AT89C51AC3-RDTIM datasheet(105/140 Pages) ATMEL

105 / 140 page

105

AT89C51AC3

4383D–8051–02/08

Analog-to-Digital

Converter (ADC)

This section describes the on-chip 10 bit analog-to-digital converter of the

AT89C51AC3. Eight ADC channels are available for sampling of the external sources

AN0 to AN7. An analog multiplexer allows the single ADC converter to select one from

the 8 ADC channels as ADC input voltage (ADCIN). ADCIN is converted by the 10-bit

cascaded potentiometric ADC.

Two kinds of conversion are available:

- Standard conversion (8 bits).

- Precision conversion (10 bits).

For the precision conversion, set bit PSIDLE in ADCON register and start conversion.

The device is in a pseudo-idle mode, the CPU does not run but the peripherals are

always running. This mode allows digital noise to be as low as possible, to ensure high

precision conversion.

For this mode it is necessary to work with end of conversion interrupt, which is the only

way to wake the device up.

If another interrupt occurs during the precision conversion, it will be treated only after

this conversion is ended.

Features

•

8 channels with multiplexed inputs

•

10-bit cascaded potentiometric ADC

•

Conversion time 16 micro-seconds (typ.)

•

Zero Error (offset) ± 2 LSB max

•

Positive External Reference Voltage Range (VREF) 2.4 to 3.0Volt (typ.)

•

ADCIN Range 0 to 3Volt

•

Integral non-linearity typical 1 LSB, max. 2 LSB

•

Differential non-linearity typical 0.5 LSB, max. 1 LSB

•

Conversion Complete Flag or Conversion Complete Interrupt

•

Selectable ADC Clock

ADC Port1 I/O Functions

Port 1 pins are general I/O that are shared with the ADC channels. The channel select

bit in ADCF register define which ADC channel/port1 pin will be used as ADCIN. The

remaining ADC channels/port1 pins can be used as general-purpose I/O or as the alter-

nate function that is available.

A conversion launched on a channel which are not selected on ADCF register will not

have any effect.

AT89C51AC3-RDTIM 数据表(PDF) 105 Page - ATMEL Corporation

AT89C51AC3-RDTIM 数据表(HTML) 105 Page - ATMEL Corporation

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