adm1075-2aruz-rl7 Analog Devices, Inc., adm1075-2aruz-rl7 Datasheet - Page 33

• Manufacturer Part Number: adm1075-2aruz-rl7
• Description: −48 V Hot Swap Controller And Digital Power Monitor With Pmbus Interface
• Manufacturer: Analog Devices, Inc.

Data Sheet
The settings that can be configured are as follows:
•
•
•
•
Modifying the power monitor settings while the power monitor
is sampling is not recommended because it may cause spurious
data or warnings to be generated.
PMON_CONTROL Command
Power monitor sampling can be initiated via software or via
hardware, as follows:
•
•
READ_VIN, READ_VAUX, and READ_IOUT Commands
The
across the sense resistor to provide a current measurement. The
input voltage from the ADC_V pin is always measured, and the
user can choose whether or not to measure the output voltage
present on the ADC_AUX pin as well.
READ_PIN, READ_PIN_EXT, READ_EIN, and
READ_EIN_EXT Commands
The VIN input voltage (12-bit) and IOUT current (12-bit)
measurement values are multiplied by the
input power value. This is done using fixed point arithmetic and
produces a 24-bit value. It is assumed that the numbers are of
the 12.0 format, meaning there is no fractional part. It should
be noted that only positive IOUT values are used to avoid
returning a negative power.
This 24-bit value can be read from the
READ_PIN_EXT command, where the most significant bit
(MSB) is always a zero because PIN_EXT is a twos complement
binary value that is always positive.
The 16 most significant bits of the 24-bit value are used as the
value for input power (PIN). The MSB of the 16-bit PIN word is
always zero because PIN is a twos complement binary value that
is always positive.
Each time a power calculation is performed, the 24-bit power
value is added to a 24-bit energy accumulator register. This is a
twos complement representation as well; therefore, the MSB is
always zero. Each time this energy accumulator register rolls
over from 0x7FFFFF to 0x000000, a 16-bit rollover counter is
incremented. The rollover counter is straight binary, with a
maximum value of 0xFFFF before it rolls over.
There is also a 24-bit straight binary power sample counter that
is incremented by one each time a power value is calculated and
added to the energy accumulator.
ADM1075
Single-shot or continuous sampling
Enable VAUX sampling
Current input range
Current and voltage sample averaging
PMON_CONTROL command. This command can be
used with single-shot or continuous mode.
GPO1/ ALERT1 /CONV pin. If this pin is configured for
convert mode, an external hardware signal can be used to
take this pin high, triggering the single-shot sampling of
one or more parts together.
power monitor measures the voltage developed
ADM1075
ADM1075
using the
to give the
Rev. 0 | Page 33 of 52
These registers can be read back using one of two commands,
depending on the level of accuracy required for the energy
accumulator and the desire to limit the frequency of reads from
the ADM1075.
A bus host can read these values, and, using some difference
calculations, determine the amount of energy consumed since
the last read and the number of samples in that time. The bus
host, using an external real-time clock, can then determine the
power used in the last time period.
To avoid the loss of data, the bus host must read at a rate that
ensures the rollover counter does not wrap around more than
once and, if it does wrap around, that the next rollover value is
less than the previous one.
The READ_EIN command returns the top 16 bits of the energy
accumulator, the lower eight bits of the rollover counter, and the
full 24 bits of the sample counter.
The READ_EIN_EXT command returns the full 24 bits of the
energy accumulator, the full 16 bits of the rollover counter, and
the full 24 bits of the sample counter. The use of the longer
rollover counter means that the time interval between reads of
the part to ensure that no data is lost can be increased from
seconds to minutes.
PEAK_IOUT, PEAK_VIN, PEAK_VAUX, and PEAK_PIN
Commands
In addition to the standard PMBus commands for reading
voltage and current, the
can report the maximum peak voltage, current, or power value
since the peak value was last cleared.
The peak values are updated only after the power monitor has
sampled and averaged the current and voltage measurements.
Individual peak values are cleared by writing a 0 value with the
corresponding commands.
WARNING LIMIT SETUP COMMANDS
The
different warning conditions simultaneously and report any
current or voltage values that exceed the user-defined
thresholds using the status commands.
All comparisons performed by the power monitor require the
measured voltage or current value to be strictly greater or less
than the threshold value.
At power-up, all threshold limits are set to either minimum
scale (for undervoltage or undercurrent conditions) or to
maximum scale (for overvoltage, overcurrent or overpower
conditions). This effectively disables the generation of any
status warnings by default; warning bits are not set in the status
registers until the user explicitly sets the threshold values.
VIN_OV_WARN_LIMIT and VIN_UV_WARN_LIMIT
Commands
The VIN_OV_WARN_LIMIT and VIN_UV_WARN_LIMIT
commands are used to set the OV and UV thresholds on the
input voltage, as measured at the ADC_V pin.
ADM1075
power monitor can monitor a number of
ADM1075
provides commands that
ADM1075