LTC4052-4.2_15 Datasheet, PDF (5/12 Pages) Linear Technology – Lithium-Ion Battery Pulse Charger with Overcurrent Protection

LTC4052-4.2
PI FU CTIO S
A series RC network from the GATE to the V_IN pin is
required to control the slew rate at the V_IN pin when the
switch is turned on or off. The slew rate control prevents
excessive current from the capacitor usually located in the
wall adapter from flowing into the battery when the pass
transistor turns on.
BAT (Pin 8): Battery Sense Input Pin. An internal resistor
divider presets the final float voltage to 4.2V. If the BAT pin
drops below 4.05V after the charge cycle has ended, the
timer resets and a new charge cycle begins. This pin is
clamped to 4.7V if the battery is disconnected while
charging.
BLOCK DIAGRA
45mV
V_IN 3
+
BAT
–
GND 4
TIMER 5
OSCILLATOR
CHRG 6
40µA
ACPR
2
100ms ^SLEEP
I_MAX
FILTER
CHARGE
PUMP
TRIPLER
TRICKLE FAST
CLK
V_MIN
STOP
C/10
LOGIC
+
TIMERS
V_RECHRG
V_FLOAT
1_–05m₊V
V_IN
24mA
10mΩ
1 SENSE
7 GATE
8 BAT
THERMAL
SHUTDOWN
TEMP
REFERENCE
1.23V
V_MAX
1.23V
4052 BD
405242f
5