Voltage Transformation Module

MT036 SERIES

vicorpower.com

Rev. 1.0

Page 7 of 11

+In / -In DC Voltage Ports

The VTM input should not exceed the maximum specified. Be aware of this

limit in applications where the VTM is being driven above its nominal out-

put voltage. If less than 26 Vdc is present at the +In and -In ports, a contin-

uous VC voltage must be applied for the VTM to process power. Otherwise

VC voltage need only be applied for 10 ms after the voltage at the +In and

-In ports has reached or exceeded 26 Vdc. If the input voltage exceeds the

overvoltage turn-off, the VTM will shutdown. The VTM does not have

internal input reverse polarity protection. Adding a properly sized diode in

series with the positive input or a fused reverse-shunt diode will provide

reverse polarity protection.

TM – For Factory Use Only

VC – VTM Control

upstream PRM, synchronizing the output rise of the VTM with the output

rise of the PRM. Additionally, the VC port provides feedback to the PRM to

compensate for the VTM output resistance. In typical applications using

VTMs powered from PRMs, the PRM’s VC port should be connected to the

VTM VC port.

In applications where a VTM is being used without a PRM, 14 V must be

supplied to the VC port for as long as the input voltage is below 26 V and

for 10 ms after the input voltage has reached or exceeded 26 V. The VTM is

not designed for extended operation below 26 V. The VC port should only be

PC – Primary Control

The Primary Control (PC) port is a multifunction port for controlling the

VTM as follows:

Disable – If PC is left floating, the VTM output is enabled. To

disable the output, the PC port must be pulled lower than 2.4 V,

referenced to -In. Optocouplers, open collector transistors or relays

can be used to control the PC port. Once disabled, 14 V must be

re-applied to the VC port to restart the VTM.

Primary Auxiliary Supply – The PC port can source up to 2.4 mA

at 5 Vdc.

+Out / -Out DC Voltage Output Ports

The output and output return are through two sets of contact locations.

The respective +Out and –Out groups must be connected in parallel with

as low an interconnect resistance as possible.

To take full advantage of the VTM, the user should note the low output

impedance of the device. The low output impedance provides fast tran-

sient response without the need for bulk POL capacitance. Limited-life

electrolytic capacitors required with conventional converters can be

reduced or even eliminated, saving cost and valuable board real estate.

PIN / CONTROL FUNCTIONS

Figure 9 — VI BRICK VTM pin configuration (viewed from pin side)