MIL-COTS PFC Front End

Rev 1.3

vicorpower.com

Page 7 of 9

01/2014

800 927.9474

Granite Power

GP-MPFC1H21

Not Recommended for New Designs

PFC Brick

Pin function/description

LINE/NEUTRAL (Pins 1 & 4)

Connect single phase AC mains from appropriate EMI filter to

these pins via a 15 Amp 250V fuse. Connect the output of the

filter to the LINE and NEUTRAL pins of the PFC Brick. To

meet MIL-STD-461E/F requirements, an EMI filter between the

AC input and PFC Brick similar to that shown in Fig. 4

is required.

N/C (Pins 2, 3, 6, 7)

No Connect. Do not connect to these pins.

MOD ENABLE (Pin 8)

Connect this pin to the down stream Vicor DC/DC converter(s)

PC pin as shown in Figure 2. The external circuitry between the

MOD ENABLE pin and PC pin shown in the figure must be

used to ensure proper operation. During power up, the MOD

ENABLE pin is held low until the PFC output is up and

regulating. Any fault with the PFC output will cause this pin to

go low and held low until the fault is cleared. If an external load

is connected directly to the output of the PFC Brick, do not

apply the load until the holdup capacitors are fully charged.

+/- OUTPUTS (+ Pin 9, - Pin 5)

Connect the +OUT pin to the +IN of the respected Vicor DC/DC

converter. Connect the -OUT pin to the -IN of the respected

Vicor DC/DC converter. In addition, external hold-up capacitor

of 1500uF with a minimum voltage rating of 450VDC is

required across the +OUT and –OUT pins. This capacitor must

be in close proximity of the PFC Brick. Do not exceed 3000uF

of total output capacitance.

Safety Features:

Over Temperature Shut Down:

The PFC Brick is designed to shut down if the baseplate

temperature (measured in the center of the baseplate) exceeds

100°C. Certain line and load conditions dictate lower maximum

temperatures as indicated in Figure 1.

Exceeding the power/temperature limits shown in Figure 1 or

the maximum 100°C limit may result in permanent module

failure. We do not guarantee module survival if the temperature

limits are exceeded.

The addition of the thermal safety components shown in Figure

2 should be used if the application requires operation at input

voltage and output power where a lower baseplate temperature

is required.

Output Over Voltage Protection:

In the event the PFC output exceeds approximately 415VDC, the

boost converter will momentarily shut down to keep the PFC

output below 415VDC. The MOD Enable pin will go low and

stay low until the PFC output returns to its normal

operating range.

Safety Notes:

The PFC Brick is not isolated from the AC mains. An isolation

transformer must be used when making scope measurements.

The PFC Brick does not provide input to output isolation.

Differential probes should be used to avoid destructive ground

loops.

DESCRIPTION