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BMR46 series PoL Regulators
BMR46 series PoL Regulators
Input 4.5-14 V, Output up to 50 A / 165 W
Input 4.5-14 V, Output up to 50 A / 165 W
PMBus interface
This product provides a PMBus digital interface that enables
the user to configure many aspects of the device operation as
well as to monitor the input and output voltages, output current
and device temperature. The product can be used with any
standard two-wire I
C or SMBus host device. In addition, the
2
product is compatible with PMBus version 1.3 and includes an
SALERT line to help mitigate bandwidth limitations related to
continuous fault monitoring. The product supports 100 kHz
and 400kHz bus clock frequency only. The PMBus signals,
SCL, SDA and SALERT require passive pull-up resistors as
stated in the SMBus Specification. Pull-up resistors are
required to guarantee the rise time as follows:
Eq. 6.
R
C
1
p
p
where R
is the pull-up resistor value and C
p
loading, the maximum allowed bus load is 400 pF. The pull-up
resistor should be tied to an external supply voltage in range
from 3 to 5.5 V, which should be present prior to or during
power-up. If the proper power supply is not available, voltage
dividers may be applied. Note that in this case, the resistance
in the equation above corresponds to parallel connection of
the resistors forming the voltage divider.
See application note AN304 for details on interfacing the
product with a microcontroller.
Monitoring via PMBus
It is possible to monitor a wide variety of parameters through
the PMBus interface. Fault conditions can be monitored using
the SALERT pin, which will be asserted when any number of
pre-configured fault or warning conditions occurs. It is also
possible to continuously monitor one or more of the power
conversion parameters including but not limited to the
following:
•
Input voltage (READ_VIN)
Output voltage (READ_VOUT)
•
Output current (READ_IOUT)
•
•
Internal junction temperature (READ_TEMPERATURE_1)
•
Switching frequency (READ_FREQUENCY)
Duty cycle (READ_DUTY_CYCLE)
•
In the default configuration monitoring is enabled also when
the output voltage is disabled. This can be changed in order to
reduce standby power consumption.
s
is the bus
p
Technical Specification
Technical Specification
1/28701-BMR 464 Rev.B
1/28701-BMR 464 Rev.B
© Flex
© Flex
Snap shot parameter capture
This product offers a special feature that enables the user to
capture parametric data during normal operation or following a
fault. The following parameters are stored:
Input voltage
•
•
Output voltage
•
Output current
Internal junction temperature
•
Switching frequency
•
•
Duty cycle
•
Status registers
The Snapshot feature enables the user to read the parameters
via the PMBus interface during normal operation, although it
should be noted that reading the 22 bytes will occupy the bus
for some time. The Snapshot enables the user to store the
snapshot parameters to Flash memory in response to a
pending fault as well as to read the stored data from Flash
memory after a fault has occurred. Automatic store to Flash
memory following a fault is triggered when any fault threshold
level is exceeded, provided that the specific fault response is
to shut down. Writing to Flash memory is not allowed if the
device is configured to restart following the specific fault
condition. It should also be noted that the device supply
voltage must be maintained during the time the device is
writing data to Flash memory; a process that requires between
700-1400 μs depending on whether the data is set up for a
block write. Undesirable results may be observed if the input
voltage of the product drops below 3.0 V during this process.
66
July 2019
July 2019
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