LTC3305_15 Datasheet, PDF (1/28 Pages) Linear Technology – Lead-Acid Battery Balancer

LTC3305
Lead-Acid Battery Balancer
Features
n _{Single IC Balances Up to Four 12V Lead-Acid}
Batteries in Series
n _{All NFET Design}
n _{Stackable to Balance Larger Series Battery Packs}
n _{Standalone Operation Requires no External µP or}
Control Circuitry
n _{Balancing Current Limited by External PTC Thermistor}
n _{Continuous Mode and Timer Mode}
n _{Programmable UV and OV Fault Thresholds}
n _{Programmable Termination Time and Termination}
Voltage
n _{Thermally Enhanced 38-Lead TSSOP Package}
Applications
n _{Telecom Backup Systems}
n _{Home Battery Powered Backup Systems}
n _{Industrial Electric Vehicles}
n _{Energy Storage Systems (ESS)}
n _{Medical Equipment}
Description
The LTC^®3305 balances up to 4 lead-acid batteries
connected in series. All voltage monitoring, gate drive,
and fault detection circuitry is integrated. The LTC3305
is designed for standalone operation and does not require
any external control circuitry.
The LTC3305 employs an auxiliary battery or an alternative
storage cell to transfer charge to or from each individual
battery in the stack. A mode pin provides two operating
modes, timer mode and continuous mode. In timer mode,
once the balancing operation is completed, the LTC3305
goes into a low power state for a programmed time and then
periodically rebalances the batteries. In continuous mode,
the balancing operation continues even after the batteries
are balanced to their programmed termination voltage.
The LTC3305 is available in a thermally enhanced 38-lead
TSSOP package.
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.
Typical Application
4-Battery Balancer with Programmed High and Low Battery Voltage Faults
10µF
25V
1µF
6V
100k EACH
10nF
V_REG ^CM
EN1
EN2
MODE
TERM1
TERM2
CP
BOOST
V4
UVFLT
OVFLT
DONE
V3
BAL
PTCFLT
BATX
BATY
CTON
LTC3305
V2
CTOFF
100nF
V1
CTBAT
10nF
V_L
27.4k
V_H
42.2k
I_SET
12.1k
9
NGATE1-9
AUXP
AUXN
GND
249Ω
10µF
25V
10µF
25V
1.33k
10µF
25V
10µF
25V
10µF
NGATE6
25V
NGATE7
PTC
10µF
+
AUX
25V
6.04k
6.04k
6.04k
6.04k
NGATE8
NGATE9
6.04k
NGATE5
6.04k
NGATE4
+
BAT4
3.01k
NGATE3 ₊
BAT3
NGATE2
+
6.04k
BAT2
NGATE1
6.04k
BAT1
+
3305 TA01
For more information www.linear.com/LTC3305
Battery Voltages Converge
Over Time
16
14
12
10
8
6
4
BATTERY 1
BATTERY 2
2
BATTERY 3
BATTERY 4
0
TIME
3305 TA01a
3305f
1