AN2555 - Application note

Modified features

10/33

Note:

sink on this pin on the ST10F276Z5 compared to the ST10F269Zx, it is recommended not

to connect a resistor (for example because of an RC filter), to prevent creating an offset in

the reference.

1.4.3

Software impacts

Self-calibration and ADC initialization routine

An automatic self-calibration adjusts the ADC module to process parameter variations at each reset

event. After reset, the busy flag (read-only) ADBSY is set because the self-calibration is ongoing. The

Table 6.

ADC differences

Parameter

Symbol

Limit values for

ST10F269Zx

Limit values for

ST10F276Z5

Unit

min.

max.

min.

max.

Analog Reference

voltage

4.0

4.5

V

Analog Input Voltage

V

ADC Input capacitance

Port5, Not sampling

Port5, Sampling

Port1, Not Sampling

Port1, sampling

-

-

-

-

10

15

N.A.

N.A.

-

-

-

-

7

10.5

9

12.5

pF

Sample time

48TCL

1536TCL

1µs

120TCL

1600TCL

Conversion time

388TCL

2884TCL

388TCL

2884TCL

Total Unadjusted Error

Port5

Port1 - No overload

Port1 - Overload

TUE

-2.0

-

-

+2.0

-

-

-2.0

-5.0

-7.0

+2.0

+5.0

+7.0

LSB

Internal resistance of

analog source

k

Ω

Analog switch

resistance

Port5

Port1

N.A.

N.A.

-

-

600

1000

Ω

N.A.

N.A.

-

1300

Ω

Reference supply

current

running mode

power-down mode

-

-

500

1

-

-

5000

1

µA

Differential Nonlinearity

DNL

-0.5

+0.5

1

1

LSB

Integral Nonlinearity

INL

-1.5

+1.5

-1.5

1.5

LSB

Offset Error

OFS

-1.0

+1.0

-1.5

1.5

LSB