20V Battery Gas Gauge

20V Battery Gas Gauge
The LTC®2943 multicell battery gas gauge makes direct measurements of 3.6V to 20V battery stacks. Absolutely no level shifting
circuitry is required to interface with multicell voltages, minimizing current consumption and preserving measurement accuracy.
The LTC2943 is a true high voltage gas gauge that measures charge, voltage, current and temperature to within 1% accuracy —
all of the essential parameters required to accurately assess battery state of charge (SOC).
Features
Measures Accumulated Battery Charge and Discharge
3.6V to 20V Operating Range for Multicell Applications
14-Bit ADC Measures Voltage, Current and Temperature
1% Charge, Voltage, Current and Temperature Accuracy
I2C/SMBus Interface
Configurable Alert Output/Charge Complete Input
Quiescent Current <120µA
Small 8-Pin 3mm × 3mm DFN Package
n
2.0
n
Total Charge Error vs
Differential Sense Voltage
VSENSE+ = 10V
1.5
n
CHARGE ERROR (%)
n
n
n
n
n
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
1
0.1
I2C Battery Gas Gauges
Interface
2.7 to 5.5
I2C
LTC2941-1
2.7 to 5.5
I2C
LTC2942
2.7 to 5.5
I2C
LTC2942-1
2.7 to 5.5
I2C
LTC2943
3.6 to 20
I2C
LTC4150
2.7 to 8.5
Interrupt
•
LTC2941
100
Integrated
Sense Resistor
Measures
Operating
Range (V)
Part Number
10
VSENSE (mV)
Charge
Voltage
Current
Temperature
•
•
•
Package (mm)
2 × 3 DFN-6
•
2 × 3 DFN-6
•
•
•
•
•
•
L, LT, LTC, LTM, Linear Technology and the Linear logo are
registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
•
•
2 × 3 DFN-6
•
2 × 3 DFN-6
•
3 × 3 DFN-8
MSOP-10
Power Management Multicell Battery Chargers
24V AD/DC
ADAPTER
MBRS140
10µF
VIN
L
LT3652
SW
1µF
22µH
BOOST
SHDN
SENSE
CHRG
BAT
FAULT
VFB
TIMER
NTC
0.05Ω
953k
4.7µF
3.3V
340k
10k
B = 3380
SYSTEM LOAD
2k
2k
10µF
L
LTC2943
2k
VDD
ALCC
µP
SDA
SCL
SENSE+
RSENSE
SENSE –
GND
+
3-CELL
Li-Ion
BATTERY
The LT®3652 is a complete monolithic step-down battery charger that operates over a 4.95V to 32V input voltage range. The LT3652
provides a constant-current/constant-voltage charge characteristic, with maximum charge current externally programmable up to 2A.
The charger employs a 3.3V float voltage feedback reference, so any desired battery float voltage up to 14.4V can be programmed with
a resistor divider. The LT3652HV increases this range to 18V.
The LT3652 employs an input voltage regulation loop, which reduces charge current if the input voltage falls below a programmed level,
set with a resistor divider. When the LT3652 is powered by a solar panel, the input voltage regulation loop is used to maintain the panel
at peak output power.
Battery Chargers for Multicell Applications
Part Number
Maximum
Charge
Current (A)
VBAT
Range
(V)
Number of
Battery
Battery
Chemistry Cells (Series)
Switch Mode Multichemistry Buck (Step-Down) Battery Chargers
LT3652
2
3.3 to
SLA
SLA
14.4
LiFePO4
1-4 LiFePO4
Li-Ion
1-3 Li-Ion
LT3652HV
2
3.3 to 18
SLA
SLA
LiFePO4
1-5 LiFePO4
Li-Ion
1-4 Li-Ion
LTC4009/LTC4009-1‡ /
4
2 to 28
NiMH NiCd
2-18 Ni,
LTC4009-2‡
SLA Li-Ion
1-6 Li-Ion
LTC4012/LTC4012-1‡ /
4
2 to 28
NiMH NiCd
2-18 Ni,
LTC4012-2‡ /LTC4012-3
SLA Li-Ion
1-6 Li-Ion
LTC4000 # /LTC4000-1#$
50§
3 to 60
SLA
SLA
LiFePO4
1-16 LiFePO4
Li-Ion
1-14 Li-Ion
Input
Voltage
(V)
Integrated
Power
Charge
Package
Transistor Synchronous Termination (mm × mm)
4.9 to 32†
~
–
Timer or C/10
3×3 DFN-12,
MSOP-12E
4.9 to 34†
~
–
Timer or C/10
3×3 DFN-12,
MSOP-12E
6 to 28
–
~
External µC
4×4 QFN-20
6 to 28
–
~
External µC
4×4 QFN-20
3 to 60@
–
–
Timer + C/X
4×5 QFN-28
SSOP-28
4 to 5.5
~
~
–
Timer
3×3 QFN-16
~
Timer + C/10
~
–
Timer + C/10
~
~
Timer + C/10
3×3 DFN-12
MSOP-12E
3×3 DFN-12
MSOP-12E
5×6 QFN-36
~
~
Timer + C/10
5×6 QFN-36
Switch Mode Li-Ion Buck (Step-Down) Battery Chargers
LTC4001/LTC4001-1*
2
4.2
Li-Ion
1
LT3650-4.1/LT3650-4.2
2
4.1, 4.2
Li-Ion
1
LT3650-8.2/LT3650-8.4
2
8.2, 8.4
Li-Ion
2
LT3651-4.1/LT3651-4.2
4
4.1, 4.2
Li-Ion
1
4.75 to 32†
(40 Max)
9 to 32†
(40 Max)
6.5 to 32
LT3651-8.2/LT3651-8.4
4
8.2, 8.4
Li-Ion
2
9 to 32
†
Minimum start-up voltage is +3.3V above VBATMAX ‡ -1 and -2 versions are fixed voltage options for 1-4 Li-Ion cells $ -1 option has MPPC (Maximum Power Point Control) * 4.1V cell voltage
# Charging controller requires externally compensated switching regulator
§ Depends on external components
@ Greater than 60V is possible without the input current regulation/measurement function
www.linear.com/LTC2943 n 1-800-4-LINEAR
1013
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