LTC4000_15 Datasheet, PDF (1/40 Pages) Linear Technology – High Voltage High Current Controller for Battery Charging and Power Management

LTC4000
High Voltage High Current
Controller for Battery Charging
and Power Management
Features
Description
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}
Applications
n _{High Power Battery Charger Systems}
n _{High Performance Portable Instruments}
n _{Industrial Battery Equipped Devices}
n _{Notebook/Subnotebook Computers}
The LTC^®4000 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.
Typical Application
48V to 10.8V at 10A Buck Converter Charger for Three LiFePO₄ Cells
15V TO 60V
5mΩ
LT3845A
IN
SHDN
V_C
OUT
100µF
Si7135DP
14.7k
1.10M
ITH
RST
CLN
IN
1µF
VM
100k
3.0V
ENC
CHRG
FLT
IIMON
10nF
IBMON
10nF
TMR
47nF
CC
IID IGATE CSP
CSN
BGATE
BAT
OFB
LTC4000
FBG
BFB
NTC
CL
CX
GND BIAS
24.9k 22.1k
0.1µF
1µF
V_OUT
12V, 15A
1.15M 5mΩ
Si7135DP
127k
133k
1.13M
V_BAT
10.8V FLOAT
10A MAX CHARGE
CURRENT
10k
10k
3-CELL LiFePO₄
BATTERY PACK
NTHS0603
N02N1002J
4000 TA01a
For more information www.linear.com/LTC4000
Charge Current and V_OUT Profile
vs V_BAT During a Charge Cycle
12
11
10
I_CHARGE
V_OUT
10.5
8
V_OUT
10
6
9.5
4
9
2
I_CHARGE
0
6
7
8
9 10
V_BAT (V)
8.5
8
11 12
4000 TA01b
4000fb
1