Specifications

12
1-800-927-9474
20-8
Autoranging MegaPAC/Mini MegaPAC Interface Connections (cont)
General Shutdown GSD (J10-12)
The GSD control pin on J10-12 allows simultaneous shutdown of all ConverterPAC outputs.
This pin must be pulled down to less than 0.7V, and will source 13 mA maximum to shut down
all outputs. The GSD pin should be open circuited or allowed to exceed 4.5V when not in use,
or when the outputs are to be enabled. Do not apply more than 8V to this input at any time.
Normal open circuit voltage is 1.5 to 3V with respect to Signal Ground.
AC Power OK (J10-11)
This is an active high TTL compatible signal, and provides a status indication of the AC input
power. It is capable of sinking 20 mA maximum. This signal switches to a TTL “1” when the
high voltage bus exceeds low-line condition during turn-on, and switches to a TTL “0” 3 ms
(typical) before loss of output regulation due to the loss of input AC power. This signal may be
used to warn external control circuits of an impending loss of power.
Auxiliary Vcc +5V/0.3A (J10-9)
The Vcc on J10-9 is an auxiliary 5V regulated power source. It is +5Vdc +/–5% with respect
to Signal Ground, and can supply 300 mA maximum. It is short circuit proof, but if shorted all
outputs will shut down through the Enable/Disable circuitry.
The Auxiliary Vcc is typically used with the Power Good circuitry to provide a pull-up reference
for the outputs of the DC Power Good circuit on a ConverterPAC (Figure 11, below). If
used for this purpose, then the Signal Ground on J10-10 must also be connected to the J3-4
Signal Ground pin of the ModuPAC.
Applications Manual
PFC MegaPAC
1
10
12
Signal Ground
General Shutdown
Enable/Disable Output 1
J10
Enable/Disable Control
1
0
TTL "1" (OFF)
TTL "0" (ON)
A TTL "1" applied to the base of the transistor turns
output OFF. Pin 1 (or Pin 12 for GSD) is pulled Low
with respect to Signal Ground.
9
Vcc
Figure 10.
Enable/Disable
General Shutdown
10K
Signal Ground
AC Power OK
11
+5V
10
J10
2.49K
PN2222
Figure 11.
AC Power OK