Datasheet
LM5001
VIN
RT
EN
GND
SW
FB
COMP
VCC
V
IN
= 16V ± 42V
V
OUT
= 5V
I
OUT
= 1A
T1
L
PRI
= 160 éH
8:3:2
C1
4.7 éF
VCC
VCC
C6
100éF
D1
D2
R1
60.4k
R2
6.04k
R3
52.3k
LM431
R8
4.99k
C5
0.1 PF
C2
1 éF
C3
1 éF
R10
2.20k
R9
2.20k
R4
249
R6
47
R7
10k
C4
1 éF
R5
560
LM5001
VIN
RT
EN
GND
SW
FB
COMP
VCC
V
IN
= 16V ± 42V
V
OUT
= 5V
I
OUT
= 1A
T1
L
PRI
= 160 PH
8:3:2
C1
4.7 PF
C3
1 PF
VCC
VCC
C4
100 PF
D1
D2
C5
220 pF
C6
4700 pF
R1
60.4k
R2
6.04k
R3
52.3k
R4
13.0k
R5
10.2k
R6
3.40k
EN
SYNC
C2
100 pF
C7
10 PF
R7
100k
LM5001
,
LM5001-Q1
www.ti.com
SNVS484G –JANUARY 2007–REVISED APRIL 2014
Typical Applications (continued)
Figure 18. Non-Isolated Flyback
8.2.2 Isolated Flyback
The Isolated Flyback converter (Figure 19) utilizes a 2.5 V voltage reference (LM431) located on the isolated
secondary side for the regulation setpoint. The LM5001 internal error amplifier is disabled by grounding the FB
pin. The LM431 controls the current through the opto-coupler LED, which sets the COMP pin voltage. The R4
and C3 network boosts the phase response of the opto-coupler to increase the loop bandwidth. The output is 5 V
at 1 A and the input voltage ranges from 16 V to 42 V. The switching frequency is set to 250 kHz.
Figure 19. Isolated Flyback
8.2.3 Boost
The Boost converter (Figure 20) utilizes the internal voltage reference for the regulation setpoint. The output is 48
V at 150 mA, while the input voltage can vary from 16 V to 36 V. The switching frequency is set to 250 kHz. The
internal VCC regulator provides 6.9 V bias power, since there isn’t a simple method for creating an auxiliary
voltage with the boost topology. Note that the boost topology does not provide output short-circuit protection
because the power MOSFET cannot interrupt the path between the input and the output.
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