STEVAL-IPE012V1 STMicroelectronics, STEVAL-IPE012V1 Datasheet - Page 42

• Manufacturer Part Number: STEVAL-IPE012V1
• Description: EVAL BOARD ENERGY METER
• Manufacturer: STMicroelectronics
• Series: -r

Specifications of STEVAL-IPE012V1

• Design Resources: STEVAL-IPE012V1 Schematic STEVAL-IPE012V1 BOM
• Main Purpose: Power Management, Energy/Power Meter
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: STPM10BTR, STM8L152
• Primary Attributes: Single Phase with 1 Current Transformer & Shunt
• Secondary Attributes: Tamper Detection
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11462

Theory of operation
Table 14.
42/51
Internal reference voltage
Internal calculation frequency
Amplification of voltage ADC
Amplification of current ADC
Gain of differentiator
Gain of integrator
Gain of decimation filter
RMS voltage record length
RMS current record length
Constant
Device constants
As shown in
introduce a certain error. Voltage ADC amplification A
according to the sensors used.
The calibration algorithm first calculates the voltage divider ratio and, as a final result, the
correction parameters, called K
measures compensate the small tolerances of the analog components that affect energy
calculation.
Since K
configuration bytes CHV and CHP or CHS (respectively, the voltage channel, primary
current channel and secondary current channel calibration bytes), at the end of calibration,
CHV and CHP or CHS (according to the current channel under calibration, primary or
secondary, respectively) the bits' values are obtained.
In the following procedure CHV, CHP and CHS are indicated as C
Through hard-wired formulas, K
steps, according to the value of C
To obtain the greatest correction dynamic, initially calibrators are set in the middle of the
range, thus obtaining a calibration range of 12.5% per voltage or current channel:
Calibrator value
In this way, it is possible to tune K
= 0 generates a correction factor of -12.5% (K
correction factor of +12.5% (K
Based on the above, the following formulas relating to K
v
and K
Table 14
Parameter
i
calibration parameters are the decimal representation of the corresponding
, only analog parameters are the object of calibration because they
v
K
Doc ID 17728 Rev 3
v
v
= 1), and so on.
v,i
and K
and K
v
v
= (C
C
and C
and K
G
G
V
G
D
A
B
f
A
B
v,i
BG
DIF
INT
UD
M
DF
V
V
I
I
K
v,i
i
i
= 1024 * K
C
, which applied to STPM10 voltage and current
tune measured values varying from 0.75 to 1, in 256
v
i
/ 128) * 0.125 + 0.75
i
i
= K
= C
to obtain a precise measurement: for example C
(from 0 to 255).
i
v
= 0.875
v
= 128
= 0.75) and C
v,i
- 768
v
8, 16, 24, 32
is constant, while A
v
0.6135
,i and C
1.23 V
2
Value
0.815
1.004
23
2
2
2
4
11
16
17
Hz
v
= 255 determines a
v
,i are obtained:
v
and C
i
.
i
is chosen
Tolerance
± 50 ppm
± 2%
± 1%
± 2%
STPM10
v