Artesyn iHP - AVS Protection Modes; AVS Protection over Current Response

iHP Manual 77 | P a g e
iHP Owners Manual
4.5.1.1 AVS Protection Modes
When the supply is in AVS mode, the output is protected against over current, short circuit, over voltage, and
under voltage faults. The behavior of the supply during an over current fault or short circuit fault is
dependent on whether IREF is set to constant current behavior or latch behavior. In constant current mode,
the module will attempt to operate at a constant current level while reducing the output voltage and in latch
mode the supply shut off. In the event of an overvoltage and under voltage faults the supply will shut down.
Please refer to Section 8 on how to clear the fault and power up the module after fault.
4.5.1.1.1 AVS Protection Over Current Response
Over current response mode will be set by Module Command 52h (OC_RESPONSE_TYPE). The two types of
response are Constant Current and Latch. The over current level will be based on Module Command 4Dh
OC_FAULT_LIMIT_MULTIPLIER setting.
Module Command 4Dh OC_FAULT_LIMIT_MULTIPLIER range is 50% to 105%
When 52h set to Constant Current Response, the module will enter constant current mode when load current
reaches the IREF value (B2h). The output voltage will decrease to maintain the load current at the current limit.
No fault reporting occurs during this condition.
The module will revert to normal operation when load current becomes less than IREF value (B2h).
The constant current setting, IREF, is dependent on the Vout setting (VREF).
When the:
 Vo (VREF) is below or equal to the nominal voltage
IREF = (Inominal) * (OC_FAULT_LIMIT_MULTIPLIER)
 Vo (VREF) is above the nominal voltage, the IREF, value is automatically reduced to maintain the supply
within the maximum peak power of the module
IREF = [ (Pnominal) * (OC_FAULT_LIMIT_MULTIPLIER)] / VREF
Note that the CC setting level, IREF, will be reflected on IREF (Module Command B2h).
When 52h set to Latch Type, the module will shut down when the output current reaches the latch level for
500msec and a fault status will be reported.
The Latch Current Level setting is dependent on the Vout setting (VREF).
When the:
 Vo (VREF) is below or equal to the nominal voltage
Latch Current Level = (Inominal) * (OC_FAULT_LIMIT_MULTIPLIER)