Datasheet

STPM10 Theory of operation
Doc ID 17728 Rev 4 17/53
The gain register is included in the device configuration register with the address name
PST. The table below shows the gain configuration according to the register values:
Note: If the device is used in configuration PST = 1, TMP = 1 (primary channel with CT, secondary
channel with Shunt), the shunt Ks must always be equal to one fourth of the current
transformer Ks.
Both the voltage and current channels implement an active offset correction architecture
which provides the benefit of avoiding any offset compensation.The analog voltage and
current signals are processed by the Σ Δ analog-to-digital converters, which feed the hard-
wired DSP. The DSP implements an automatic digital offset cancellation that makes it
possible to avoid any manual offset calibration on the analog inputs.
Table 6. Gain of voltage and current channels
Voltage channels Current channels
Gain Max input voltage (V) Gain Max input voltage (V)
4 ±0.30
8X ±0.15
32X ±0.035
Table 7. Configuration of current sensors
Primary Secondary
Configuration
Bits
Configuration
Bits
Gain Sensor Gain Sensor PST TMP
8 CT Disabled Disabled 0 0
32 Shunt Disabled Disabled 1 0
8
CT
8CT0 1
8 32 Shunt 1 1