Datasheet

7
LT1571 Series
–
+
–
+
–
+
–
+
–
+
–
+
BAT
0.2V
1.5V
V
BAT
V
C
GND
SLOPE
COMPENSATION
R2
R3
C1
PWM
B1
CA2
–
+
–
+
CA1
–
+
A11
VA
+
80mV
+
+
4V
V
REF
2.465V
V
REF
SHUTDOWN
200kHz/500kHz
OSCILLATOR
S
R
R
R1
1k
R7
R6
11k
R5
2k
R4
R
S1
I
BAT
I
BAT
V
BAT
I
PROG
I
VA
V
CC
V
CC
V
C
BOOST
V
IN
SW
C1
L1
D2
D1
SENSE
BAT
BATTERY
BAT2
(LT1571-2,
LT1571-5
ONLY)
V
FB
(LT1571-1
ONLY)
SELECT
(LT1571-2,
LT1571-5
ONLY)
1571 BD
PROG
CAP
FLAG
R
PROG
C
PROG
I
PROG
75k
I
PROG
I
BAT
= 500µA/A
Q
SW
–
+
E6
+
I
VA
4
NOTES: LT1571-2: R4 = 7.1k, R7 = 30.24k
LT1571-5: R4 = 3.33k, R7 = 8.62k
LT1571-1: 200kHz, V
FB
PIN FOR ADJUSTABLE
BATTERY VOLTAGE (V
FB
PIN IS NOT INTERNALLY
CONNECTED TO THE RESISTORS)
LT1571-2: 200kHz, PRESET 8.2V CELL
(SELECT PIN OPEN) OR 8.4V (SELECT PIN GROUNDED)
LT1571-5: 500KHz, PRESET 4.1V CELL
(SEECT PIN OPEN) OR 4.2V (SELECT PIN GROUNDED)
I
V
R
BAT
PROG
=






2 465
2000
.
•
D3
BLOCK DIAGRA
W