UC384XA - UC284XA
Figure 18. Under Voltage Lockout.
7
ON/OFF COMMAND
TO REST OF IC
V
i
I
CC
UC3842A UC3843A
UC3844A UC3845A
V
ON
V
OFF
16V
10V
8.4V
7.6V
<17mA
<0.5mA
V
OFF
V
ON
V
CC
D95IN346mod
Figure 19. Current Sense Circuit.
ERROR
AMPL.
I
S
COMP
R
R
S
C
CURRENT
SENSE
5
GND
1
2R
R
1V
3
CURRENT
SENSE
COMPARATOR
D95IN347
Peak current (i
s
) is determined by the formula
1.0V
I
Smax
≈
------------
R
S
A small RC filter may be required to suppress switch transients.
Figure 20. Slope Compensation Techniques.
V
REG
R
T
I
S
R
SLOPE
R
1
R
S
R
T
/C
T
C
T
I
SENSE
8
V
REG
R
T
8
4
I
S
R
SLOPE
R
T
/C
T
C
T
I
SENSE
4
3
5
GND
R
S
R
1
3
5
GND
D95IN348
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