20 MHz AVR core in a 14-pin TSSOP
The ATTINY3224-XU is an 8-bit AVR microcontroller from Microchip's tinyAVR 2 family, clocked at 20 MHz. The 32 KB on-chip flash and 3 KB SRAM give it enough headroom for a Modbus RTU node, a sensor hub, or a simple motor controller — but the 14-pin TSSOP package limits the I/O to 12 pins, so every pin counts. The 1.8 V to 5.5 V supply range lets it run directly from a Li-ion cell or a 3.3 V / 5 V rail without an extra regulator, simplifying the power tree in battery-powered or mixed-voltage designs.
Memory and peripheral budget
The 9-channel 12-bit ADC reads thermistors, potentiometers, or current-shunt voltages; the 12-bit resolution gives about 1.2 mV per LSB at a 5 V reference, adequate for 0.1 °C temperature sensing with a 10 kΩ NTC.
Active production, ROHS3, and tube packaging
The -XU suffix indicates the ROHS3-compliant variant in a 14-lead TSSOP package, supplied in a tube — the standard for prototype and low-volume builds.
Sourcing and BOM-fit note
The 14-TSSOP footprint is a common 0.65 mm pitch, 4.40 mm body width — a two-layer board can fan out all pins, but the narrow pitch demands a controlled reflow profile to avoid solder bridging. The industrial temperature grade of -40 to 85 °C covers outdoor telecom, factory-floor sensor nodes, and automotive cabin-adjacent modules. The 85 °C ceiling excludes under-hood or engine-bay deployment without active cooling.