STM8S105C4 datasheet(87/121 Pages) STMICROELECTRONICS

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DocID14771 Rev 15

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STM8S105x4/6

Electrical characteristics

Figure 45. ADC accuracy characteristics

1. Example of an actual transfer curve

2. The ideal transfer curve

3. End point correlation line



ET = Total unadjusted error: maximum deviation between the actual and the ideal transfer curves.

EO = Offset error: deviation between the first actual transition and the first ideal one.

EG = Gain error: deviation between the last ideal transition and the last actual one.

ED = Differential linearity error: maximum deviation between actual steps and the ideal one.

EL = Integral linearity error: maximum deviation between any actual transition and the end point correlation

line.

Figure 46. Typical application with ADC

1. Legend: RAIN = external resistance, CAIN = capacitors, Csamp = internal sample and hold capacitor.

2. ADC accuracy vs. negative injection current: Injecting negative current on any of the analog input pins

should be avoided as this significantly reduces the accuracy of the conversion being performed on another

analog input. It is recommended to add a Schottky diode (pin to ground) to standard analog pins which may

potentially inject negative current. Any positive injection current within the limits specified for IINJ(PIN) and

IINJ(PIN) in Section 10.3.6 does not affect the ADC accuracy.

1LSBIDEAL

VDDA VSSA

–

1024

-----------------------------------------

1023

1022

1021

234

567

1021102210231024

(1)

(2)

(3)

VDDA

VSSA

STM8S105C4 Datasheet(PDF) 87 Page - STMicroelectronics