atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 311

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

25. Analog to Digital Converter - ADC
25.1
7766A–AVR–03/08
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
The ATmega32U4 features a 10-bit successive approximation ADC. The ADC is connected to
an 12-channel Analog Multiplexer which allows six single-ended voltage inputs constructed from
the pins of Port A, and three others from PortB and three others from PortD. The single-ended
voltage inputs refer to 0V (GND).
The device also supports 32 differential voltage input combinations, thanks to a differential
amplifier equipped with a programmable gain stage, providing amplification steps of 0 dB (1x),
10 dB (10x), 16dB (40x) or 23dB (200x) on the differential input voltage before the A/D conver-
sion. Two differential analog input channels share a common negative terminal (ADC0/ADC1),
while any other ADC input can be selected as the positive input terminal. If 1x, 10x or 40x 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
The ADC has a separate analog supply voltage pin, AV
0.3V from V
pin.
Internal reference voltages of nominally 2.56V or AV
ence 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
Twelve Multiplexed Single-Ended Input Channels
One Differential amplifier providing gain of 1x - 10x - 40x - 200x
Temperature sensor
Optional Left Adjustment for ADC Result Readout
0 - V
Selectable 2.56 V 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 319
CC
are provided On-chip. The voltage refer-
CC
. AV
CC
must not differ more than ±
ATmega32U4
on how to connect this
Figure
25-1.
311