Datasheet

9
LTC4065/LTC4065A
4065fb
SI PLIFIED
W
BLOCK DIAGRA S
W
Figure 1b. LTC4065A Block Diagram
–
+
–
+
–
+
–+
–+
2
+
MP
M2
×1
M1
×1000
V
CC
V
CC
R1
R2
ENABLE
4V
R3
R4
R5
2.9V
CHRG
6
PROG
1
GND
4056 F01b
R
PROG
BAT
1V
PROG
C/10
C2
C3
0.1V
1.2V
V
BAT
+ 80mV
3.6V
0.1V
D2
D3
D1
T
DIE
115°C
1.2V
–+
REF
CA
MA
LOBAT
–
+
C1
–+
VA
5
ACPR
3
4
BAT
LOGIC COUNTER
OSCILLATOR
SHUTDOWN
CHARGE CONTROL
–
+
TA
OPERATIO
U
The LTC4065 is a linear battery charger designed primarily
for charging single cell lithium-ion batteries. Featuring an
internal P-channel power MOSFET, the charger uses a
constant-current/constant-voltage charge algorithm with
programmable current. Charge current can be programmed
up to 750mA with a final float voltage accuracy of ±0.6%.
The CHRG open-drain status output indicates if C/10 has
been reached. No blocking diode or external sense resistor
is required; thus, the basic charger circuit requires only
two external components. The ACPR pin (LTC4065A)
monitors the status of the input voltage with an open-drain
output. An internal termination timer and trickle charge
low-battery conditioning adhere to battery manufacturer
safety guidelines. Furthermore, the LTC4065 is capable of
operating from a USB power source.
An internal thermal limit reduces the programmed charge
current if the die temperature attempts to rise above a
preset value of approximately 115°C. This feature protects
the LTC4065 from excessive temperature and allows the
user to push the limits of the power handling capability of
a given circuit board without risk of damaging the LTC4065
or external components. Another benefit of the LTC4065
thermal limit is that charge current can be set according to