S32K3 GPIO DC electrical specifications

[Chinnan]

When i applied an varying voltage from 0 to 3.3V to controller Pin, The microcontroller taking 1.65 as Input high. Also when i decrease high to low (Ie, 3.3V to 0V) at 1.58V microcontroller took as Input Low.

As per data sheet, For 3.3V microcontroller Input high voltage is 0.7 VDD to VDD and Input low is 0V to 0.3 VDD.

1, Why microcontroller taking 1.65 as Input high? Any software setting required to change or not?

2, What will actually happen in between an voltage comes VIL and VIH?

3, What is the transition voltage of microcontroller?

[Julián_AragónM · Accepted solution]

Hi @Chinnan,

You can find inside the following document, section "Input Characteristics": AN2434: Input/Output Pin Drivers on HCS12 Family MCUs, which still applies to S32K3 family:

When defining VIH or VIL, it is generally set at 70% or 30% of VDD so it is guaranteed that the input reads either LOW or HIGH when input passes those thresholds levels.

Many factors affect the transition voltage level for the MCU, such as temperature. That is why a specific transition voltage is not specified, it is not possible to predict which logic level the MCU will interpret.

Best regards,
Julián

[Chinnan]

Is there any way in the software that any input voltage between 0.3VDD to 0.65VDD on the GPIO pin can be taken as low or high?

[Julián_AragónM]

Hi @Chinnan,

You could set your desired voltage input as a reference by configuring an ADC and using that value as a low or high.

Best regards,
Julián

[Chinnan]

The Microcontroller was S32K322NHT0MPAST  100 Pin HDQFP