# ATTINY45-20SUR

**Microchip Tech** · Microcontrollers (MCU/MPU/SOC) · SOIC-8-208mil

ATTINY45-20SUR from Microchip Tech, in a SOIC-8-208mil. 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 | PB5 | bidirectional | Port B bit 5 is a bidirectional I/O pin with a selectable internal pull-up that is tri-stated during reset; as RESET, a low level held longer than the minimum pulse length (Table 21-4, page 165) generates a device reset, and the pin can also be used as a weak I/O pin. |
| 2 | PB3 | bidirectional | Port B bit 3 is a bidirectional I/O pin with selectable internal pull-up that also serves as XTAL1/CLKI, OC1B and ADC3 alternate functions. |
| 3 | PB4 | bidirectional | Port B bit 4 is a bidirectional I/O pin with selectable internal pull-up that also serves as XTAL2/CLKO, OC1B and ADC2 alternate functions. |
| 4 | GND | power_in | Ground reference for the device. |
| 5 | PB0 (MOSI/DI/SDA/AIN0/OC0A/OC1A/AREF/PCINT0) | bidirectional | Port B bit 0 is a bidirectional I/O pin with selectable internal pull-up that also serves as MOSI/DI/SDA, AIN0, OC0A, OC1A, AREF and PCINT0 alternate functions. |
| 6 | PB1 (MISO/DO/AIN1/OC0B/OC1A/PCINT1) | bidirectional | Port B bit 1 is a bidirectional I/O pin with selectable internal pull-up that also serves as MISO/DO, AIN1, OC0B, OC1A and PCINT1 alternate functions. |
| 7 | PB2 (SCK/USCK/SCL/ADC1/T0/INT0/PCINT2) | bidirectional | Port B bit 2 is a bidirectional I/O pin with selectable internal pull-up that also serves as SCK/USCK/SCL, ADC1, T0, INT0 and PCINT2 alternate functions. |
| 8 | VCC | power_in | Supply voltage; the Features list gives 2.7 - 5.5 V for ATtiny45 (20 MHz speed grade at 4.5 - 5.5 V). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Microchip Tech |
| Package | SOIC-8-208mil |
| Category | Embedded Processors & Controllers |
| Pins | 8 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Operating voltage (non-V ATtiny25/45/85) | VCC | 2.7 |  | 5.5 | V | ATtiny25/45/85 (not V variant), 20 MHz speed grade part | 1 |
| Clock frequency (speed grade) |  | 0 |  | 10 | MHz | VCC 2.7 - 5.5V | 1 |
| Clock frequency (speed grade) |  | 0 |  | 20 | MHz | VCC 4.5 - 5.5V | 1 |
| Operating temperature range (Industrial) |  | -40 |  | 85 | C | Industrial, ordering code ATtiny45-20SUR (-40C to +85C) | 12 |

## 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 | 3. Code indicators: H = NiPdAu lead finish, U/N = matte tin, R = tape & reel. 4. Can also be supplied in wafer form. Contact your local Atmel sales office for ordering information and minimum quantiti | 11 |

## CAD (KiCad official)

- Symbol: `ATTINY45-20SUR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8-208mil (KiCad packages3D, STEP)
- 3D model files: `attiny45-20sur-etched.step` / `attiny45-20sur-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `attiny45-20sur.step` / `attiny45-20sur.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/8586199984383803392) (30 pp, sha256 `80124a2d9a6f0385`, retrieved 2026-10-20, 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/attiny45-20sur-datasheet.pdf)