Hi.
In the Voltage Monitoring circuit using LM96194, the value read from registers corresponding to AD-IN1 to AD_IN5 is as expected (i.e. close to 0xC0). The inputs AD_IN 1 to AD_IN3 are scaled by an external resistor divider to get a nominal voltage of 0.91V. This value (0xC0) when multiplied by a scaling factor (Input voltage/192) gives an actual input voltage applied.
- For AD_IN6 and AD_IN7 the inputs (2.5V and 5V) are given through resistor dividers such that the divided voltage at the input pin is 0.984V.
- The value read from registers corresponding to AD-IN6 to AD_IN7 is 0xBA and 0xB5 respectively instead of 0xC0 (nominal) value.
- These values (0xBA and 0xB5) when multiplied by a scaling factors (13.02mV and 26.04mV) does not give the actual input voltages applied.
As I understand the AD_IN6 & 7 pins have internal divider resistors (sum is 140K). Can u please let us know what care should be taken in accounting for the error due to internal resistor dividers while calculating the scaling factors.
Regards,
Sachin.