TOP242-250
Pin Functional Description
DRAIN (D) Pin:
High voltage power MOSFET drain output. The internal
start-up bias current is drawn from this pin through a switched
high-voltage current source. Internal current limit sense point
for drain current.
CONTROL (C) Pin:
Error amplifier and feedback current input pin for duty cycle
control. Internal shunt regulator connection to provide internal
bias current during normal operation. It is also used as the
connection point for the supply bypass and auto-restart/
compensation capacitor.
LINE-SENSE (L) Pin: (Y, R or F package only)
Input pin for OV, UV, line feed forward with DC
MAX
reduction,
remote ON/OFF and synchronization. A connection to SOURCE
pin disables all functions on this pin.
EXTERNAL CURRENT LIMIT (X) Pin: (Y, R or F package
only)
Input pin for external current limit adjustment, remote
ON/OFF, and synchronization. A connection to SOURCE pin
disables all functions on this pin.
MULTI-FUNCTION (M) Pin: (P or G package only)
This pin combines the functions of the LINE-SENSE (L) and
EXTERNAL CURRENT LIMIT (X) pins of the Y package
into one pin. Input pin for OV, UV, line feed forward with
DC
MAX
reduction, external current limit adjustment, remote
ON/OFF and synchronization. A connection to SOURCE pin
disables all functions on this pin and makes
TOPSwitch-GX
operate in simple three terminal mode (like
TOPSwitch-II).
Y Package (TO-220-7C)
Tab Internally
Connected to
SOURCE Pin
7
D
5
F
4
S
3
X
2
L
1
C
FREQUENCY (F) Pin: (Y, R or F package only)
Input pin for selecting switching frequency: 132 kHz if
connected to SOURCE pin and 66 kHz if connected to
CONTROL pin. The switching frequency is internally set for
fixed 132 kHz operation in P and G packages.
SOURCE (S) Pin:
Output MOSFET source connection for high voltage power
return. Primary side control circuit common and reference point.
+
R
LS
2 MΩ
V
UV
= I
UV
x R
LS
V
OV
= I
OV
x R
LS
For R
LS
= 2 MΩ
V
UV
= 100 VDC
V
OV
= 450 VDC
DC
MAX
@100 VDC = 78%
DC
MAX
@375 VDC = 38%
C
DC
Input
Voltage
D
L
CONTROL
S
X
R
IL
12 kΩ
For R
IL
= 12 kΩ
I
LIMIT
= 69%
See Figure 54b for
other resistor values
(R
IL
) to select different
I
LIMIT
values
-
Figure 4. Y/R/F Pkg Line Sense and Externally Set Current Limit.
+
V
UV
= I
UV
x R
LS
V
OV
= I
OV
x R
LS
R
LS
2 MΩ
DC
Input
Voltage
For R
LS
= 2 MΩ
V
UV
= 100 VDC
V
OV
= 450 VDC
DC
MAX
@100 VDC = 78%
DC
MAX
@375 VDC = 38%
C
D
M
CONTROL
-
S
PI-2509-040501
Figure 5. P/G Package Line Sense.
P Package (DIP-8B)
G Package (SMD-8B)
M
S
S
C
R Package (TO-263-7C)
F Package (TO-262-7C)
+
For R
IL
= 12 kΩ
I
LIMIT
= 69%
For R
IL
= 25 kΩ
I
LIMIT
= 43%
See Figures 54b, 55b
and 56b for other resistor
values (R
IL
) to select
different I
LIMIT
values.
C
1
2
3
4
8
7
S
S
DC
Input
Voltage
R
IL
D
M
CONTROL
5
D
123 4 5
CL X S F
7
D
PI-2724-010802
-
S
PI-2517-022604
Figure 3. Pin Configuration (top view).
Figure 6. P/G Package Externally Set Current Limit.
4
M
12/04
PI-2629-092203
POWERINT [ POWER INTEGRATIONS, INC. ]
