LTC4009 TYPICAL APPLICATION Application Circuit

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LTC4009 circuit
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Pages : 28 Pages

Other Part Numbers in this pdf file

LTC4009CUF#TRPBF   LTC4009CUF#PBF  
Linear Technology Corporation

find LTC4009 datasheet
LTC4009 circuit
LTC4009
High Efficiency,
Multi-Chemistry
Battery Charger
FEATURES
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DESCRIPTION
The LTC4009 is a constant-current/constant-voltage Battery
charger controller. It uses a synchronous quasi-constant
frequency PWM control architecture that will not gener-
ate audible noise with ceramic bulk Capacitors Charge
current is set by the combination of external sense, input
and programming Resistors Current being delivered by
the charger can be monitored as a voltage across the
programming Resistor
The LTC4009 features fully adjustable output voltage. An
external Resistor divider and precision internal reference
set the final output voltage at which charge current will
be reduced to zero.
The device includes AC adapter input current limiting,
which maximizes charge rate for a fixed input power level.
An external sense Resistor programs the input current
limit, and the
ICL
status pin indicates when the Battery
charge current is being reduced as a result of AC adapter
current limiting.
The
CHRG
status pin is active during all charging modes,
including special indication when the charge current has
decreased below 10% of the programmed current.
General Purpose Battery Charger Controller
Efficient 550kHz Synchronous Buck PWM Topology
±0.5% Output Voltage Accuracy
Programmable Charge Current: 4% Accuracy
Programmable AC Adapter Current Limit:
3% Accuracy
No Audible Noise with Ceramic Capacitors
Wide Input Voltage Range: 6V to 28V
Wide Output Voltage Range: 5V to 28V
Indicator Outputs for AC Adapter Present, Charging,
C/10 Current Detection and Input Current Limiting
Analog Charge Current Monitor
Micropower Shutdown
Thermally Enhanced 20-Pin 4mm
×
4mm
×
0.75mm
QFN Package
APPLICATIONS
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Notebook Computers
Portable Instruments
Battery Backup Systems
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5723970.
TYPICAL APPLICATION
FROM
ADAPTER
13V TO 28V
20mΩ
0.1μF
DCIN
14.3k
CLP
0.1μF
5.1k
20μF
POWER TO
SYSTEM
Efficiency at DCIN = 20V
100
95
EFFICIENCY (%)
90
POWER LOSS
85
80
75
70
20μF
1.5k
CLN
DCDIV BOOST
LTC4009
TGATE
CHRG
SW
INTV
DD
BGATE
GND
10000
0.1μF
EFFICIENCY
POWER LOSS (mW)
TO/FROM
MCU
ACP
ICL
SHDN
ITH
6.04k
0.1μF
2μF
5μH
1000
V
FLOAT
= 12.3V
R
SENSE
= 33mΩ
R
IN
= 3.01k
R
PROG
= 26.7k
D
IN
L = IHLP-2525CZ 6.8μH
0
0.5
1.0
1.5
2.0
CHARGE CURRENT (A)
2.5
100
3.0
3.01k
CSP
33mΩ
3.01k
CSN
PROG
4.7nF
26.7k
V
FB
32.8k
BAT
FBDIV
301k
CHARGE
CURRENT
MONITOR
+
12.3V
Li-Ion
4009 TA01a
4009 TA01b
4009f
1