ATMEGA640V-8AU - 8MHz 64KB Flash AVR MCU 100-TQFP | Microchip
MPN: ATMEGA640V-8AU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.86 | $4.86 |
| 10 | $4.62 | $46.20 |
| 100 | $4.3 | $430.00 |
| 500 | $4.1 | $2,050.00 |
| 1,000 | $3.95 | $3,950.00 |
ATMEGA640V-8AU Overview
An 8-bit AVR microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, timers, serial interfaces, and analog peripherals on one die. Microcontrollers sit at the device level of the embedded-systems hierarchy, beneath single-board computers and above discrete logic, and are the central building block of industrial control, consumer, and IoT electronics.
Key features include 86 general purpose I/O lines, four USARTs, a byte-oriented 2-wire (I2C-compatible) serial interface, a master/slave SPI interface, a 16-channel 10-bit ADC, an on-chip analog comparator, a programmable watchdog timer with separate on-chip oscillator, and six flexible timer/counters with compare modes and PWM capability. External memory interfacing (EBI/EMI) supports system expansion.
The AVR architecture executes most instructions in a single clock cycle through a Harvard-architecture RISC pipeline with 32 general purpose working registers, delivering throughput approaching 1 MIPS per MHz. At 8MHz this yields roughly 8 MIPS, adequate for control loops, protocol bridging, and instrument firmware while consuming very little power. In-System Programmable (ISP) Flash allows firmware updates without removing the device, and the ATmega640 shares its die with the ATmega1280/2560 family, simplifying memory-size migrations.
Typical applications include industrial automation and building control nodes, low-voltage battery-powered instrumentation, motor control and LED lighting systems, and communication bridges using multiple USARTs. The wide 1.8V to 5.5V supply range makes it well suited to 2xAA/3xAA battery products.
Design consideration: the V-grade maximum clock frequency of 8MHz applies across the full voltage range; the 5V-only 16MHz ATMEGA640-16AU is the speed-upgrade path but requires at least 4.5V supply.
This page synthesizes distributor pricing, drop-in family alternatives, pinout guidance, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA640V-8AU — 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 ATMEGA640V-8AU (same form factor and footprint) — differing in Package, Timers/Counters, Watchdog Timer, Supply Voltage Range, Flash Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA640-16CUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$6.72 / Unit
View Datasheet →ATMEGA640-16AUR
✅ Drop-In✓ In Stock
$5.9 / Unit
View Datasheet →ATMEGA1280V-8AU
✅ Drop-In✓ In Stock
$12.12 / Unit
View Datasheet →ATMEGA2560V-8AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$11.3 / Unit
View Datasheet →ATMEGA1280-16AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA2560-16AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$8.87 / Unit
View Datasheet →ATMEGA640V-8AU Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Max Clock Frequency | 8 MHz |
| Flash Memory | 64 KB (32K x 16) |
| SRAM | 8 KB |
| EEPROM | 4 KB |
| Supply Voltage Range | 1.8 V to 5.5 V |
| General Purpose I/O | 86 lines |
| Timers/Counters | 6 |
| USART Interfaces | 4 |
| Serial Interfaces | SPI, 2-wire (I2C-compatible), 4x USART |
| ADC | 10-bit, 16-channel |
| Analog Comparator | Yes, on-chip |
| Watchdog Timer | Yes, with separate on-chip oscillator |
| External Memory Interface | EBI/EMI |
| Package | 100-TQFP (14 x 14 mm) |
| Mounting Type | Surface Mount |
| Program Memory Type | ISP Flash |
| Series | AVR ATmega |
| RoHS Status | Compliant |
ATMEGA640V-8AU 100-tqfp (14 x 14 mm) Pin Configuration Guide
Pin configuration for ATMEGA640V-8AU (100-tqfp (14 x 14 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 ATMEGA640V-8AU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA640V-8AU is suitable for 6 applications: Industrial Automation and Control, Battery-Powered Instrumentation, Communication Protocol Bridges, Motor Control and LED Lighting, Building and Energy Monitoring, Test and Measurement Fixtures.
Industrial Automation and Control
The ATMEGA640V-8AU fits industrial control nodes that need many I/O and multiple serial links: its 86 GPIO lines and four USARTs allow simultaneous PLC I/O scanning, MODBUS/UART field-bus communication, and operator-panel interfaces in a single low-cost MCU. Six timer/counters with compare and PWM modes generate motor or heater control waveforms, while the 16-channel 10-bit ADC samples sensors across the full 1.8V to 5.5V range. The external memory interface (EBI/EMI) extends SRAM for data logging when 8KB internal is insufficient. The watchdog timer with separate on-chip oscillator provides autonomous fault recovery in unattended factory environments. At 8MHz the AVR core delivers approximately 8 MIPS, adequate for deterministic control loops without the power draw of 32-bit alternatives.
Recommended
Battery-Powered Instrumentation
The V-grade supply range of 1.8V to 5.5V is the decisive parameter for battery instrumentation: the ATMEGA640V-8AU runs directly from 2-3 alkaline or NiMH cells without a boost converter, eliminating converter cost, board area, and quiescent loss. The AVR power-down and power-save sleep modes, combined with the programmable watchdog timer driven by a separate on-chip oscillator, allow the device to spend most of its life in microwatt-level sleep and wake on external interrupts or pin change. The 16-channel 10-bit ADC digitizes sensor arrays, and 4KB EEPROM stores calibration data across power cycles. At 8MHz the reduced dynamic current extends runtime compared with 16MHz 5V parts, making it ideal for portable data loggers and meters.
Recommended
Communication Protocol Bridges
With four USARTs plus SPI and a byte-oriented 2-wire (I2C-compatible) interface, the ATMEGA640V-8AU implements multi-protocol bridges: one USART connects to a modem or radio module, another to an RS-485 field bus, a third to a debug console, and the fourth to a GPS or sensor stream, all serviced by the AVR's UART hardware. The 8KB SRAM buffers packet payloads, and the external memory interface can add RAM for larger FIFOs. The 2-wire interface fans out to slow peripherals without consuming USARTs, while SPI handles high-speed Flash or Ethernet-module traffic. Pin-change interrupts and wake-up on any I/O line support asynchronous event handling. The 100-TQFP footprint gives enough pins to route all four buses without extensive multiplexing firmware.
Recommended
Motor Control and LED Lighting
The ATMEGA640V-8AU's six timer/counters provide multiple independent PWM channels with output-compare generation (OC0A/OC0B, OC1A/OC1B/OC1C, OC2A/OC2B, and OC3/OC4 families), enabling simultaneous control of several motors or multi-channel LED strings. The output-compare modulator and pin-change interrupts support encoder feedback and emergency-stop sensing. The 16-channel 10-bit ADC reads current-shunt voltages and potentiometer inputs for closed-loop current limiting, while the on-chip analog comparator provides fast hardware-level over-current detection independent of firmware latency. Wide 1.8V to 5.5V operation simplifies integration with logic-level MOSFET gate drivers. The 86 GPIO lines drive segment displays, relays, and status indicators alongside the PWM outputs in lighting and actuator control panels.
Recommended
Building and Energy Monitoring
Energy meters and building controllers benefit from the ATMEGA640V-8AU's balance of analog and communication resources: the 16-channel 10-bit ADC samples voltage and current channels for power calculation, the EEPROM retains energy totals through outages, and the four USARTs connect to multiple meters, a display panel, and a gateway simultaneously. The real-time counter supported by the watchdog oscillator maintains timekeeping during deep sleep, enabling interval-based metering. The external memory interface allows an external SRAM chip for rolling-load-profile storage beyond the internal 8KB. Operating from 1.8V to 5.5V permits backup-battery operation on mains failure. The mature AVR toolchain and large installed base simplify long-term firmware maintenance for regulatory-certified metering products.
Recommended
Test and Measurement Fixtures
Bench instruments and automated test fixtures exploit the ATMEGA640V-8AU's mix of ADC channels, PWM sources, and rich serial capability: the 16-channel 10-bit ADC multiplexes across dozens of test points, the timer/compare hardware produces stimulus waveforms, and a USART links the fixture to a PC controller while a second USART drives a relay or stepper sub-controller board. The 32 general purpose working registers make the single-cycle RISC core efficient for repetitive measurement loops, and 64KB Flash holds test-script interpreters or parameter tables comfortably. The external memory interface can bank-switch extended program or data storage. Its wide supply range lets a single design serve both 3.3V and 5V fixture electronics without level-shift redesign, shortening hardware spin cycles.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA640V-8AU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA640-16CUR | ATMEGA640-16AUR | ATMEGA1280V-8AU | ATMEGA2560V-8AU | ATMEGA1280-16AU | ATMEGA2560-16AU |
|---|---|---|---|---|---|---|---|
| Package | 100-TQFP (14x14 mm) | 100-TQFP - same | 100-TQFP - same | 100-TQFP - same | 100-TQFP - same | 100-TQFP - same | 100-TQFP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 128 KB | 256 KB | 128 KB | 256 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 16 KB | 16 KB | 16 KB | 16 KB |
| Max Clock Frequency | 8 MHz | 16 MHz | 16 MHz | 8 MHz | 8 MHz | 16 MHz | 16 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| EEPROM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| GPIO Count | 86 | 86 | 86 | 86 | 86 | 86 | 86 |
| Packaging Variant | Tray | Tape & Reel | Tape & Reel | Tray | Tray | Tray | Tray |
Key Differentiators
- Full-range low-voltage operation (vs ATMEGA640-16AUR)
- Lowest-cost entry to the 100-pin family (vs ATMEGA1280V-8AU)
- Multi-serial connectivity in one die (vs ATMEGA2560V-8AU)
Design Notes
The ATMEGA640V-8AU accepts 1.8V to 5.5V, but analog accuracy depends on supply quality: when using the 10-bit ADC, decouple AVCC separately from VCC with an LC filter (e.g., ferrite bead plus 100nF) and keep the ADC reference stable. If the system runs from 3.3V, verify all peripheral I/O also meets the device's VIH requirements - the AVR CMOS inputs are rail-referenced, so 3.3V logic from a 5V-supplied ATmega is fine, but 5V ATmega outputs into 3.3V-only peripherals require level shifting or series resistors. Decouple every VCC/GND pin pair on the 100-pin package with 100nF, placed within 2mm of each pin pair.
Do not exceed 8MHz on the V-grade device even at 5V supply - speed and voltage grading are linked to the silicon grade, not just the voltage. When migrating firmware between ATmega640/1280/2560 family members, update the device signature bytes and the linker memory map, and re-check bootloader interrupt vectors, since the ATmega1280/2560 have different interrupt table sizes. JTAG pins (shared with port F/G functions) default to JTAG enable - if your design uses those pins as GPIO, clear the JTAGEN fuse or you will see unexplained I/O faults. Also confirm the JTAG fuse state after any ISP firmware update.
The 14x14 mm TQFP-100 with 0.5mm lead pitch requires a fine-pitch soldering process: use a 0.15-0.18mm stencil aperture ratio and inspect for solder bridging under X-ray or AOI, since hidden shorts under the package body are common failure causes. Provide a via fan-out escape pattern on all four sides; 0.25mm vias with 0.5mm pitch escape routing are standard for this footprint. Keep the ISP header and JTAG connector routing short and away from switching nodes, and reserve PG0/PG1 (/WR /RD) lines accessible if the external memory interface may be used in future board revisions.
At 8MHz the AVR is not aggressive from an EMI standpoint, but the 100-pin package drives many simultaneous outputs: add 22-33 ohm series resistors on long lines to cables (USARTs, SPI to external modules) to control ringing and radiated emissions. Route the crystal (if used) with short traces, ground-guarded, close to the XTAL pins, and do not run fast digital signals under the crystal. Group the four USARTs toward board edges and keep SPI clock lines away from the ADC analog front-end to preserve 10-bit accuracy.
Compliance Information
RoHS compliance per standard Microchip ATmega product listings; REACH and conflict-minerals status not stated in the provided web data - verify on the Microchip product page.
