PR036A480T012FP Datasheet, PDF (11/13 Pages) Vicor Corporation – PRM™ Regulator

APPLICATION NOTES
OVP – Overvoltage Protection
The output Overvoltage Protection set point of the PR036A480T012FP is
factory preset for 56 V. If this threshold is exceeded the output shuts down
and a restart sequence is initiated, also indicated by PC pulsing. 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 PR036A480T012FP 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 — PR036A480T012FP 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.
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
10
1
0
0.5
1
1.5
2
2.5
3
Desired PRM Output Current Limit (A)
Figure 18 — Calculated external resistor value for adjusting current limit, actual
value may vary.
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. For agency
approvals and fusing conditions, click on the link below:
http://www.vicorpower.com/technical_library/technical_documentation/quality_and_
certification/safety_approvals/
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.
If the input of the PRM is connected to a centralized DC power system
where the working or float voltage is above SELV, but less than or equal to
75 V, the input and output voltage of the PRM should be classified as a
TNV-2 circuit and spaced 1.3 mm from SELV circuitry or accessible
conductive parts according to the requirements of UL60950-1,
CSA 22.2 60950-1, EN60950-1, and IEC60950-1.
Application Notes
For PRM and VI BRICK application notes on soldering, board layout, and
system design please click on the link below:
http://www.vicorpower.com/technical_library/application_information/
Applications Assistance
Please contact Vicor Applications Engineering for assistance,
1-800-927-9474, or email at [e-mail].
Pre-Regulator Module
PR036A480T012FP
vicorpower.com
Rev. 1.1
Page 11 of 13