Datasheet

LM5066
www.ti.com SNVS655G –JUNE 2011–REVISED FEBRUARY 2013
READING POWER
The power calculation of the LM5066 is a relative power calculation meaning that full scale of the power register
corresponds to simultaneous full scale values in the current register and voltage register such that the power
register has the following relationship based on decimal equivalents of the register contents:
(48)
For this reason power coefficients will also vary depending on the shunt value and must be calculated for each
application. The power LSB will vary depending on shunt value according to 828 µW/Rsense for the 26mV range
or 1.65 mW/Rsense for the 50mV range.
Step Example
1. Determine full scale power from known full scale of input current Example: 8.6A application with 3 mΩ shunt.
and input voltage: P
IN_MAX
= (89.3V) x (76 mV / 3 mΩ) = 2262W
P
IN_MAX
= V
IN_MAX
x I
IN_MAX
2. Determine m':
(50)
(49)
3. Optional: Determine exponent R necessary to set m' to integer Select R to provide 16 bit accuracy for the integer value of m :
value m with desired accuracy:
(52)
(51)
R = -4
4. Final values m = 18103
R = -4
b = 0
Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 51
Product Folder Links: LM5066