4.4.15 Output Good Signal
Typical applications of Output Good Signal
Output Good Signal is an open collector output, referenced to COM potential, indicating the status of
the power supply output. While the power supply operates normally, the Output Good is low (0~0.8V).
When the power supply output is disabled due to activated OVP, OTP or FOLD protection, or by OUT
set to off, or by ac ON/OFF set to off, then the output signal stops conducting. The maximum sink
current is 10mA and the maximum voltage is 40VDC.
1. In multiple power supply systems, it is possible to disable all the units when a critical unit fails. Refer
to Fig 4-15 for typical connection diagram.
2. Hierarchical structure in multiple supply systems:It is possible to define a hierarchy in multiple supply
systems by enabling any N+1 unit by the Output Good signal of the N unit. In this structure, failure of
the N unit will cause all the following units to be disabled. Refer to Fig 4-16 for typical connections
diagram.
CAUTION
The Output Good Signal is referenced to the COM potential, therefore pay attention NOT to
short it to another potential as it may damage the unit.
Fig. 4-15: Disabling multiple supply systems.
Fig. 4-16: Hierarchical structure in
multiple supply systems.
- V
- V
For 60V output models, use a Zener diode to limit the
Output Good voltage below 40V. The resistor and Zener
power rating must be greater than the maximum actual
power dissipation.
( )
*
( )
*
( )
*
( )
*
- V
COM
COM
PCn
PCn
PC1
PC1
I = 5mA
COM
+V
+V
+V
ON/OFF
OUT.GOOD
ON/OFF
ZUP #
Critical
ZUP
Unit # 1
ZUP #
n
n
OUT.GOOD
OUT.GOOD
OUT.GOOD
COM
- V
COM
- V
COM
PC1-A
PC2-A
PC1-B
PC( -1)-B
n
+V
+V
+V
ON/OFF
ON/OFF
ON/OFF
ZUP # 1
ZUP # 2
ZUP #
n
37
