Datasheet
2018 Microchip Technology Inc. Data Sheet Complete DS40002060A-page 91
ATtiny4/5/9/10
14. Analog to Digital Converter
14.1 Features
• 8-bit Resolution
• 0.5 LSB Integral Non-linearity
• 1 LSB Absolute Accuracy
• 65µs Conversion Time
• 15 kSPS at Full Resolution
• Four Multiplexed Single Ended Input Channels
• Input Voltage Range: 0 – V
CC
• Supply Voltage Range: 2.5V – 5.5V
• Free Running or Single Conversion Mode
• ADC Start Conversion by Auto Triggering on Interrupt Sources
• Interrupt on ADC Conversion Complete
• Sleep Mode Noise Canceler
14.2 Overview
ATtiny5/10 feature an 8-bit, successive approximation ADC. The ADC is connected to a 4-channel analog multiplexer
which allows four single-ended voltage inputs constructed from the pins of port B. 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 Figure 14-1 on page 92.
Internal reference voltage of V
CC
is provided on-chip.
The ADC is not available in ATtiny4/9.
14.3 Operation
In order to be able to use the ADC the Power Reduction bit, PRADC, in the Power Reduction Register must be disabled.
This is done by clearing the PRADC bit. See “PRR – Power Reduction Register” on page 36 for more details.
The ADC is enabled by setting the ADC Enable bit, ADEN in “ADCSRA – ADC Control and Status Register A”. Input chan-
nel selections will not go into effect until ADEN is set. The ADC does not consume power when ADEN is cleared, so it is
recommended to switch off the ADC before entering power saving sleep modes.
The ADC converts an analog input voltage to an 8-bit digital value using successive approximation. The minimum value
represents GND and the maximum value represents the voltage on V
CC
.
The analog input channel is selected by writing MUX1:0 bits. See “ADMUX – ADC Multiplexer Selection Register” on page
101. Any of the ADC input pins can be selected as single ended inputs to the ADC.
The ADC generates an 8-bit result which is presented in the ADC data register. See “ADCL – ADC Data Register” on page
103.
The ADC has its own interrupt request which can be triggered when a conversion completes.