LTC4000
1
4000fb
For more information
Charge Current and V
OUT
Profile
vs V
BAT
During a Charge Cycle
Typical applicaTion
FeaTures
DescripTion
High Voltage High Current
Controller for Battery Charging
and Power Management
is a high voltage, high performance controller
that converts many externally compensated DC/DC power
supplies into full-featured battery chargers.
Features of the LTC4000’s battery charger include: accurate
(±0.25%) programmable float voltage, selectable timer or
current termination, temperature qualified charging using
an NTC thermistor, automatic recharge, C/10 trickle charge
for deeply discharged cells, bad battery detection and
status indicator outputs. The battery charger also includes
precision current sensing that allows lower sense voltages
for high current applications.
The LTC4000 supports intelligent PowerPath control. An
external PFET provides low loss reverse current protec-
tion. Another external PFET provides low loss charging
or discharging of the battery. This second PFET also
facilitates an instant-on feature that provides immediate
downstream system power even when connected to a
heavily discharged or short faulted battery.
The LTC4000 is available in a low profile 28-lead 4mm
×
5mm QFN and SSOP packages.
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
48V to 10.8V at 10A Buck Converter Charger for Three LiFePO
4
Cells
applicaTions
n
Complete High Performance Battery Charger When
Paired with a DC/DC Converter
n
Wide Input and Output Voltage Range: 3V to 60V
n
Input Ideal Diode for Low Loss Reverse Blocking
and Load Sharing
n
Output Ideal Diode for Low Loss PowerPath™ and
Load Sharing with the Battery
n
Instant-On Operation with Heavily Discharged
Battery
n
Programmable Input and Charge Current:
±1% Accuracy
n
±0.25% Accurate Programmable Float Voltage
n
Programmable C/X or Timer Based Charge
Termination
n
NTC Input for Temperature Qualified Charging
n
28-Lead 4mm
×
5mm QFN or SSOP Packages
n
High Power Battery Charger Systems
n
High Performance Portable Instruments
n
Industrial Battery Equipped Devices
n
Notebook/Subnotebook Computers
1.13M
14.7k
127k
10k
10k
3-CELL LiFePO
4
BATTERY PACK
V
BAT
10.8V FLOAT
10A MAX CHARGE
CURRENT
NTHS0603
N02N1002J
1.15M
47nF
5mΩ
V
OUT
12V, 15A
15V TO 60V
Si7135DP
133k
CSN
CSP
BGATE
IGATE
BAT
OFB
FBG
BFB
NTC
CX
LTC4000
ITH
CC
IID
5mΩ
LT3845A
100µF
OUT
V
C
SHDN
IN
RST
CLN
IN
ENC
CHRG
FLT
VM
IIMON
IBMON
22.1k
TMR
GND BIAS
CL
24.9k
1µF
3.0V
1.10M
100k
10nF
10nF
1µF
0.1µF
4000 TA01a
Si7135DP
V
BAT
(V)
6
0
I
CHARGE
(A)
V
OUT
(V)
2
4
8
6
10
12
8
8.5
9
10
9.5
10.5
11
10
11
4000 TA01b
12
7
8
9
V
OUT
I
CHARGE
V
OUT
I
CHARGE
