PAC1921 datasheet(36/56 Pages) MICROCHIP

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PAC1921 High-Side Current/Power Sensor Evaluation Board User’s Guide

DS50002376A-page 36

 2015 Microchip Technology Inc.

4.3.3

Calculations/File IO Tab

The Calculations/File IO tab, shown in Figure 4-15, displays register data (in decimal

by default). It also shows calculated results which were obtained by applying the data

sheet equations to the register data.

FIGURE 4-15:

Calculations/File IO Tab.

An example of using the equations to calculate power is as follows.

The value of one LSB in the VPOWER Result registers, in watts, can be calculated

according to Equation 4-1.

EQUATION 4-1:

LSB CALCULATION

1LSB

0.1V

 DI_GAIN



----------------------------------------

32V

DV_GAIN

---------------------------



1023 2



--------------------------------------------------------------------------

Where:

1LSB

LSB value in watts for VPOWER Result Registers 1Dh and 1Eh

0.1V

Maximum VSENSE voltage

Value of RSENSE resistor in ohms

DI_GAIN

Digital current gain

32V/DV_GAIN

Maximum voltage

1023

(210 – 1) = 10-bit FSR

Adjustment for 6 unused register bits when read as a 16-bit number

PAC1921 Datasheet(PDF) 36 Page - Microchip Technology