UCC2956 Datasheet, PDF (1/10 Pages) Texas Instruments – Switch Mode Lithium-Ion Battery Charger Controller

UCC2956
UCC3956
Switch Mode Lithium-Ion Battery Charger Controller ^PRELIMINARY
FEATURES
• Precision 4.1V Reference (1%)
• High Efficiency Battery Charger Solution
• Average Current Mode Control from
Trickle to Over Charge
• Resistor Programmable Charge Currents
• Internal State Logic Provides Four
Charge States
• Programmable Over Charge Time
• Fully Differential Switch Mode Current
Sensing
• CHG Pin Initiates Charging
DESCRIPTION
The UCC3956 family of Switch Mode Lithium-Ion Battery Charger
Controllers accurately control lithium-ion battery charging with a
highly efficient average current control loop. This chip is designed to
work as a stand alone charger controller for a single cell or multiple
cell battery pack. This chip combines charge state logic and aver-
age current PWM control circuitry with a 14 bit counter to program
the over charge time. The charge state logic indicates current or
voltage control depending on the charge state. The chip includes
undervoltage lockout circuitry to insure sufficient supply voltage is
present before output switching starts. Additional circuit blocks in-
clude a differential current sense amplifier, a 1% voltage reference,
voltage and current error amplifiers, PWM latch, charge state de-
code bits, and a 500mA output driver.
BLOCK DIAGRAM
1/98
UDG-96197-1