LTC3637_15 Datasheet, PDF (21/26 Pages) Linear Technology – 76V, 1A Step-Down Regulator

TYPICAL APPLICATIONS
4V to 64V Input to –12V Output Positive-to-Negative Regulator
V_IN
4V TO 63V
C_IN
2.2µF
V_IN
SW
LTC3637
RUN V_FB
I_SET
SS
FBO V_PRG1
OVLO V_PRG2
GND
L1
4.7µH
D1
R1
200k
R2
147k
C_IN: KEMET C1210C225M1RAC
C_OUT: AVX 1210YC226MAT
D1: AVX SD3220S100S5R0
L1: COOPER BUSSMANN DR7-4R7-R
C_OUT
22µF
V_OUT
–12V
3637 TA03a
24.5V to 76V Input to 24V Output with 350mA Input Current Limit
V_IN
24.5V TO 76V
C_IN
1µF
R3
806k
R4
11.5k
V_IN
SW
LTC3637
RUN V_FB
I_SET
SS
V_PRG1
FBO OVLO
V_PRG2
GND
L1
22µH
D1
R1
200k
R2
53.6k
V_OUT
C_OUT ^24V
10µF
3637 TA04a
C_IN: TAIYO YUDEN HMK325B7105MN
C_OUT: TDK C3225X7R1H106M
D1: DIODES INC. SBR3U100LP
L1: WÜRTH 7447714220
LTC3637
Maximum Load Current vs Input Voltage
1000
V_OUT = –12V
800
600
400
200
0
0 10 20 30 40 50 60
INPUT VOLTAGE (V)
3637 TA03b
MAXIMUM LOAD CURRENT ≈ ^VIN • ^IPEAK
V_IN + | V_OUT | 2
Maximum Input and Load Current vs Input Voltage
1000
900
800
MAXIMUM
OUTPUT CURRENT
700
600
500
MAXIMUM
400
INPUT CURRENT
300
200
INPUT
CURRENT
LIMIT
≈
V_OUT
•
R4
R3 + R4
100 MAXIMUM LOAD CURRENT ≈ ^VIN • ^R4
2 R3+R4
0
25
35
45
55
65
75
INPUT VOLTAGE (V)
3637 TA04b
For more information www.linear.com/LTC3637
3637fa
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