MAX5069 Maxim Integrated, MAX5069 Datasheet - Page 13

• Manufacturer Part Number: MAX5069
• Description: High-Frequency / Current-Mode PWM Controller with Accurate Oscillator and Dual FET Drivers
• Manufacturer: Maxim Integrated

Figure
For example:
High-Frequency, Current-Mode PWM Controller
with Accurate Oscillator and Dual FET Drivers
6. Secondary-Side, Regulated, Isolated Power Supply
R
I
C1
1
≅
V
=
IN
R2
225
C2
C3
C4
C5
24
R3
R4
______________________________________________________________________________________
36
V x
µ
500
V
A
FLTINT
V
REG5
RT
DT
SCOMP
−
CC
+
ms
4 7
AGND
12
.
90
µ
V
C1
F
µ
MAX5069B
A
PGND
IN
=
R1
=
225
COMP
76
UVLO/EN
µ
k
NDRVB
NDRVA
A
Ω
HYST
C6
CS
R5
FB
R6
R
R7
HYST
R8
R9
To minimize power loss on this resistor, choose a high-
er value for R1 than the one calculated above (if a
longer startup time can be tolerated).
The above startup method applies to a circuit similar to
the one shown in
winding has the same phase as the secondary wind-
ings. Thus, the voltage on the tertiary winding at any
given time is proportional to the output voltage. The
minimum discharge time of C1 from 22V to 10V must
be greater than the soft-start time (t
Q1
R10
R11
Q2
V
CC
MAX8515
PS2913
Figure
1. In this circuit, the tertiary
C10
R12
C8
SS
).
V
R13
R14
OUT
C7
13