ST7DALIF2 datasheet(114/171 Pages) STMICROELECTRONICS

114 / 171 page

10-bit A/D converter (ADC)

ST7DALIF2

114/171

Figure 52.

ADC block diagram

18.3.2

Input voltage amplifier

The input voltage can be amplified by a factor of 8 by enabling the AMPSEL bit in the

ADCDRL register.

When the amplifier is enabled, the input range is 0V to VDD/8.

For example, if VDD = 5V, then the ADC can convert voltages in the range 0V to 430mV with

an ideal resolution of 0.6mV (equivalent to 13-bit resolution with reference to a VSS to VDD

range).

For more details, refer to the Electrical characteristics section.

Note: The amplifier is switched on by the ADON bit in the ADCCSR register, so no

additional startup time is required when the amplifier is selected by the AMPSEL bit.

18.3.3

Digital A/D conversion result

The conversion is monotonic, meaning that the result never decreases if the analog input

does not and never increases if the analog input does not.

If the input voltage (VAIN) is greater than VDDA (high-level voltage reference) then the

conversion result is FFh in the ADCDRH register and 03h in the ADCDRL register (without

overflow indication).

If the input voltage (VAIN) is lower than VSSA (low-level voltage reference) then the

conversion result in the ADCDRH and ADCDRL registers is 00 00h.

The A/D converter is linear and the digital result of the conversion is stored in the ADCDRH

and ADCDRL registers. The accuracy of the conversion is described in the Electrical

Characteristics Section.

CH2

CH1

EOC SPEED ADON

CH0

ADCCSR

AIN0

AIN1

ANALOG TO DIGITAL

CONVERTER

AINx

ANALOG

MUX

ADCDRH

ADCDRL

AMP

SLOW

AMP

RADC

CADC

HOLD CONTROL

x 1 or

x 8

AMPSEL

bit

SEL

fADC

fCPU

DIV 2

DIV 4

SLOW

bit

CAL

ST7DALIF2 数据表(PDF) 114 Page - STMicroelectronics

ST7DALIF2 数据表(HTML) 114 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 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载