Datasheet

LTC1730-4/LTC1730-4.2
6
sn1730 1730fs
BLOCK DIAGRA
W
PI FU CTIO S
UUU
N-channel MOSFET. This output can sink up to 5mA
suitable for driving an LED.
FAULT (Pin 5): Fault Condition Detection Open-Drain
Output. This output can sink up to 3mA suitable for driving
an external LED. The internal N-channel MOSFET pulls this
pin to ground when either one of the following conditions
is detected:
1. The voltage at the NTC pin is out of the normal operation
range. This usually means the battery pack temperature
is too high or too low. Once the temperature is back to
normal, the FAULT pin becomes high impedance.
2. The BAT pin potential stays below 2.45V for more
than 1/4 of the programmed charge time. When this
condition is detected, the FAULT pin is pulled low and
latched.
CHRG (Pin 6): Refer to LTC1730ES8-4.2
NC (Pins 7, 14): No Internal Connection. Connecting these
pins to ground will help transfer heat from the package.
TIMER (Pin 10): Refer to LTC1730ES8-4.2
NTC/SHDN (Pin 11): Refer to LTC1730ES8-4.2
SEL (Pin 12): 4.1V/4.2V Battery Selection Input. Ground-
ing this pin will set the output float voltage to 4.1V, while
connecting to V
CC
will set the voltage to 4.2V.
GATE (Pin 13): Refer to LTC1730ES8-4.2
BAT (Pin 15): Refer to LTC1730ES8-4.2
+
–
–
+
LOGIC
RECHRGON
C6 C4
40mV
+
–
+
–
C7 C3
–
+
+
–
C8
121mV
C2
+
–
C1
OSCILLATOR CLK
FAULT
V
MIN
I
MAX
STOPC/10
SHDN V
BAT
HOT V
MAX
COLD ACPR
+
–
C9
1.21V
R4
R5
+
–
–
+
C5
100mV
+
–
150mV
+
–
R3
R2
R1
35mA
GATE
BAT
N
SW
NTC/SHDN
TIMER
40µA
N1
Q-PUMP
(3X)
SENSE
0.375R
0.5R
GND
1703 BD
CHRG
V
CC
FAULT
0.125R
ACPR
SEL
4.1V/4.2V