ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 230

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Analog to Digital
Converter
Features
230
ATmega64(L)
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The ATmega64 features a 10-bit successive approximation ADC. The ADC is con-
nected 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 differen-
tial 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 dif-
ferential 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 108.
The ADC has a separate analog supply voltage pin, AVCC. AVCC must not differ more
than ±0.3V from V
connect this pin.
Internal reference voltages of nominally 2.56V or AVCC are provided On-chip. The volt-
age reference may be externally decoupled at the AREF pin by a capacitor for better
noise performance.
10-bit Resolution
0.5 LSB Integral Non-linearity
±2 LSB Absolute Accuracy
65 - 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
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
CC
ADC Input Voltage Range
CC
. See the paragraph “ADC Noise Canceler” on page 238 on how to
2490G–AVR–03/04