ltc1871ems-trpbf Linear Technology Corporation, ltc1871ems-trpbf Datasheet - Page 33

• Manufacturer Part Number: ltc1871ems-trpbf
• Description: Wide Input Range, No Rsense Current Mode Boost, Flyback And Sepic Controller
• Manufacturer: Linear Technology Corporation

TYPICAL APPLICATIONS
54.9k
1%
R2
8.2nF
C
C
47pF
1V/DIV
C1
12k
C2
R
V
4.7nF
C
OUT
C1
Q1
154k
1%
R3
R6
750Ω
4.5V to 28V Input, 5V/2A Output SEPIC Converter with Undervoltage Lockout and Soft-Start
49.9k
1%
R4
100Ω
115k
R5
1%
Soft-Start
R1
R
162k
1%
1ms/DIV
T
C
C
C
C
C
1
2
3
4
5
IN1
IN2
OUT1
OUT2
VCC
C2
1μF
X5R
RUN
I
FB
FREQ
MODE/SYNC
1A/DIV
TH
, C
:
:
100mV/DIV
(DC)
I
:
:
OUT
DC
: TAIYO YUDEN GMK325BJ225MN
LTC1871
AVX TPSE226M035R0300
SANYO 6TPB330M
TAIYO YUDEN JMK325BJ226MN
LMK316BJ475ML
V
(AC)
2.2A
0.5A
OUT
INTV
SENSE
GATE
NOTES:
GND
1871 TA02b
V
1. V
2. SOFT-START dV
CC
IN
Load Step Response at V
V
IN
IN
10
9
8
7
6
UVLO
UVLO
+
–
= 4.17V
= 3.86V
C
4.7μF
10V
X5R
VCC
OUT
250μs/DIV
/dt = 5V/6ms
D1:
L1, L2: BH ELECTRONICS BH510-1007 (*COUPLED INDUCTORS)
M1:
Q1:
1A/DIV
C
2.2μF
35V
X5R
IN1
100mV/DIV
(DC)
I
OUT
IN
+
INTERNATIONAL RECTIFIER 30BQ040
SILICONIX/VISHAY Si4840
PHILIPS BC847BF
V
(AC)
2.2A
0.5A
= 28V
OUT
C
22μF
35V
IN2
1871 TA02d
Load Step Response at V
L1*
•
M1
2.2μF
C
25V
X5R
×3
DC
•
L2*
250μs/DIV
D1
+
C
330μF
6.3V
OUT1
IN
= 4.5V
LTC1871
1871 TA02a
C
22μF
6.3V
X5R
1871 TA02c
OUT2
GND
V
4.5V to 28V
V
5V
2A
(3A TO 4A PEAK)
IN
OUT
33
1871fe