ATTINY25-20SUR Atmel, ATTINY25-20SUR Datasheet - Page 126

• Manufacturer Part Number: ATTINY25-20SUR
• Description: MCU AVR 2KB FLASH 20MHZ 8SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY25-20SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 6
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17. Analog to Digital Converter
17.1
17.2
126
Features
Overview
ATtiny25/45/85
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The ATtiny25/45/85 features a 10-bit successive approximation Analog to Digital Converter
(ADC). The ADC is connected to a 4-channel Analog Multiplexer which allows one differential
voltage input and four single-ended voltage inputs constructed from the pins of Port B. The dif-
ferential input (PB3, PB4 or PB2, PB5) is equipped with a programmable gain stage, providing
amplification step of 26 dB (20x) on the differential input voltage before the A/D conversion. The
single-ended voltage inputs refer to 0V (GND).
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
on page
Internal voltage references of nominally 1.1V or 2.56V are provided On-chip. The Internal volt-
age reference of 2.56V can optionally be externally decoupled at the AREF (PB0) pin by a
capacitor, for better noise performance. Alternatively, V
single ended channels. There is also an option to use an external voltage reference and turn-off
the internal voltage reference. These options are selected using the REFS[2:0] bits of the
ADMUX control register.
10-bit Resolution
1 LSB Integral Non-linearity
± 2 LSB Absolute Accuracy
65 - 260 µs Conversion Time
Up to 15 kSPS at Maximum Resolution
Four Multiplexed Single Ended Input Channels
Two differential input channels with selectable gain
Temperature sensor input channel
Optional Left Adjustment for ADC Result Readout
0 - V
Selectable 1.1V / 2.56V ADC Voltage Reference
Free Running or Single Conversion Mode
ADC Start Conversion by Auto Triggering on Interrupt Sources
Interrupt on ADC Conversion Complete
Sleep Mode Noise Cancele
Unipolar / Bibilar Input Mode
Input Polarity Reversal Mode
CC
127.
ADC Input Voltage Range
CC
can be used as voltage reference for
2586M–AVR–07/10
Figure 17-1