ISL28025 Datasheet, PDF (28/47 Pages) Intersil Corporation – Precision Digital Power Monitor with Real Time Alerts

ISL28025
0XD7 CONFIGURE PEAK DETECTOR (R/W)
The Configure Peak Detector register is a read/writable byte
register that toggles the minimum and maximum current
tracking feature. A Peak Detect Enable bit setting of 1 enables
the current peak detect feature of the DPM. The feature is
discussed in more detail in the “0xD8 Read Peak Min IOUT (R)”
section.
TABLE 20. 0xD7 CONFIGURE PEAK DETECTOR REGISTER DEFINITION
BIT NUMBER
D[7:1]
D[0]
Bit Name
N/A
Peak Detect En
Default
0000 000
0
Value
Measurement Registers
0XD6 READ V_SHUNT OUT (R)
The Read V_SHUNT Out register is a readable word register that
stores the signed measured digital value of the primary V_SHUNT
input of the DPM. Using Equation 2 to calculate the integer value
of the register, Equation 6 calculates the floating point measured
value for the primary V_SHUNT channel.
V_SHUNT = Register_value  V_{SHUNTLSB}
(EQ. 6)
V_SHUNT(LSB) is the numerical weight of each level for the V_SHUNT
channel, which equals 2.5µV.
0X8B READ V_OUT (R)
The Read V_OUT register is a readable word register that stores the
unsigned measured digital value of the primary V_BUS input of the
DPM. Using Equation 1 to calculate the integer value of the
register, Equation 7 calculates the floating point measured value
for the primary V_BUS channel.
V_BUS = Register_value  V_{BUSLSB}
(EQ. 7)
V_BUS(LSB) is the numerical weight of each level for the V_BUS
channel. The V_BUS(LSB) equals 1mV for the 60V version of the
DPM and 250µV for the 12V version of the DPM.
0X8C READ I_OUT (R)
The Read I_OUT register is a readable word register that stores the
signed measured digital value of the current passing through the
primary channel’s shunt. The register uses the measured value
from V_SHUNT and the IOUT_CAL_GAIN register. Equation 8 yields
the current for the primary channel.
Current = Register_value  Current_LSB
(EQ. 8)
The Register_value is calculated using Equation 2. The Current_LSB
is calculated using Equation 4.
0XD8 READ PEAK MIN I_OUT (R)
0XD9 READ PEAK MAX I_OUT (R)
FIGURE 66. THE ISL28025 TRACKS MINIMUM AND MAXIMUM
AVERAGE CURRENT READINGS
The Read Peak Min/Max I_OUT registers are readable word
registers that store the minimum and maximum current value of
an averaging cycle for the current passing through the primary
shunt.
The min/max current tracking is enabled by setting the Peak
Detect Enable bit in the CONFIG_PEAK_DET (0xD7) register. The
current peak detect feature only works for the current register.
At the conclusion of each primary channel current, the DPM will
record and store the minimum and maximum values of the
current measured. The feature operates for both the trigger and
continuous modes. Disabling the Peak Detector Enable bit will
turn off the feature as well as clear the Read Peak Min/Max I_OUT
registers.
0X96 READ P_OUT (R)
The Read P_OUT register is a signed readable word register that
reports the digital value of the power from the primary channel.
The register uses the values from READ_IOUT and
READ_VSHUNT_OUT registers to calculate the power.
The units for the power register are in watts. The power can be
calculated using Equation 9.
Power = Register_value  Power_LSB  40000
(EQ. 9)
The Register_value is calculated using Equation 2 on page 24. The
Power_LSB can be calculated from Equation 10.
Power_LSB = Current_LSB  V_{BUSLSB}
(EQ. 10)
The V_BUS(LSB) equals 1mV for the 60V version of the DPM and
250µV for the 12V version of the DPM. The Current_LSB is the
value yielded from Equation 4.
0XE1 READ VOUT AUX (R)
The Read Vout Aux register is a readable word register that stores
the unsigned measured digital value of the auxiliary V_BUS input
of the DPM. Using Equation 1 on page 24 to calculate the integer
value of the register, Equation 11 calculates the floating point
measured value for the auxiliary V_BUS channel.
V_BUS = Register_value  V_{BUSLSB}
(EQ. 11)
V_BUS(LSB) is the numerical weight of each level for the auxiliary
V_BUS channel. The auxiliary V_BUS(LSB) equals 100µV. The voltage
range for the auxiliary V_BUS is 0 to VCC.
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FN8388.3
June 17, 2015