Datasheet

STPMC1 Theory of operation
Doc ID 15728 Rev 7 47/77
0.4 PRD:
● period: 12-bit line period measurement (see paragraph 9.6 ). By default it is calculated
from R-phase signal, if it is missing from S-phase then from T-phase. The value of the
period can be calculated from the decimal value of period as:
Equation 10
● DC uN: 16-bit DC component of voltage channel of NDSP. It may be DAN-V or DAH
according to the value of ENH
bit. For example it is DC offset in sigma delta uN if
ENH
=0, or DC value of magnetic field if ENH is set and a magnetic sensor is connected
via STPMSx on DAH input.
9.17.2 Group 1 data records
1.1 DMR:
● uR MOM: 12-bit momentary value of R phase voltage
● iR MOM: 16-bit momentary value of R phase current
1.2 DMS:
● uS MOM: 12-bit momentary value of S phase voltage
● iS MOM: 16-bit momentary value of S phase current
1.3 DMT:
● uT MOM: 12-bit momentary value of T phase voltage
● iT MOM: 16-bit momentary value of T phase current
1.4 DMN:
● sI RMS: 12-bit RMS value of the sum of all the instantaneous currents (i
R
+ i
S
+ i
T
+ i
N
)
divided by four:
MCLK
6
f
2period
T
⋅
=
Figure 15. Group 1 data records
DMN
DMR
DMS
DMT
parity iR MOMuR MOM
parity iS MOMuS MOM
parity iT MOMuT MOM
parity iN MOMsI RMS
12 bit4 bit 16 bit
DMN
DMR
DMS
DMT
parity iR MOMuR MOMparity iR MOMuR MOM
parity iS MOMuS MOMparity iS MOMuS MOM
parity iT MOMuT MOMparity iT MOMuT MOM
parity iN MOMsI RMSparity iN MOMsI RMS
12 bit12 bit4 bit4 bit4 bit 16 bit16 bit
DMN
DMR
DMS
DMT
parity iR MOMuR MOM
parity iS MOMuS MOM
parity iT MOMuT MOM
parity iN MOMsI RMS
12 bit4 bit 16 bit
DMN
DMR
DMS
DMT
parity iR MOMuR MOMparity iR MOMuR MOM
parity iS MOMuS MOMparity iS MOMuS MOM
parity iT MOMuT MOMparity iT MOMuT MOM
parity iN MOMsI RMSparity iN MOMsI RMS
12 bit12 bit4 bit4 bit4 bit 16 bit16 bit