# ATTINY816-MNR

**Microchip Tech** · Microcontrollers (MCU/MPU/SOC) · UQFN-20-EP(3x3)

ATTINY816-MNR from Microchip Tech, in a UQFN-20-EP(3x3). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | PA2 | bidirectional | Port A bit 2, alternate functions EVOUT0, ADC0 AIN2, USART0 RxD (alternate position), SPI0 MISO (alternate position), TWI0 SCL (alternate position) and CCL LUT0-IN2; it has full asynchronous pin-change detection for interrupts and wake-up. |
| 2 | PA3 | bidirectional | Port A bit 3, alternate functions EXTCLK (external clock), ADC0 AIN3, USART0 XCK (alternate position), SPI0 SCK and TCA0 WO3; all pins can be used as event inputs and external interrupts. |
| 3 | GND | power_in | Ground reference for the device. |
| 4 | VDD | power_in | Supply voltage input; operating supply range is 1.8 V to 5.5 V per the General Operating Conditions. |
| 5 | PA4 | bidirectional | Port A bit 4, alternate functions ADC0 AIN4, PTC X0/Y0, USART0 XDIR (alternate position), SPI0 SS, TCA0 WO4, TCD0 WOA and CCL LUT0-OUT. |
| 6 | PA5 | bidirectional | Port A bit 5, alternate functions ADC0 AIN5, PTC X1/Y1, DAC0 OUT, TCA0 WO5, TCB0 WO and TCD0 WOB. |
| 7 | PA6 | bidirectional | Port A bit 6, alternate functions ADC0 AIN6, PTC X2/Y2, AC0 AINN0 and DAC0 OUT; it has full asynchronous pin-change detection for interrupts and wake-up. |
| 8 | PA7 | bidirectional | Port A bit 7, alternate functions ADC0 AIN7, PTC X3/Y3, AC0 AINP0 and CCL LUT1-OUT. |
| 9 | PB5 | bidirectional | Port B bit 5, alternate functions CLKOUT, ADC0 AIN8, AC0 AINP1 and TCA0 WO2 (alternate position). |
| 10 | PB4 | bidirectional | Port B bit 4, alternate functions ADC0 AIN9, AC0 AINN1, TCA0 WO1 (alternate position) and CCL LUT0-OUT (alternate position). |
| 11 | PB3 | passive | Port B bit 3, alternate functions TOSC1 (32.768 kHz crystal oscillator input), USART0 RxD (alternate position) and TCA0 WO0 (alternate position). |
| 12 | PB2 | passive | Port B bit 2, alternate functions TOSC2 (32.768 kHz crystal oscillator output), EVOUT1, USART0 TxD and TCA0 WO2. |
| 13 | PB1 | bidirectional | Port B bit 1, alternate functions ADC0 AIN10, PTC X4/Y4, USART0 XCK, TWI0 SDA and TCA0 WO1. |
| 14 | PB0 | bidirectional | Port B bit 0, alternate functions ADC0 AIN11, PTC X5/Y5, USART0 XDIR, TWI0 SCL and TCA0 WO0. |
| 15 | PC0 | bidirectional | Port C bit 0, alternate functions SPI0 SCK (alternate position), TCB0 WO (alternate position) and TCD0 WOC. |
| 16 | PC1 | bidirectional | Port C bit 1, alternate functions SPI0 MISO (alternate position), TCD0 WOD and CCL LUT1-OUT (alternate position). |
| 17 | PC2 | bidirectional | Port C bit 2, alternate functions EVOUT2 and SPI0 MOSI (alternate position). |
| 18 | PC3 | bidirectional | Port C bit 3, alternate functions SPI0 SS (alternate position), TCA0 WO3 (alternate position) and CCL LUT1-IN0. |
| 19 | PA0/RESET/UPDI | bidirectional | Port A bit 0 multiplexed with the RESET/UPDI pin used for reset and external programming/debug (UPDI), with alternate functions ADC0 AIN0 and CCL LUT0-IN0; the RESET/UPDI function is selected by the RSTPINCFG fuse. |
| 20 | PA1 | bidirectional | Port A bit 1, alternate functions ADC0 AIN1, USART0 TxD (alternate position), SPI0 MOSI (alternate position), TWI0 SDA (alternate position) and CCL LUT0-IN1. |
| 21 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Microchip Tech |
| Package | UQFN-20-EP(3x3) |
| Category | Embedded Processors & Controllers |
| Pins | 21 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Supply voltage |  | 1.8 |  | 5.5 | V |  | 595 |
| Operating temperature range |  | -40 |  | 105 | °C |  | 595 |
| Max CPU speed |  |  |  | 20 | MHz |  | 595 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | tin | configurations, including indium tin oxide (ITO) sensor grids. The PTC requires one pin per X-line and one pin per Y-line. | 492 |

## CAD (KiCad official)

- Symbol: `ATTINY816-MNR`
- Footprint: `Package_DFN_QFN:UQFN-20-1EP_3x3mm_P0.4mm_EP1.85x1.85mm`
- 3D model: UQFN-20-EP(3x3) (KiCad packages3D, STEP)
- 3D model files: `attiny816-mnr-etched.step` / `attiny816-mnr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `attiny816-mnr.step` / `attiny816-mnr.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Microchip Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589039702641295360) (623 pp, sha256 `77b4e8ba4cab4c02`, retrieved 2026-10-17, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/attiny816-mnr-datasheet.pdf)