STR730FZ1T7 datasheet(44/52 Pages) STMICROELECTRONICS

44 / 52 page

Electrical parameters

STR73xFxx

44/52

ADC accuracy vs. negative injection current: Injecting negative current on any of the standard (non-robust)

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. The effect of negative injection current on robust

pins is specified in Section 4.3.5.

Any positive injection current within the limits specified for IINJ(PIN) and ΣIINJ(PIN) in Section 4.3.5 does not

affect the ADC accuracy.

Calibration is needed once after each power-up.

Figure 21. ADC accuracy characteristics

Figure 22. Typical application with ADC

Table 27.

ADC accuracy with fMCLK = 20 MHz, fADC=10 MHz, RAIN < 10 kΩ RAIN,

VDDA=5 V. This assumes that the ADC is calibrated

Symbol

Parameter

Conditions

Typ

Max

Unit

|ET|

Total unadjusted error 1)

1.0

2.0

LSB

|EO|

Offset error 1)

0.15

1.0

|EG|

Gain error 1)

0.97

1.1

|ED|

Differential linearity error1)

0.7

1.0

|EL|

Integral linearity error 1)

0.76

1.5

1LSBIDEAL

1LSB

IDEAL

DDA

SSA

–

1024

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

(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.

1023

1022

1021

345

1021 1022 1023 1024

(1)

(2)

(3)

VDDA

VSSA

AINx

STR73X

VDD

±1

μA

0.6V

CADC

3.5pF

VAIN

RAIN

10-Bit A/D

conversion

2.3k

Ω(max)

CAIN

STR730FZ1T7 数据表(PDF) 44 Page - STMicroelectronics

STR730FZ1T7 数据表(HTML) 44 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

数据表下载