33xxx), and review parametrics.
34674
Analog Integrated Circuit Device Data
Freescale Semiconductor
5
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