Rainbow Electronics MAX5974D - Manual (Page 13)

MAX5974A/MAX5974B/MAX5974C/MAX5974D
Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers
13
Block Diagrams
DRIVE
R
1A/-0.65A
DEAD-TIME CO
NT
RO
L
11
NDR
V
SS
16 CS
9 CSSC
8 COM
P
5
FB
6 IN
13 EN
14
VC
PGND
DRIVE
R
0.5A/-0.3
A
12
AUXDRV
1
DT
3 15 4
20% <
D
MAX
< 80
%
RT
DCLM
P
FFB
SYN
C
VB
30µA
/
90µA
NDR
V
BLANKIN
G
PULS
E
SS
VC
PGND
FFB COM
P
V CSAVG
DEAD TIME
NDRV
AUXDRV
PO
K
OSCILLATOR
DRIVER LOGI
C
REVERSE
I LIM
LIMIT TURN
S
OFF AUX IMMEDIATEL
Y
PEAK
I LIM
COMP
400m
V
2
DITHER
/
SYN
C
7
GND
10
PGND
VB
50µA
/
-50µA
2V/400m
V
10X
Q
SET
Q CLR
S
COUNT
8
EVENTS
HICCUP LATCH
115ns
BLANKIN
G
5V
REGULATOR
ENABL
E
1.23V
PO
K
VB
THERMAL SHUTDOW
N
UVLO
115ns
BLANKIN
G
R V SS
< 150m
V
REVERSE
I LIM
COM
P
-100m
V
2µA
10µA 2m
A
PO
K
PWM COM
P
R1
2 x R1
VB
S/H
1.52V
VB
VB
g M
VB
SLOP
E
COMPENSATIO
N
LOW-POWER UVLO
V INUVR
= 20V (MAX5974A
)
V INUVR
= 10V (MAX5974B
)
V INUVF
= 7V
MAX5974A MAX5974B