Can AD conversion detect negative voltage?(I use S12ZVL family)

[Jen1]

DJM: Result Register Data Justification — Conversion result data format is always unsigned. This bit controls justification of conversion result data in the conversion result list.

Q: I want to detect the negative voltage in the circuit, but according to the data manual, the conversion result is always unsigned. How can I detect the negative voltage with sign?  

[Jen1]

Thank you very much for your answer.

I have some other question:  Can I measure more than 9 volts or 16v?

[danielmartynek]

Yes, it is, using HVI (High Voltage Inputs).

Please refer to the S12ZVL RM.

2.4.5 High-Voltage Input

J.1 High-Voltage Inputs (HVI) Electrical Characteristics.

BR, Daniel

[danielmartynek]

Hi @Jen1,

The ADC can't measure negative voltage.

The input voltage (V_IN) must be within the <V_RL; V_RH> range.

If negative voltage (V_IN < VSSA) is applied to a pin, the voltage is clamped to VSS.

Please refer to the S12ZVL RM,

C.1.1.4 Current Injection.

A.1.2 Current Injection

Table A-10. 5V I/O Characteristics (Junction Temperature From –40C To +175C)

Regards,

Daniel