250W 3" x 5" Convection Cooled AC-
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CURRENT SHARING OPTION – PQC250-XX-DXX
PQC250-XX-Dxx
Refer to ACAN-78
for additional
details
Main Output current share is achieved using “the droop method”. Nominal output voltage is achieved at 50% load and output voltage increases/decreases
approximately ±3% of nominal voltage. This regulation window does not include the additional tolerance due to line, temperature, long term stability etc.
Startup of parallel power supplies is not internally synchronized. If more than 250W combined power is needed, start-up synchronization must be provided
by system using a common PS_ON signal. To account for ±10% full load current sharing accuracy and the reduction in full load output voltage due to
droop, available output power must be derated by 15% when units are operated in parallel. Current sharing can be achieved with or without remote sense
connected to the common load.
ORing protection is available on the PQC250-xxDRT models (see Application notes, ACAN-78 for additional details);
Aux (V2) output can be tied together for redundancy but total combined output power must not exceed 2.5W, external ORing devices are recommended to
Voltage Fluctuation and Flicker
Conducted Emissions EN 55022 Class B
FCC Part 15 Class B
Radiated Emissions CISPR 22 -3 meter Class B
ESD Immunity IEC/EN 61000-4-2 Level 4, Criterion 2
Radiated Field Immunity IEC/EN 61000-4-3 Level 3, Criterion A
Electrical Fast Transient Immunity IEC/EN 61000-4-4 Level 4, Criterion A
Level 3, Criterion A (Com. Mode: 2kV 12 OHM, Diff.
Mode: 1kV, 2 OHM)
Radiated Field Conducted Immunity
Level 3, 10V/m, Criterion A
Magnetic Field Immunity IEC/EN 61000-4-8 Level 3, Criterion A
Voltage dips, interruptions IEC/EN 61000-4-11 Level 3, Criterion B
EMI
CONSIDE
STATUS AND CONTROL SIGNALS
PS_ON All Models This pin must be pulled low (sink current >2mA) to +5V_AUX_RTN to turn on the main output. The +5V_AUX output is independent of the PS_ON
signal, and comes up automatically when the input AC or input DC voltage is applied within their specified operating ranges.
PWR_OK All Models Open collector logic goes high 40-100ms after the main output is within regulation; it goes low at least 2msecs before loss of regulation. Internal
10K pull up to +5V_Aux is provided. Applications using the PWR_OK signal should maintain a minimum load of 5W on the main output.
Options
D1 = Droop
DRT = ORing; Droop; Output Terminal Block
H = DC input2 Link back to Input_Table
PQC= “Power, Quality, Convection Cooled”
(12, 18, 24, 36, 48, 54)
Examples: PQC250-24 = Base 24V Model; no options
PQC250-24D = Base model, 24V Model with Droop Current Share option
PQC250-24DRT= Base model, 24V Model with Droop Current Share, ORing isolation and Terminal Block options
1 not available for 18V model
2
CCC Certification not included for “H” models and 30V models
For optimum EMI performance, the power supply should be mounted to a metal plate grounded to all 4 mounting holes of the power supply. To comply with safety standards,
this plate must be properly grounded to protective earth (see mechanical dimension notes). Pre-compliance testing has shown the stand-alone power supply to comply with
EN55022 class B radiated emissions with a metal enclosure with grounded base plate. See PQC-COVER for details - testing was based on adding a toroid, Fair-
Rite#5961004901 with five turns of both of the output leads. Radiated emission results vary with system enclosure and cable routing paths.