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Auxiliary VCC +5V/0.3A (J10-16, 17)
The VCC on J10-16 and J10-17 is an auxiliary 5V regulated power source (see Figure 6 and Connector
Pin Identification on Page 11). It is +5V
DC
(±5%) with respect to Signal Ground, and can supply 300mA
maximum. It is short-circuit proof, but if shorted, all outputs will shut down through the
Enable/Disable circuitry. The Auxiliary VCC typically powers user circuitry or is used with the Power
Good circuitry to provide a pull-up reference for the outputs of the DC Power Good circuit on a
ModuPAC
™
. If used for this purpose, a Signal Ground on J10 must also be connected to the J3-1 Signal
Ground pin of the ModuPAC.
Power Good (J3-3)
The optional Power Good signal on J3-3 is referenced to Signal Ground on J3-1, and indicates the
status of the output voltage. This signal is asserted a TTL “1” when the output voltage is above 95% of
nominal. It is a TTL “0” when the output voltage is below 85% of nominal.
If the Trim option is also used, the Power Good trip points DO NOT track with the trimmed voltage. It
is possible to trim the output below the fixed setpoints of the Power Good circuit and cause a negative
Power Good signal.
Power Good Inverted (J3-2)
This is the inverse of the Power Good signal and is referenced to Signal Ground on J3-1.
Figure 6
Auxiliary VCC
Figure 7
Power Good and VCC
78M05
Auxiliary VCC
16
0.1µF
Signal Ground
J10
15
+5V/300mA
Auxiliary VCC
17
Signal Ground
3
VCC
1
J3
10kΩ
2.49kΩ
2N2222
2.49kΩ
4
Power Good
2
Power Good
ConverterPAC
