Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
VI-200 and VI-J00 Family Design Guide
Rev 3.4
vicorpower.com
Page 56 of 97
Apps. Eng. 800 927.9474
800 735.6200
input and allows for remote disabling of the outputs of
2-up and 3-up FlatPACs.
BUS-OK.
An internal replica of BUS-OK is wired to the
GATE IN input of all internal Driver modules. The modules
will be disabled (no DC output) during initial power-up of
the FlatPAC until the internal DC input bus voltage to the
DC-DC converters is sufficient to support fully-loaded
operation. The BUS-OK status output reflects the status of
this inhibit function. This same logic circuit will shut down
the converters when the internal DC bus voltage is
insufficient to support proper loaded operation. This shut
down will occur during normal power down, AC line
dropouts of duration exceeding the hold-up time, or
internal faults causing the internal DC bus voltage at the
input of the converters to collapse.
AC-OK.
This output is provided primarily as an advance
warning of a potential DC BUS-OK shut down due to loss
of AC line or an internal fault. A minimum advance
warning time of 5 ms is provided at 90 Vac and full load.
MOD-DIS+, MOD-DIS–
The Module Disable function will disable the output(s) of
the 2-up and 3-up FlatPACs. The supply is disabled by
applying current to the MOD-DIS+ / MOD-DIS– input. The
minimum input current for disabling the supplies is 1 mA.
The maximum allowable current is 30 mA.
ELECTRICAL CONNECTIONS
Status output pairs AC-OK+, AC-OK– and BUS-OK+,
BUS-OK– are the collectors (+) and emitters (–) of NPN
optoisolator output transistors (one optoisolator per status
signal). The collector terminals AC-OK+ and BUS-OK+ of
the optocouplers, in a typical application, can be
connected via current limiting resistors to a source no
greater than 70 Vdc. These resistors should limit the
maximum current to the optocoupler output transistors to
1.5 mA. The emitter terminals AC-OK– and BUS-OK– are
connected to the return of the external source. The status
OK condition will set the optocoupler output transistors in
saturation and are capable of sinking up to 1.5 mA with a
Vce saturation voltage of 0.4 V. Users should be cautioned
that although the output of the FlatPAC can be used as
the pull-up source, shortly after BUS-OK changes from OK
(saturated) to NOT OK (high Z), the pull-up voltage will be
shut down. It is thus advisable to provide a capacitive
reservoir, if the pull-up source is one of the FlatPAC’s
outputs, in order to maintain the pull-up potential after
loss of DC current output. Use edge sensing logic to
detect assertion of logic outputs, or a separate source of
bias supply voltage (i.e., backup batteries) to provide a
safe pull-up voltage source regardless of the AC line status.
MOD-DIS Input.
Apply a current of 1 – 30 mA to disable
output. Forward voltage drop of internal opto diode is
1.65 V max. at 30 mA max.
AC-OK and BUS-OK Status Outputs.
Outputs low when
OK. Vce sat. = < 0.4 V @ 1.5 mA. Maximum external
pullup is 70 Vdc. AC-OK and BUS-OK signals are isolated
and can have different reference levels.
18. AC Input Power System (FlatPAC Family)
MOD-DIS –
MOD-DIS +
AC-OK –
AC-OK +
BUS-OK –
BUS-OK +
Internal
Supervisory
Circuits
(Optocouplers)
AC Mains
Earth Ground
L1
L2/N
GND
2-Up
and
3-Up
1-Up
Figure 18–1 —
AC mains and supervisory connections
NOTE: Product is internally fused
Figure 18–2
— External supervisory functions (2-up and 3-up
models only)
V
+
r
AC-OK
+
–
1.5 mA
max.
V
+
r
BUS-OK
+
–
30 mA max.
Disable
MOD-DIS
V
+
+
–
1.5 mA
max.
FlatPAC
Summary of Contents for VI-200 Series
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