MAX15001 Maxim Integrated Products, MAX15001 Datasheet - Page 14

• Manufacturer Part Number: MAX15001
• Description: (MAX15000 / MAX15001) Current-Mode PWM Controllers
• Manufacturer: Maxim Integrated Products

Figure 6 shows a complete circuit of a dual-output
power supply with a telecom voltage range of 36V to
72V. An important aspect of this power supply is that it
is primary-side regulated. The regulation through the
tertiary winding also supplies bias for the MAX15000.
In the circuit of Figure 6, cross-regulation has been
improved (tertiary and 5V outputs) by using chip induc-
tors, L1 and L2, and R7||R12 across C12. R7||R12 pre-
sents enough loading on the tertiary winding output to
allow ±10% load regulation on the 5V output over a
load current range from 150mA to 1.5A (Figure 7).
Current-Mode PWM Controllers with
Programmable Switching Frequency
Figure 6. Primary-Side-Regulated, Dual-Output, Isolated Telecom Power Supply
14
1.37M
51.1k
1%
NOTE: MOSFET N1 = IR IRF7464.
______________________________________________________________________________________
R3
R4
FB_P
+VIN
36V TO 72V
+VIN
-VIN
OPEN
SHDN
C17
22.6k
2.49k
1%
1%
R1
R2
+VIN
1
2
Isolated Telecom Power Supply
JU1
IN
75k
1%
UFLG_PULL
R6
33k
R9
C1
1 F
100V
UFLG
3900pF
0.22 F
100pF
C14
10k
Primary-Side-Regulated,
R13
C7
C9
C16
1 F
35V
C2
1 F
100V
D8
3
4
1
9
2
FB_P
FB
COMP
UVLO/EN
V
UFLG
CC
C12
15 F
35V
MAX15000A
U1
R7
1.2k
NDRV
GND
CS
RT
IN
R12
1.2k
10
8
5
7
6
IN
R8
OPEN
C11
0.22 F
C8
OPEN
R14
14.3k
1%
D7
OPEN
D6
100
4.7
R11
R10
C10
OPEN
OPEN
R15
750
C18
0.1 F
D3
4
L2
Figure 7. Output Voltage Regulation for the Circuit in Figure 6
5
1
6
35 H
2
15T
28T
7
N1 IRF7464
3
4
8
R5
0.600
1%
C19
OPEN
5 T1
3
2
1
9
10
7
5.6
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
8
6
12T
5T
0.15
C6
0.0047 F
250VAC
D2
D1
0.30 0.45 0.60
5V OUTPUT LOAD REGULATION
C5
47 F
25V
C3
68 F
6.3V
0.75
I
OUT
D5
D4
15V/100mA
0.90
(A)
L1
NO LOAD AT 15V
OUTPUT
V
V
1.05
IN+
IN-
= 0V
= 40V
1.20
5V/1.5A
C15
1 F
C13
1 F
1.35
1.50
C4
22 F
6.3V
VOUT2
SGND
VOUT1
SGND