MIC79050
Micrel
MIC79050
Simple Lithium-Ion Battery Charger
Preliminary Information
General Description
The MIC79050 is a simple single-cell lithium-ion battery
charger. It includes an on-chip pass transistor for high preci-
sion charging. Featuring ultrahigh precision (+0.75% over the
Li-ion battery charging temperature range) and “zero” off
mode current, the MIC79050 provides a very simple, cost
effective solution for charging lithium-ion battery.
Other features of the MIC79050 include current limit and
thermal shutdown protection. In the event the input voltage to
the charger is disconnected, the MIC79050 also provides
minimal reverse-current and reversed-battery protection.
The MIC79050 is a fixed 4.2V device and comes in the
thermally-enhanced MSO-8, SO-8, and SOT-223 packages.
The 8-pin versions also come equipped with enable and
feedback inputs. All versions are specified over the tempera-
ture range of –40°C to +125°C.
Features
• High accuracy charge voltage:
±0.75%
over -5°C to + 60°C (Li-ion charging
temperature range)
• “Zero” off-mode current
• 10µA reverse leakage
• Ultralow 380mV dropout at 500mA
• Wide input voltage range
• Logic controlled enable input (8-pin devices only)
• Thermal shutdown and current limit protection
• Power MSOP-8, Power SOP-8, and SOT-223
• Pulse charging capability
Applications
•
•
•
•
•
Li-ion battery charger
Celluar phones
Palmtop computers
PDAs
Self charging battery packs
Ordering Information
Part Number
MIC79050-4.2BS
MIC79050-4.2BM
MIC79050-4.2BMM
Voltage
4.2V
4.2V
4.2V
Junct. Temp. Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
SOT-223
SOP-8
MSOP-8
Typical Applications
Regulated or
unregulated
wall adapter
MIC79050-4.2BS
IN
BAT
GND
4.2V
±0.75%
Over Temp
Li-Ion
Cell
Simplest Battery Charging Solution
Regulated or
unregulated
wall adapter
MIC79050-4.2BMM
IN
BAT
EN
FB
GND
4.2V
±0.75%
Li-Ion
Cell
External PWM*
*See Applications Information
Pulse-Charging Application
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
June 2000
1
MIC79050
MICREL [ MICREL SEMICONDUCTOR ]
