ltm8062 Linear Technology Corporation, ltm8062 Datasheet - Page 9

• Manufacturer Part Number: ltm8062
• Description: Ltm8062 32vin, 2a ?module Power Tracking Battery Charger Features
• Manufacturer: Linear Technology Corporation

OPERATION
which termination scheme is used. When the timer-based
scheme is used, the LTM8062 also supports bad battery
detection, which triggers a system fault if a battery stays
in precondition mode for more than one-eighth of the total
programmed charge cycle time.
Once charging terminates and the LTM8062 is not actively
charging, the charger automatically enters a low current
standby mode in which supply bias currents are reduced
to 85μA. If the battery voltage drops 2.5% from the full
charge float voltage, the LTM8062 engages an automatic
charge cycle restart. The IC also automatically restarts a
new charge cycle after a bad-battery fault once the failed
BATTERY VOLTAGE
BATTERY VOLTAGE
BATTERY CHARGE
BATTERY CHARGE
Figure 1. Typical C/10 Terminated Charge Cycle (TMR Grounded, Time Not to Scale)
CURRENT
CURRENT
FAULT
FAULT
CHRG
CHRG
RUN
RUN
Figure 2. Typical EOC (Timer-Based) Terminated Charge Cycle
(Capacitor Connected to TMR, Time Not to Scale)
< t
EOC
/8
t
EOC
battery is removed and replaced with another battery.
The LTM8062 contains a battery temperature monitoring
circuit. This feature, using a thermistor, monitors battery
temperature and will not allow charging to begin, or will
suspend charging, and signal a fault condition if the bat-
tery temperature is outside a safe charging range. The
LTM8062 contains two digital open-collector outputs,
CHRG and FAULT, which provide charger status and signal
fault conditions. These binary coded pins signal battery
charging, standby or shutdown modes, battery temperature
faults and bad battery faults. For reference, C/10 and TMR
based charging cycles are shown in Figures 1 and 2.
AUTOMATIC
RESTART
1
0
1
0
1
0
FLOAT VOLTAGE
RECHARGE THRESHOLD
PRECONDITION THRESHOLD
MAXIMUM CHARGE CURRENT
PRECONDITION CURRENT
C/10
0 AMPS
1
0
1
0
1
0
FLOAT VOLTAGE
RECHARGE THRESHOLD
PRECONDITION THRESHOLD
MAXIMUM CHARGE CURRENT
PRECONDITION CURRENT
C/10 CURRENT
8062 F01
8062 F02
LTM8062
9
8062f