ATtiny24/44/84 Datasheet, Pinout, Minimal Circuit, Maximum Frequency Calculator

The ATtiny24/44/84 have 12 programmable I/O pins, and run off of an internal 8MHz RC oscillator. They have no USART for serial communication, but provide a USI block which can be used as a USART in a pinch. 8 ADC channels and 2 timers are included as well.

The ATtinyx4 has several clock options, including an internal clock that runs at 128kHz, or an RC clock that runs 8MHz along with a divide by 8 fuse. The maximum frequency is 20MHz with an external crystal. The default is 8MHz divided by 8, or 1MHz. The fuse sets the divisor at reset time - you can change the divisor programmatically at any time.

Power Supply vs. Maximum Frequency

The maximum clock frequency is dependent on the power supply voltage, and the calculator below can help you determine the maximum clock frequency at any power supply voltage.

Maximum Frequency Calculator for ATtiny24/44/84

ATtiny24/44/84 Features
Flash 2k4k8k
EEPROM 128B256B512B
RAM 128B256B512B
I/O Pins 12
Interrupts 17
ADC Channels 8
RT Counter (w/osc)0
Timers (8-bit) 1
Timers (16-bit) 1
PWM (8-bit) 2
PWM (16-bit) 2
Price (1's) $1.14$1.30$1.41
Power Consumption (approximate) 1mA + (0.58mA/MHz)
Maximum I/O Current (per pin) 40mA
Maximum I/O Current (all ports) 100mA
Maximum I/O Current (total) 200mA

ATtiny24/44/84 Datasheet

Link to ATtiny24/44/84 datasheet from Atmel's website.

ATtiny24/44/84 Pinout

ATtiny24-PU pinout

ATtiny24-AU pinout

ATtiny24/44/84 "Minimal" Circuit Diagram

The circuit below shows a programming port, reset circuit, and a crystal oscillator. Any or all of these could be left off and the device would function perfectly well.

ATtiny24/44/84 minimal schematic diagram