STPMC1 ST Microelectronics, STPMC1 Datasheet - Page 36

• Manufacturer Part Number: STPMC1
• Description: Programmable poly-phase energy calculator IC
• Manufacturer: ST Microelectronics

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Theory of operation
Figure 12. Phase delay
36/76
The ACR, ACS and ACT registers (bits [7:0], see paragraph 9.17.7) holds the information
needed for this calculation.
Let us indicate t
Equation 1
t
Concatenating ACT[7:0], ACS[7:0], ACR[7:0] bytes, two 12 bits vectors defined as below are
obtained:
ACT[7:0], ACS[7:0], ACR[7:0] = Asr[12, 10:0], Art[12, 10:0]
The delay times are calculated with the following formulas:
Equation 2
Equation 3
From
and t
Example 8: Phase delay calculation
f
RS
XTAL1
+ t
TR
Equation 1
ST
= 4 MHz; MDIV = 0; FR1 = 0
.
t
t
RS
RS
+ t
TR
= T = 1 /
RS
,
Equation 2
, t
t
t
time
ST
ST
time
ST
, t
Asr
Art
TR
, the delays between R, S and T phases. It is:
t
t
t
t
ST
and
RS
TR
TR
Doc ID 15728 Rev 1
t
Equation 3
t
TR
ST
⎛
⎜
⎝
f
⎛
⎜
⎝
MCLK
Asr
Art
10
10
it is possible to retrieve phase delays t
= 8 MHz
0 :
0 :
2
2
11
11
Art
Asr
12
12
1
1
⎞
⎟
⎠
⎞
⎟
⎠
f
MCLK
f
MCLK
8
8
STPMC1
RS
, t
ST