bcm352f125t300a00 Vicor Corporation, bcm352f125t300a00 Datasheet - Page 13

• Manufacturer Part Number: bcm352f125t300a00
• Description: Bcmtm Bus Converter
• Manufacturer: Vicor Corporation

5.0 USING THE CONTROL SIGNALS TM AND PC
The PC control pin can be used to accomplish the following
functions:
• Delayed start: At start-up, PC pin will source a constant
• Synchronized start up: In a parallel module array, PC pins
• Auxiliary voltage source: Once enabled in regular
• Output Disable: PC pin can be actively pulled down in order
• Fault detection flag: The PC 5 V voltage source is internally
The temperature monitor (TM) pin provides a voltage propor-
tional to the absolute temperature of the converter control IC.
It can be used to accomplish the following functions:
• Monitor the control IC temperature: The temperature in
• Fault detection flag: The TM voltage source is internally
v i c o r p o w e r. c o m
100 uA current to the internal RC network. Adding an
external capacitor will allow further delay in reaching the
2.5 V threshold for module start.
shall be connected in order to ensure synchronous start of all
the units. While every controller has a calibrated 2.5 V
reference on PC comparator, many factors might cause
different timing in turning on the 100 uA current source on
each module, i.e.:
– Different V
– Statistical component value distribution
By connecting all PC pins, the charging transient will be
shared and all the modules will be enabled synchronously.
operational conditions (no fault), each BCM PC provides a
regulated 5 V, 2 mA voltage source.
to disable module operations. Pull down impedance shall be
lower than 400 Ω and toggle rate lower than 1 Hz.
turned off as soon as a fault is detected. After a minimum
disable time, the module tries to re-start, and PC voltage is
re-enabled. For system monitoring purposes (microcontroller
interface) faults are detected on falling edges of PC signal.
It is important to notice that PC doesn’t have current sink
capability (only 150 kΩ typical pull down is present),
therefore, in an array, PC line will not be capable of disabling
all the modules if a fault occurs on one of them.
Kelvin is equal to the voltage on the TM pin scaled
by x100. (i.e. 3.0 V = 300 K = 27ºC). It is important to
remember that V
temperature distribution greatly vary for each part number as
well with input/output conditions, thermal management and
environmental conditions. Therefore, TM cannot be used to
thermally protect the system.
turned off as soon as a fault is detected. After a minimum
disable time, the module tries to re-start, and TM voltage is
re-enabled.
IN
slew rate
•
I chips are multi-chip modules, whose
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
PRELIMINARY DATASHEET
BCM352F125T300A00 - BCM352T125T300A00
6.0 FUSE SELECTION
V
in configuring power systems. Input line fusing of V
recommended at system level, in order to provide thermal
protection in case of catastrophic failure.
The fuse shall be selected by closely matching system
requirements with the following characteristics:
• Current rating (usually greater than maximum BCM current)
• Maximum voltage rating (usually greater than the maximum
• Ambient temperature
• Nominal melting I
• Recommended fuse: ≤2.5 A Bussmann PC-Tron or
•
possible input voltage)
SOC type 36CFA.
I Chips are not internally fused in order to provide flexibility
2
t
•
I Chips is
Page 13 of 17
12/2010
Rev. 1.6