LTC4060
Standalone Linear NiMH/NiCd
Fast Battery Charger
FEATURES
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DESCRIPTIO
Complete Fast Charger Controller for Single,
2-, 3- or 4-Series Cell NiMH/NiCd Batteries
No Firmware or Microcontroller Required
Termination by –∆V, Maximum Voltage or
Maximum Time
No Sense Resistor or Blocking Diode Required
Automatic Recharge Keeps Batteries Charged
Programmable Fast Charge Current: 0.4A to 2A
Accurate Charge Current:
±5%
at 2A
Fast Charge Current Programmable Beyond 2A with
External Sense Resistor
Automatic Detection of Battery
Precharge for Heavily Discharged Batteries
Optional Temperature Qualified Charging
Charge and AC Present Status Outputs Can Drive LED
Automatic Sleep Mode with Input Supply Removal
Negligible Battery Drain in Sleep Mode: <1µA
Manual Shutdown
Input Supply Range: 4.5V to 10V
Available in 16-Lead DFN and TSSOP Packages
The LTC
®
4060 is a complete fast charging system for NiMH
or NiCd batteries. Just a few external components are
needed to design a standalone linear charging system.
An external PNP transistor provides charge current that is
user programmable with a resistor. A small external capaci-
tor sets the maximum charge time. No external current
sense resistor is needed, and no blocking diode is required.
The IC automatically senses the DC input supply and bat-
tery insertion or removal. Heavily discharged batteries are
initially charged at a C/5 rate before a fast charge is applied.
Fast charge is terminated using the –∆V detection method.
Backup termination consists of a programmable timer and
battery overvoltage detector. An optional external NTC ther-
mistor can be used for temperature-based qualification of
charging. An optional programmable recharge feature au-
tomatically recharges batteries after discharge.
Manual shutdown is accomplished with the SHDN pin, while
removing input power automatically puts the LTC4060 into
sleep mode. During shutdown or sleep mode, battery drain
is <1µA.
The LTC4060 is available in both low profile (0.75mm) 16-
pin 5mm
×
3mm DFN and 16-lead TSSOP packages. Both
feature exposed metal die mount pads for optimum ther-
mal performance.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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Portable Computers, Cellular Phones and PDAs
Medical Equipment
Charging Docks and Cradles
Portable Consumer Electronics
TYPICAL APPLICATIO
2-Cell, 2A Standalone NiMH Fast Charger with
Optional Thermistor and Charge Indicator
V
IN
= 5V
BATTERY VOLTAGE (V)
2-Cell NiMH Charging Profile
3.40
–∆V
TERMINATION
3.30
330Ω
“CHARGE”
SHDN
CHRG
V
CC
ACP
SENSE
NTC
698Ω
DRIVE
NTC
LTC4060
BAT
PROG
ARCT
SEL0
SEL1
TIMER
CHEM
PAUSE
GND
1.5nF
4060 TA01
+
3.20
NiMH
BATTERY
3.10
0
10
50
20
30
40
CHARGE TIME (MINUTES)
60
U
4060 TA01b
U
U
4060f
1
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
