P024F048T12AL_15 Datasheet, PDF (10/14 Pages) Vicor Corporation – Non-isolated Regulator

Application Information (continued)
OVP – Overvoltage Protection
The output Overvoltage Protection set point of the P024F048T12AL is
factory preset for 56 V. If this threshold is exceeded the output shuts
down and a restart sequence is initiated. If the condition that causes
OVP is still present, the unit will again shut down. This cycle will be
repeated until the fault condition is removed. The OVP set point may
be set at the factory to meet unique high voltage requirements.
PRM Output Power Versus VTM Output Power
As shown in Figure 17 the P024F048T12AL is rated to deliver 2.5 A
maximum, when it is delivering an output voltage in the range from
26 V to 48 V, and 120 W, maximum, when delivering an output
voltage in the range from 48 V to 55 V. When configuring a PRM for
use with a specific VTM, refer to the appropriate VTM data sheet. The
VTM input power can be calculated by dividing the VTM output power
by the VTM efficiency (available from the VTM data sheet). The input
power required by the VTM should not exceed the output power
rating of the PRM.
2.55
2.50
2.45
2.40
2.35
Safe Operating Area
2.30
2.25
2.20
2.15
~~
0
20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Factorized Bus Voltage (Vf)
Figure 17 — P024F048T12AL rating based on Factorized Bus voltage
The Factorized Bus voltage should not exceed an absolute limit of
55 V, including steady state, ripple and transient conditions. Exceeding
this limit may cause the internal OVP set point to be exceeded.
Parallel Considerations
The PR port is used to connect two PRMs in parallel to form a higher
power array. When configuring arrays, PR port interconnection
terminating impedance is 10 k to SG. See note Page 8 and refer to
Application Note AN002. Additionally one PRM should be designated
as the master while all other PRMs are set as slaves by shorting their
SC pin to SG. The PC pins must be directly connected (no diodes) to
assure a uniform start up sequence. Consult Vicor applications
engineering for applications requiring more than two PRMs.
P024F048T12AL
Adjusting Current Limit
The current limit can be lowered by placing an external resistor
between the I_L and SG ports (see Figure 18 for resistor values). With
the I_L port open-circuit, the current limit is preset to be within the
range specified in the output specifications table on Page 4.
100.00
10.00
1.00
0.5
1
1.5
2
2.5
Desired PRM Output Current Limit (A)
Figure 18 — External resistor value for adjusting current limit
Input Fuse Recommendations
A fuse should be incorporated at the input to the PRM, in series with
the +In port. A fast acting fuse, NANO2 FUSE 451/453 Series 10 A
125 V, or equivalent, may be required to meet certain safety agency
Conditions of Acceptability. Always ascertain and observe the safety,
regulatory, or other agency specifications that apply to your specific
application.
Product Safety Considerations
If the input of the PRM is connected to SELV or ELV circuits, the output
of the PRM can be considered SELV or ELV respectively.
Application Notes
For PRM and VI Chip application notes on soldering, board layout, and
system design please click on the link below:
http://www.vicorpower.com/powerbench/applicationnotes
Applications Assistance
Please contact Vicor Applications Engineering for assistance,
1-800-927-9474, or email at [e-mail].
PRM^® Regulator
Page 10 of 14
Rev 3.2
07/2015
vicorpower.com
800 927.9474