TOP242-250
VC
CONTROL (C)
0
DRAIN (D)
INTERNAL
SUPPLY
ZC
1
SHUNT REGULATOR/
ERROR AMPLIFIER
-
+
+
5.8 V
4.8 V
-
SOFT START
5.8 V
IFB
INTERNAL UV
COMPARATOR
CURRENT
LIMIT
ADJUST
VI
(LIMIT)
SOFT
START
ON/OFF
÷
8
SHUTDOWN/
AUTO-RESTART
-
+
VBG + VT
EXTERNAL
CURRENT LIMIT (X)
STOP LOGIC
CURRENT LIMIT
COMPARATOR
LINE-SENSE (L)
1V
HYSTERETIC
THERMAL
SHUTDOWN
VBG
OV/UV
LINE
SENSE
DCMAX
STOP SOFT-
START
DMAX
DCMAX
CLOCK
HALF
FREQ.
SAW
-
+
S
R
Q
CONTROLLED
TURN-ON
GATE DRIVER
FREQUENCY (F)
OSCILLATOR WITH JITTER
LEADING
EDGE
BLANKING
PWM
COMPARATOR
RE
LIGHT LOAD
FREQUENCY
REDUCTION
SOURCE (S)
PI-2639-060600
Figure 2a. Functional Block Diagram (Y, R or F Package).
VC
CONTROL (C)
0
ZC
1
DRAIN (D)
INTERNAL
SUPPLY
SHUNT REGULATOR/
ERROR AMPLIFIER
+
5.8 V
4.8 V
-
+
-
SOFT START
5.8 V
IFB
VI
(LIMIT)
INTERNAL UV
COMPARATOR
CURRENT
LIMIT
ADJUST
SOFT
START
ON/OFF
÷
8
SHUTDOWN/
AUTO-RESTART
STOP LOGIC
-
+
VBG + VT
CURRENT LIMIT
COMPARATOR
MULTI-
FUNCTION (M)
VBG
OV/UV
HYSTERETIC
THERMAL
SHUTDOWN
LINE
SENSE
DCMAX
STOP SOFT-
START
DMAX
DCMAX
CLOCK
CONTROLLED
TURN-ON
GATE DRIVER
SAW
-
+
S
R
Q
OSCILLATOR WITH JITTER
LEADING
EDGE
BLANKING
PWM
COMPARATOR
RE
LIGHT LOAD
FREQUENCY
REDUCTION
SOURCE (S)
PI-2641-061200
Figure 2b. Functional Block Diagram (P or G Package).
M
12/04
3
POWERINT [ POWER INTEGRATIONS, INC. ]
