Bus Converter Module

BC352A110T030FP

vicorpower.com

Rev. 1.0

Page 7 of 11

+In / -In – DC Voltage Input Ports

The VI BRICK (BCM) input voltage range should not be exceeded. An inter-

nal under / over voltage lockout function prevents operation outside of the

normal operating input range. The BCM turns on within an input voltage

window bounded by the “Input undervoltage turn-on” and “Input

overvoltage turn-off” levels, as specified. The BCM may be protected

against accidental application of a reverse input voltage by the addition of

a rectifier in series with the positive input, or a reverse rectifier in shunt

with the positive input located on the load side of the input fuse.

The connection of the BCM to its power source should be implemented

with minimal distribution inductance. If the interconnect inductance

exceeds 100 nH, the input should be bypassed with a RC damper to retain

low source impedance and stable operation. With an interconnect

inductance of 200 nH, the RC damper may be 2 µF in series with 0.3 Ω. A

single electrolytic or equivalent low-Q capacitor may be used in place of

the series RC bypass.

PC – Primary Control

The Primary Control port is a multifunction node that provides the

following functions:

Enable / Disable – If the PC port is left floating, the BCM output is

enabled. Once this port is pulled lower than 2.4 Vdc with respect

to –In, the output is disabled. This action can be realized by

employing a relay, opto-coupler, or open collector transistor. Refer

to Figures 1-3, 12 and 13 for the typical enable / disable

characteristics. This port should not be toggled at a rate higher

than 1 Hz. The PC port should also not be driven by or pulled up to

an external voltage source.

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

5.0 Vdc. The PC port should never be used to sink current.

Alarm – The BCM contains circuitry that monitors output overload,

input overvoltage or undervoltage, and internal junction temperatures. In

response to an abnormal condition in any of the monitored parameters,

the PC port will toggle. Refer to Figure 13 for PC alarm characteristics.

TM and RSV – Reserved for factory use.

+Out / -Out – DC Voltage Output Ports

Two sets of contacts are provided for the +Out port. They must be

connected in parallel with low interconnect resistance. Similarly, two sets

of contacts are provided for the –Out port. They must be connected in

parallel with low interconnect resistance. Within the specified operating

range, the average output voltage is defined by the Level 1 DC

behavioral model of Figure 16. The current source capability of the BCM is

rated in the specifications section of this document.

The low output impedance of the BCM reduces or eliminates the need for

limited life aluminum electrolytic or tantalum capacitors at the input of POL

converters.

Total load capacitance at the output of the BCM should not exceed the

specified maximum. Owing to the wide bandwidth and low output imped-

ance of the BCM, low frequency bypass capacitance and

significant energy storage may be more densely and efficiently provided by

adding capacitance at the input of the BCM.

PIN / CONTROL FUNCTIONS

Figure 14 — VI BRICK BCM pin configuration (viewed from pin side)