Specifications
19
POWERCASSETTE FRONT-END
OPERATING MANUAL
SIGNAL
PINS
DESCRIPTION
Enable 7
A logic LO or short to Pin 9 enables (turns on) the unit. A logic HI or
open inhibits (turns off) the unit. This input is referenced to - Sense,
Pin 9. This pin must be activated to a logic LO or short for the
PowerCassette to operate.
15.0 DESCRIPTION OF CONTROL AND SUPERVISORY SIGNALS
Current Share 18
This analog signal is used to connect to the same pin of another
identical PowerCassette to share output currents. Output currents
between units are shared within an accuracy of 10% of full load
current over a 50% to 100% load range. This signal is referenced to
- Sense, Pin 9.
A logic LO indicates that the unit is operating properly with output
voltage in its controllable range. A logic HI indicates output failure.
The equivalent circuit is an NPN transistor collector with a 10K ohm
resistor to +5V. This signal is referenced to - Sense, Pin 9.
DC Power Good 14
External Trim
16
This is the connection for the output external trim. The voltage can
be adjusted over a ±5% range from nominal using the external
circuits shown in Figure 6.
Standby Supply
20
This is a +5VDC, ¼A auxiliary output for powering external control or
other circuits. The return is the Standby Return, Pin 21. This output
is not controlled by the Enable or Inhibit inputs.
8 & 9
± Sense
These remote sense leads should be connected as a twisted pair to
the respective + and - load points to provide regulation at the point of
load. The correct polarities must be maintained.
Inhibit
10
A logic LO or short to Pin 9 turns off the output; a logic HI or open at
this pin turns on the output. This input is referenced to -Sense,
Pin 9.
Overtemperature
Warning
17
A logic HI at this output indicates an overtemperature condition
inside the unit. The HI occurs a few milliseconds before the unit
shuts down. This output is referenced to -Sense, Pin 9.
AC Power Fail
15
A logic LO indicates the AC power is present; a logic HI indicates
AC power failure. The signal goes HI 4 msec. before the output goes
out of regulation and stays HI typically for 15 msec. The equivalent
circuit is an NPN transistor collector with a 10K ohm resistor to +5V.
This signal is referenced to - Sense, Pin 9.