AN1313 - APPLICATION NOTE

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2.4 - A/D Converter

The A/D Converter of the ST10F269 is based upon a Resistor-Capacitor circuitry while the ST10F168

one is based upon fully switched capacitors. The ST10F269 does not have the self-calibrated feature, but

the guaranteed Total Unadjusted Error is ± 2 LSB.

2.4.1 - Hardware Impacts

The table below lists the differences in the DC characteristics of the two devices.

2.4.2 - Software Impacts

None.

Table 2 : ADC differences

Parameter

Symbol

Limit values for ST10F168

Limit values for ST10F269

Unit

Minimum

Maximum

Minimum

Maximum

Analog Reference voltage

4.0

4.0

V

Analog Input Voltage

V

ADC Input capacitance

Not sampling

Sampling

-

-

33

33

-

-

10

15

pF

pF

Sample time

Conversion time

-

Total Unadjusted Error

TUE

-2.0

+2.0

-2.0

+2.0

LSB

Internal resistance of analog

source

k

Ω

Reference supply current

running mode

power-down mode

-

-

500

1

µA

µA

Differential Nonlinearity

DNL

-0.5

+0.5

LSB

Integral Nonlinearity

INL

-1.5

+1.5

LSB

Offset Error

OFS

-1.0

+1.0

LSB