Vicor VI-J00 Family DC-DC Converters and Configurable Power Supplies - Manual (Page 39)

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 3.5 vicorpower.com
Page 38 of 98
Apps. Eng. 800 927.9474 800 735.6200
13. AC Input Harmonic Attenuator Module (HAM)
GATE IN (BAMD) Pin. The Gate In pin is an interface pin
to the Gate Out pin of a HAMD or BAMD depending on
configuration. The user should not make any other
connection to this pin.
GATE OUT Pin. The Gate Out pin is a synchronization pin
for HAMD/BAMD arrays; the user should not make any
other connection to this pin.
+OUT and -OUT Pin. Connect the +OUT of the HAM to
the +IN of the respective Vicor DC-DC converters with the
recommended fuse. Connect the -OUT of the HAM to the
-IN of the converters. In addition, an external hold-up
capacitor of 1,000 µF with a minimum voltage rating of
450 Vdc, is required (across the output of the HAM) for
16 ms ride through time at full power (500 µF for half
power, etc). This capacitor must be in close proximity to
the HAM. Do not exceed 3,000 µF of total output
capacitance. Lower values of capacitance may be used for
reduced hold up requirements, but not less than 500 µF.
Lower capacitance values may degrade power factor
specifications.
Auxiliary Supply (A/S) Pin. The HAM provides a low
voltage non isolated output Auxiliary Supply (A/S) that
may be used to power primary side control and
monitoring circuitry. This output is 19 – 23 Vdc,
referenced to -OUT, at 3 mA max. Do not overload or
short this output as the HAM will fail. A typical use for
A/S is to power an optical coupler that isolates the Power
OK signal (Figure 13–6).
Enable Output (E/O) Pin. The Enable Output (E/O) is
used to inhibit the DC-DC converters at start up until the
hold up capacitors are charged, at which time Enable is
asserted high (open state, Figure 13–8). If the AC line
fails, E/O goes low when the DC output of the HAM
drops below 195 Vdc.
E/O must be connected to the Gate Input of all VI-26x and
VI-J6x drivers (Figure 13–4); failure to do so may cause the
converters to toggle on and off. It is not necessary to
connect this pin to boosters as they are controlled by their
respective driver. If an external load is connected directly
to the output of the HAM, do not apply the load until the
output hold up capacitor(s) are fully charged.
The E/O pin ancillary circuitry illustrated in Figures 13–4 and
13–5 provides transient immunity. The illustrated circuitry is
the minimum required, see Figures 13–4 and 13–5.
Power OK (P/OK) Pin. Power OK is a monitor signal that
indicates the status of the AC mains and the DC output
voltage of the HAM. P/OK is asserted (active low) when
the output bus voltage is within normal operating range
20 – 25 ms after DC-DC converters are enabled by the
E/O signal of the HAM. This provides sufficient time for
the converters to turn on and their output(s) to stabilize
prior to P/OK being asserted (Figure 13–9). For momentary
interruptions of AC power, the HAM will provide at least
16 ms of ride through or hold up time (with 1,000 µF
output capacitor). On loss of power or brownout, (when
the HAM output voltage drops below 230 Vdc) the P/OK
signal will go to an open circuit state (see Figure 13–7),
signaling an impending loss of input power to the
converter modules. P/OK will provide power fail warning
at least 1 ms prior to converter shut down. When the
HAM output voltage drops below 195 Vdc the converters
are disabled via Enable Output (E/O).
NOTE: Acoustic Noise. Audible noise may be emitted
from the module under no load, light load, or
dynamic loading conditions. This is considered
normal operation of the module.
SAFETY NOTES
Each HAM, HAMD or BAMD module must be
preceded by a safety agency recognized fast-blow
10A 3AG fuse.
The HAM is not isolated from the line – either input
or output; a line isolation transformer must be used
when making scope measurements. HAMs do not
provide input to output isolation. Differential probes
should be used when probing the input and output
simultaneously to avoid destructive ground loops.
PROTECTIVE FEATURES
Over Temperature Shut Down. The HAM is designed to
shut down when the temperature of the baseplate
exceeds 90°C. Do not operate the HAM above its
maximum operating temperature of 85°C.
Short Circuit Protection. The HAM contains output short
circuit protection. Operation of this function does not
clear the input fuse and the output will resume normal
operation after removal of the fault.
A short period of time may be required to allow for
cooling of an internal temperature sensor.
Output Over Voltage Protection. The HAM contains
output over voltage protection. In the event the output
voltage exceeds approximately 420 Vdc, the boost will
decrease to maintain 420 Vdc on the output. When the
peak of the AC line exceeds 420 V (approximately
293 Vac) the boost will have been reduced to zero and
the E/O line will be pulled low shutting down the
converters. Beyond this the protection circuit will be
enabled and the output voltage will decrease.