LTC3305_15 Datasheet, PDF (10/28 Pages) Linear Technology – Lead-Acid Battery Balancer

LTC3305
Pin Functions
I_SET (Pin 29): Reference Current Pin that Servos to 1.2V.
A resistor from this pin to GND programs the gate charge
current for the external NMOS switches. The reference
current is also used to program the undervoltage and
overvoltage thresholds.
V_REG (Pin 30): Low Voltage Regulated Output. An inter-
nally generated voltage of 2.5V is always present at this
pin. The voltage at this pin may be overdriven by a higher
external voltage up to 5.5V. This pin has limited current
sink capability and will not pull down a higher externally
applied voltage. All logic input pins must be referenced to
this pin. Decouple with a 1µF capacitor to GND.
TERM2 (Pin 31): Termination Threshold Select. This pin
along with TERM1 is used to set the voltage difference
between the battery and auxiliary cell at which a battery is
deemed balanced. High input impedance pin, do not float.
TERM1 (Pin 32): Termination Threshold Select. This pin
along with TERM2 is used to set the voltage difference
between the battery and auxiliary cell at which a battery is
deemed balanced. High input impedance pin, do not float.
EN2 (Pin 33): Enable Input. The state of the EN1 and EN2
pins is used to indicate the number of batteries in the stack.
With both pins at GND, the part is in shutdown. High input
impedance pin, do not float.
EN1 (Pin 34): Enable Input. The state of the EN1 and EN2
pins is used to indicate the number of batteries in the stack.
With both pins at GND, the part is in shutdown. High input
impedance pin, do not float.
MODE (Pin 35): Mode Select. When held high, continuous
mode is selected. When held low, timer mode is selected.
High input impedance pin, do not float.
No Connect (Pin 36): This pin is not connected internally.
Solder this pin to a pad electrically isolated from all other
circuit nodes.
CP (Pin 37): Positive Terminal of Charge Pump Flying
Capacitor. Connect a 10µF capacitor from this pin to CM
for charge pump operation.
CM (Pin 38): Negative Terminal of Charge Pump Flying
Capacitor. Connect a 10µF capacitor from this pin to CP
for charge pump operation.
GND (Pin 39): The exposed pad is ground and must be
soldered to PCB ground for electrical connectivity and
rated thermal performance.
3305f
10
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