4x analog universal inputs
2x NTC temperature measurement input
1x current measuring input (high side)
1x voltage measurement input
the measuring range is 0 to 3.3 volts and can be expanded with an optional resistor.
For this purpose, the input resistor R64 (1k) forms a divider with the optional R68.
For a measuring range of 0 - 5 volts: R68 is equipped with 1.8kOhm (results in a measuring range of 0 - 5.13V)
these are provided as standard for an NTC type: B57703M103G. When using other NTCs, R71 or R72 may have to be changed
it is a high-side detector, i.e. the current is measured in the positive line. A shunt resistor (e.g. 1 milliohm) is inserted into the positive line (e.g. between power supply unit and consumer). The voltage drop across the shunt is fed to the detector via ST9.
The measured voltage corresponds to the voltage drop across the shunt x 20.
Shunt: 1mOhm Electricity: 20 amps
a voltage of 1mOhm x 20A = 20mV drops at the shunt. The voltage to be measured of 20mV x 20 = 0.4V is then present at the detector output.
The input for voltage measurement is wired internally. The voltage at the shunt to ground is measured, which corresponds to the supply voltage of the consumer.
The MAX11615EEET is used as the ADC. This is an 8-channel ADC with 12 bit resolution.