LTC4015_15 Datasheet, PDF (29/76 Pages) Linear Technology – Multichemistry Buck Battery Charger Controller with Digital Telemetry System

Operation
LTC4015
CHARGER_
SUSPENDED*
BATTERY
DETECTION
NO BATTERY
BATTERY
VOLTAGE
STABLE
SHORTED
BATTERY
MAX_CHARGE_TIMER STARTS
BAT_MISSING_
FAULT
BAT_SHORT_
FAULT
30 SECOND
TIME OUT
V_BAT < 35%
OF V_CHARGE
MAX_CHARGE_TIME_FAULT
MAX_CHARGE_TIME
PASSED
ABSORB_TIME PASSED
—OR—
(ABSORB VOLTAGE REACHED AND
ICHG < C_OVER_X_THRESHOLD)
CC_CV_CHARGE
VABSORB_DELTA > 0
ABSORB_TIMER STARTS
ABSORB
CHARGE
NTC_RATIO
BELOW JEITA_T7
OR ABOVE JEITA_T1
NTC_RATIO
BELOW JEITA_T7
OR ABOVE JEITA_T1
BATTERY AT V_CHARGE (CV)
—AND—
I_CHG < C_OVER_X_THRESHOLD
—AND—
EN_C_OVER_X_TERM = 1
RECHARGE THRESHOLD
REACHED
RECHARGE THRESHOLD
REACHED
C_OVER_X_TERM
TO NTC
PAUSE
MAX_CV_TIME PASSED
WITH BATTERY AT
V_CHARGE (CV)
—AND—
NOT (MAX_CV_TIME = 0)
TIMER_TERM
TO NTC
PAUSE
* NOTE: ALL STATES RETURN TO CHARGER SUSPENDED IF ANY OF THE FOLLOWING OCCUR:
A. THE INPUT VOLTAGE VIN FALLS TO WITHIN 100mV OF THE BATSENS PIN VOLTAGE.
B. SUSPEND_CHARGER IS WRITTEN TO 1 VIA THE SERIAL PORT.
C. A SYSTEM FAULT OCCURS (V_IN OVERVOLTAGE LOCKOUT, 2P5V_CC UNDERVOLTAGE LOCKOUT, INTV_CC
UNDERVOLTAGE LOCKOUT, DRV_CC UNDERVOLTAGE LOCKOUT. THERMAL SHUTDOWN, MISSING RT
RESISTOR, OR INVALID COMBINATION OF CELLS PINS).
RETURN TO PREVIOUS
CHARGE STATE
NTC_RATIO
BETWEEN JEITA_T7
AND JEITA_T1
NTC_PAUSE
NTC_RATIO
OUT OF RANGE
TO BAT_MISSING_
FAULT
4015 F05a
Figure 5B. LiFePO₄ Battery Charging State Diagram
For more information www.linear.com/LTC4015
4015f
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