ATTINY84A-MF - 20MHz 8KB AVR Microcontroller | Microchip
MPN: ATTINY84A-MF ✓ ActiveATTINY84A-MF Overview
An AVR microcontroller is a compact embedded-control IC that combines a processor core, nonvolatile program memory, data memory, I/O ports, timers, and serial interfaces on one chip. Within the product hierarchy, the ATTINY84A belongs to the 8-bit AVR family, the TinyAVR class, and the broader embedded-processing and semiconductor categories. Its picoPower architecture is designed for efficient operation in small control systems where cost, board area, and energy consumption matter as much as processing capacity.
The ATTINY84A-MF provides 32 general-purpose working registers, two timer/counters with 8-bit and 16-bit operation, and two PWM channels. Its 12 I/O lines can support digital control, sensing, communication, and timing functions. The combination of 8 KB Flash, 512 bytes of EEPROM, 512 bytes of SRAM, and a 20 MHz clock allows embedded firmware to combine event handling, sensor conditioning, actuator control, and serial data exchange in one compact device.
Program development uses the AVR instruction architecture and the in-system programming interface described by Microchip for the ATtiny84A family. The manufacturer product page identifies MPLAB Snap debug and programming support through an 8-pin single in-line connector using two I/O pins and the reset line. This integration of ICSP programming and debug access supports compact boards where a dedicated connector can save space without eliminating field programming or in-circuit debugging.
Typical uses include industrial sensor nodes, compact environmental monitors, LED lighting controllers, small motor-control loops, smart accessories, and communications modules. The 12 I/O lines are particularly useful when a design needs several discrete inputs and outputs but does not require a larger 32-bit MCU. The exposed thermal pad also assists heat transfer from the device, making copper-based PCB thermal management an important part of compact, high-duty-cycle installations.
Designers should verify the complete pin assignment, exposed-pad connection, operating-voltage limits, clock requirements, and programming interface against the Microchip ATtiny24A/44A/84A datasheet. Place the decoupling capacitors close to the supply pins, preserve the required exposed-pad copper and thermal-relief pattern, and route programming signals to avoid interference from switching nodes. Confirm startup, reset, and external-clock behavior before committing the PCB layout.
This product page combines the core ATtiny84A specifications with practical programming, PCB-layout, thermal-management, and replacement guidance. It also distinguishes same-footprint family options from alternatives that require a different package, helping engineers evaluate upgrades without assuming that similar memory sizes or family names guarantee PCB compatibility.
Drop-in alternatives for ATTINY84A-MF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATTINY84A-MF (same form factor and footprint) — differing in Flash Memory, Package, SRAM, General-Purpose I/O Lines, General-Purpose Working Registers.
ATTINY44A-MF
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →ATTINY24A-MF
✅ Drop-InContact for price
View Datasheet →ATTINY441-MF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATTINY841-MUR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATTINY848-MUR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATTINY84A-MF Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit AVR RISC-based microcontroller |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 8 KB |
| EEPROM Memory | 512 bytes |
| SRAM | 512 bytes |
| General-Purpose I/O Lines | 12 |
| General-Purpose Working Registers | 32 |
| Timer/Counter Count | 2 |
| Timer Resolution | 8-bit and 16-bit |
| PWM Channels | 2 |
| Program Memory Type | In-System Programmable Flash |
| Package | 20-QFN exposed-pad, 4 x 4 mm |
| Mounting Type | Surface Mount |
| Maximum Operating Temperature | +125°C |
| Programming Interface | ICSP, 8-pin single in-line connector |
| Debug Support | MPLAB Snap compatible |
| Architecture | Enhanced AVR RISC |
| Technology | picoPower |
ATTINY84A-MF 20-qfn exposed-pad, 4 x 4 mm Pin Configuration Guide
Pin configuration for ATTINY84A-MF (20-qfn exposed-pad, 4 x 4 mm package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATTINY84A-MF.
Refer to the datasheet for full pin configuration.
Typical Applications
ATTINY84A-MF is suitable for 6 applications: Industrial Sensor Node, Environmental Monitor, LED Lighting Controller, Compact Motor Control, Smart Home Accessory, Serial Communication Module.
Industrial Sensor Node
The ATTINY84A-MF fits a compact industrial sensor node that must read several digital inputs, process an external sensor signal, and communicate status over a serial link. Its 20 MHz maximum clock provides headroom for timed acquisition and control tasks, while 8 KB of Flash allows application firmware, calibration logic, and communication handling to coexist on one MCU. The 12 general-purpose I/O lines are valuable when a node needs multiple discrete inputs for limit switches, alarms, or sensor gates. Place the QFN device near the sensor interface, use short grounded return paths, and provide local supply decoupling. The exposed pad should connect to the intended thermal and ground structure according to the manufacturer layout guidance, helping dissipate heat in enclosed industrial equipment.
Recommended
Environmental Monitor
ATTINY84A-MF is well suited to a battery- or USB-powered environmental monitor that periodically samples sensors and records or reports readings. The 512-byte SRAM supports temporary measurement and packet handling, while 512 bytes of EEPROM preserves calibration values, counters, or threshold settings when the device must retain state between power cycles. Its two timer/counters can organize sampling intervals and provide PWM output if a local indicator or actuator is required. Program the application to use the timer/counter as the time base and keep high-energy radio activity isolated from the AVR. For accurate low-power behavior, review clock and fuse options in the Microchip datasheet and ensure the QFN exposed pad has adequate copper for the expected duty cycle.
Recommended
LED Lighting Controller
The ATTINY84A-MF can control multiple LED loads in a compact lighting module because it combines 12 I/O lines with two dedicated PWM channels. One PWM channel can drive a dimmable light channel while the other handles a second dimming function or a status indicator, and the remaining GPIO lines can support pushbuttons, occupancy inputs, or fault signaling. Its 8 KB Flash capacity is useful for storing multiple lighting scenes, fade profiles, and configurable behavior. Because rapid GPIO transitions and PWM edges can create supply disturbance, route LED current through appropriate drivers rather than directly from MCU pins. Keep the MCU supply and ground return compact, decouple near the device, and isolate LED switching paths from sensitive analog or communication traces.
Recommended
Compact Motor Control
ATTINY84A-MF can serve as the command controller for a small DC motor, stepper, valve, or actuator subsystem where the MCU handles direction, limits, and timing while a dedicated power stage handles current. The two PWM channels can generate modulation or stepped-control signals, while the 16-bit timer/counter provides a convenient time base for motion sequencing. Its 8 KB Flash permits a structured state machine, soft-start behavior, and fault handling without requiring a larger processor. Keep inductive switching and motor-return currents away from the MCU traces, add appropriate flyback protection, and use the manufacturer pin descriptions to confirm whether a selected timer output remains on the same package pin in the intended operating mode.
Recommended
Smart Home Accessory
ATTINY84A-MF is practical for a small smart-home accessory that combines a local user interface, a serial communication link, and one or more controllable outputs. The 12 I/O lines can support buttons, indicator LEDs, door or presence inputs, and a relay-control signal, while 8 KB of Flash can hold a network-accessory state machine and local behaviors. Two PWM outputs can provide status feedback or a dimmable channel. For a compact enclosure, the 4 x 4 mm QFN footprint saves board area, but assembly and rework access should be considered during design. Keep switching-device heat away from the microcontroller, expose the exposed pad to a stable copper plane as specified, and route serial programming signals to accessible test pads.
Recommended
Serial Communication Module
The ATTINY84A-MF can act as the protocol and control core of a compact serial communication module. Its 20 MHz maximum clock supports efficient UART handling and event-driven firmware, while 512 bytes of SRAM is adequate for small packet buffers and protocol state. The 12 I/O lines provide the required serial, reset, interrupt, and status connections, leaving capacity for configuration or an indicator. In circuit designs that also include switching power conversion, route the serial interface away from switching nodes and confirm grounding to minimize coupling into communications. Use ICSP access for firmware updates and debugging, and verify clock-fuse settings because UART baud rate is derived from the selected system clock.
Recommended
Recommended Products Summary
Engineering reference data for ATTINY84A-MF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATTINY44A-MF | ATTINY24A-MF | ATTINY441-MF | ATTINY841-MUR | ATTINY848-MUR |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-QFN exposed-pad, 4 x 4 mm | 20-QFN exposed-pad, 4 x 4 mm | 20-QFN exposed-pad, 4 x 4 mm | 20-QFN exposed-pad, 4 x 4 mm | 20-QFN exposed-pad, 4 x 4 mm | 20-QFN exposed-pad, 4 x 4 mm |
| Flash Memory | 8 KB | 4 KB | 2 KB | 4 KB | 8 KB | 8 KB |
Key Differentiators
- Four times the program memory of ATTINY24A-MF (vs ATTINY24A-MF)
- Twice the program memory of ATTINY44A-MF (vs ATTINY44A-MF)
- Larger SRAM and EEPROM capacity within the related family (vs ATTINY24A-MF)
- More general-purpose I/O than ATTINY24A-MF (vs ATTINY24A-MF)
Design Notes
Place the ATTINY84A-MF close to its supply bypass network and route the ground return without narrow breaks. The 20-QFN exposed pad requires a deliberate thermal and electrical land pattern; use the package drawing and board-fabrication guidance rather than treating the pad as an optional mechanical feature. Keep programming, reset, and clock traces short and provide accessible test pads if production programming or debugging is required.
Decouple each applicable supply connection locally and route transient current from LEDs, motors, or relays away from the AVR. The MCU's 20 MHz operating capability does not remove the need for a quiet supply, particularly when PWM outputs drive nearby circuitry. Confirm operating-voltage limits, startup behavior, and clock-fuse requirements in the manufacturer datasheet before selecting bypass capacitance or supply tolerances.
Use the exposed pad to spread heat into the PCB and preserve surrounding copper area. For compact or enclosed installations, estimate the worst-case internal dissipation from the device operating mode and ambient temperature, then confirm that the selected copper area keeps the junction temperature within the manufacturer's limits. Avoid placing the device directly above heat-generating components, and use thermal vias only when their pattern is consistent with the manufacturer land pattern.
Do not substitute an SOIC-packaged ATtiny84A without redesigning the PCB footprint, and do not treat another TinyAVR device as interchangeable merely because it has the same memory size. Check the numbered package pins, exposed-pad connection, alternate-function mapping, timer channels, ADC channels, fuse configuration, and programming interface. The ATtiny84A-MF combines 12 I/O lines with 8 KB of Flash, so firmware capacity and peripheral mapping are both critical replacement constraints.
Compliance Information
The high-grade +125°C temperature rating is identified in the product listing, but specific RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals declarations were not stated. Confirm environmental and product certifications with the manufacturer before regulatory use.
