ATmega64A datasheet(233/392 Pages) ATMEL

233 / 392 page

233

8160C–AVR–07/09

ATmega64A

23. Analog to Digital Converter

23.1

Features

• 10-bit Resolution

• 0.75 LSB Integral Non-linearity

• ±1.5 LSB Absolute Accuracy

• 13 - 260 µs Conversion Time

• Up to 15 kSPS at Maximum Resolution

• Eight Multiplexed Single Ended Input Channels

• Seven Differential Input Channels

• Two Differential Input Channels with Optional Gain of 10x and 200x

• Optional Left Adjustment for ADC Result Readout

• 0 - V

CC ADC Input Voltage Range

• 2.7 - V

CC Differential ADC Voltage Range

• Selectable 2.56V ADC Reference Voltage

• Free Running or Single Conversion Mode

• ADC Start Conversion by Auto Triggering on Interrupt Sources

• Interrupt on ADC Conversion Complete

• Sleep Mode Noise Canceler

23.2

Overview

The ATmega64A features a 10-bit successive approximation ADC. The ADC is connected to an

8-channel Analog Multiplexer which allows eight single-ended voltage inputs constructed from

the pins of Port F. The single-ended voltage inputs refer to 0V (GND).

The device also supports 16 differential voltage input combinations. Two of the differential inputs

(ADC1, ADC0 and ADC3, ADC2) are equipped with a programmable gain stage, providing

amplification steps of 0 dB (1x), 20 dB (10x), or 46 dB (200x) on the differential input voltage

before the A/D conversion. Seven differential analog input channels share a common negative

terminal (ADC1), while any other ADC input can be selected as the positive input terminal. If 1x

or 10x gain is used, 8-bit resolution can be expected. If 200x gain is used, 7-bit resolution can be

expected.

The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is

held at a constant level during conversion. A block diagram of the ADC is shown in Figure 23-1.

The ADC has a separate analog supply voltage pin, AVCC. AVCC must not differ more than

±0.3V from V

CC. See the paragraph “ADC Noise Canceler” on page 241 on how to connect this

pin.

Internal reference voltages of nominally 2.56V or AVCC are provided On-chip. The voltage refer-

ence may be externally decoupled at the AREF pin by a capacitor for better noise performance.

ATmega64A bảng dữ liệu(PDF) 233 Page - ATMEL Corporation

ATmega64A bảng dữ liệu(HTML) 233 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

bảng dữ liệu tải về

Link URL