12 bit mode ADC performance

[lechlachowicz]

I have been comparing the KL15 to the MSP430F5437 analog input
specifications.

Freescalue document Table 20 - 16 bit ADC specifications K15 data sheet KL15P80M48SF0.pdf

TI document - 12 bit ADC Linearity Parameters data sheet MSP430F5436.pdf

Here are my questions:

1.     For the KL15 what is the LSB equal to (1/4906) or (1/65536) when the “conditions” for item INL and DNL is “12 bit
        mode”? (I assume when the conditions are = 12 bit mode then the LSB = 1/4096).

2.      The KL15 INL max./min. values are -2.7 to +1.9 LSB and the DNL is -1.1 to +1.9 LSB for “12
          bit mode” with VREFH = VCC and VREFL = GND.  I can only assume that the
          Min./Max. values are at room temperature, not over the temperature range.
          What are the INL and DNL values for VREFH less than VCC.

3.     The MSP430 INL is +/-1.7 LSB and the DNL +/-1 LSB for a [Veref+] – [Vref-/Veref-]min between 1.6V
          and VACC.  The values are specified over the full temperature operating range.

4.     What is the KL15 worst case offset error?  It is not specified but a TUE is specified for the part.

Lech

[apanecatl · Accepted solution]

Hi Lechlachowics:

1. KL15 LSB when the ADC is working in 12-bit mode equals 1/4096
2. KL15 INL and DNL values are maintained across the full temperature operating range though the datasheet depicted values are tested at 25 ºC and VREFH=VCC
3. Although the offset error is not characterized, the worst case error is quantified as TUE= +/-5.4 LSB for 12-bit mode

[lechlachowicz]

Thank you