Datasheet

Batteryvoltage,
V(BAT)
Charge
Complete
Status,
Charger
Off
Pre-
conditioning
Phase
Current
Regulation
Phase
VoltageRegulationand
ChargeTermination
Phase
PRE-CHARGE
CURRENT AND
TERMINATION
THRESHOLD
BatteryCurrent,
I(BAT)
V
O(BATREG)
V
(LOWV)
T
(PRECHG)
T
(CHG)
FAST-CHARGE
CURRENT
I
O(BAT)
I
O(PRECHG) ,
I
(TERM)
DONE
DONE
BAT
ISET 1
I /K
(OUT) (SET)
OUT
ChargeVoltage
Loop
Battery
Switch
SystemVoltage
RegulationLoop
VREF
Thermal
Loop
VTJ
V
(OUT)
I
(BAT)
V
(BAT)
V
O(REG)
V
O(REG)
TPS65820
SLVS663B – MAY 2006 – REVISED APRIL 2008 .............................................................................................................................................................. www.ti.com
Figure 34. Typical Charge Cycle, Thermal Loop not Active
If the operating conditions cause the IC junction temperature to exceed 125 ° C the charge cycle is modified, with
the activation of the integrated thermal control loop. The thermal control loop is activated when an internal
voltage reference, which is inversely proportional to the IC junction temperature, is lower than a fixed,
temperature-stable internal voltage. The thermal loop overrides the other charger control loops and reduces the
charge current until the IC junction temperature returns to 125 ° C, effectively regulating the IC junction
temperature.
Figure 35. Voltage and Thermal Regulation Loops
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