ATMEGA640V-8CUR - 8MHz AVR 64KB MCU 100-CBGA | Microchip
MPN: ATMEGA640V-8CUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.75 | $4.75 |
| 10 | $4.45 | $44.50 |
| 100 | $4.3 | $430.00 |
| 500 | $4.15 | $2,075.00 |
| 1,000 | $4.02 | $4,020.00 |
ATMEGA640V-8CUR Overview
An 8-bit microcontroller (MCU) is an integrated circuit that combines a processor core, memory, and peripherals on a single die, executing one instruction per clock cycle in the AVR RISC architecture. MCUs sit at the lowest level of the embedded system hierarchy - above discrete logic and below application processors - and are the workhorse of industrial control, instrumentation, and consumer electronics. The ATmega640 belongs to the megaAVR family, the large-pin-count branch of the AVR product line.
Key features include 64 KB of self-programmable ISP Flash, 86 general purpose I/O lines, 32 general purpose working registers, a real-time counter, six flexible timer/counters, and in-circuit serial programming (ICSP) via just two device I/O pins plus reset. The V-suffix device supports the extended low-voltage operating range (1.8 V minimum), enabling battery-powered and low-voltage industrial designs.
Architecturally, the AVR core executes most instructions in a single clock cycle through a Harvard-architecture pipeline with separate program and data buses, giving high code efficiency and deterministic timing. The device integrates JTAG-based on-chip debugging and supports the MPLAB Snap programmer through the 8-pin SIL ICSP connector.
Typical applications include industrial automation controllers, building management nodes, instrumentation front ends, and battery-operated monitoring systems where the wide 1.8 V to 5.5 V supply range and low-power sleep modes are decisive.
Design consideration: clock speed derates with supply voltage - 8 MHz is safe across the full 1.8 V to 5.5 V range, but verify the voltage-frequency curve if migrating to the 16 MHz ATMEGA640 variants.
This page synthesizes distributor pricing, same-package drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with pricing as of 2026-09-18.
Drop-in alternatives for ATMEGA640V-8CUR — 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-8CUR (same form factor and footprint) — differing in Flash Memory, Program Memory Size, Program Memory Type, Package, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA640-16CUR
✅ Drop-In✓ In Stock
$6.72 / Unit
View Datasheet →ATMEGA640V-8CU
✅ Drop-In✓ In Stock
$8.36 / Unit
View Datasheet →ATMEGA1280-16CUR
✅ Drop-In✓ In Stock
$6.25 / Unit
View Datasheet →ATMEGA2560V-8CUR
✅ Drop-In✓ In Stock
$6.12 / Unit
View Datasheet →ATMEGA640V-8CUR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 8 MHz |
| Program Memory Type | FLASH |
| Program Memory Size | 64 KB (32K x 16) |
| RAM Size | 8 KB |
| EEPROM Size | 4 KB |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Number of I/O | 86 |
| General Purpose Working Registers | 32 |
| Timers/Counters | 6 flexible timer/counters |
| Real-Time Counter | Yes |
| Operating Temperature | -40C to +85C (TA) |
| Package | 100-CBGA (9x9 mm) |
| Mounting Type | Surface Mount |
| Programming Interface | ICSP (In-Circuit Serial Programming) |
| Data Bus Width | 8 Bit |
ATMEGA640V-8CUR 100-cbga (9x9 mm) Pin Configuration Guide
Pin configuration for ATMEGA640V-8CUR (100-cbga (9x9 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-8CUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA640V-8CUR is suitable for 6 applications: Industrial Automation Controllers, Battery-Powered Monitoring Systems, Instrumentation and Test Equipment, Building Management and HVAC Control, Motor Control and Actuation, Legacy Board Redesign and BOM Continuity.
Industrial Automation Controllers
The ATMEGA640V-8CUR fits industrial automation nodes because its 86 general purpose I/O lines and six timer/counters can drive relays, stepper sequences, and encoder inputs without external port expanders, and the AVR single-cycle RISC core provides deterministic 8 MHz timing for control loops. In a PLC expansion module, the MCU typically handles digital I/O scanning and Modbus-style UART communication while a supervisor handles safety. The wide 1.8 V to 5.5 V supply range tolerates noisy industrial rails, and the -40C to +85C temperature rating covers cabinet environments. The trade-off versus a 16 MHz part is halved computation headroom, so reserve the 8 MHz V-grade for designs whose interrupt budget is verified below roughly 50% CPU load.
Recommended
Battery-Powered Monitoring Systems
The 1.8 V to 5.5 V operating range is the decisive parameter for battery designs: the ATMEGA640V-8CUR runs directly from two NiMH/alkaline cells or a single-cell lithium rail without a boost converter, and AVR power-down sleep modes drop current to microamp levels while the real-time counter keeps timekeeping. A typical sensor logger uses the six timers for periodic sampling, the 4 KB EEPROM for calibration data, and the 8 KB SRAM for ring buffers between radio transmissions. Using the 8 MHz V-grade instead of a 16 MHz standard part reduces dynamic switching current across the whole discharge curve. The engineering trade-off is that at 1.8 V the MCU must remain clocked at or below 8 MHz, so heavy DSP-style processing is not feasible on this grade.
Recommended
Instrumentation and Test Equipment
Bench instruments benefit from the ATmega640's combination of 64 KB self-programmable Flash for field-updatable firmware, 4 KB EEPROM for calibration constants, and JTAG on-chip debugging for deterministic bring-up. The 86 I/O lines interface front-panel keys, displays, and relay-switched signal paths, while hardware USARTs handle remote control protocols. In a data-acquisition front end, the MCU sequences an external ADC and streams results over UART or SPI; the 8 MHz clock limits sample-rate coordination but is ample for human-interface-class instruments. The CBGA-100 footprint gives a compact 9x9 mm replacement for older TQFP-based boards when re-spinning for area savings, and the V-grade's wide supply range simplifies dual-rail analog designs.
Recommended
Building Management and HVAC Control
HVAC controllers use the ATMEGA640V-8CUR for fan staging, damper actuation, and temperature network integration, exploiting the 86 I/O lines to drive triacs and read NTC sensor dividers directly. The real-time counter plus a 32.768 kHz crystal supports time-of-use scheduling, and the 4 KB EEPROM holds setpoints and fault logs through power cycles. The -40C to +85C rating covers rooftop unit enclosures, and the 1.8 V minimum supply allows the same PCB to be reused across 3.3 V and 5 V product variants. Communication over TWI or USART links to room units keeps the BOM single-chip. The design consideration is watchdog supervision: the megaAVR watchdog timer must be enabled in field units to recover from EMI-induced lockups in motor-switching environments.
Recommended
Motor Control and Actuation
With six flexible timer/counters, the ATmega640 generates multiple PWM channels with hardware phase/frequency control suitable for DC motor and stepper actuation, while quadrature encoder inputs are handled in interrupt-driven firmware at 8 MHz. The 86 GPIO lines drive H-bridge enable, direction, and current-sense multiplexing, and the CBGA-100 package places motor interface pins with short return paths to the ground ball array. The wide supply range lets the same controller serve 3.3 V logic and 5 V gate-driver domains. For brushed DC drives under 24 V, the single-chip approach replaces discrete logic and reduces EMI redesign cycles. The key constraint is CPU bandwidth: PWM plus commutation interrupts at 8 MHz must be profiled, and higher-speed motor control should migrate to the ATMEGA640-16CUR drop-in.
Recommended
Legacy Board Redesign and BOM Continuity
Many legacy products specify the ATmega640 family in TQFP-100 or CBGA-100; the ATMEGA640V-8CUR serves as the low-voltage CBGA continuity part when the original speed grade was 8 MHz. Because the ATmega640/1280/2560 die shares one datasheet and one footprint across memory sizes, a single PCB can be populated with 64 KB, 128 KB, or 256 KB variants to serve multiple SKUs - a common sourcing hedge against allocation. Firmware written for earlier megaAVR parts ports with minimal changes, and the ICSP programming interface (two I/O pins plus reset, per Microchip documentation) is compatible with MPLAB Snap and third-party ISP programmers. Verifying the 9x9 mm CBGA land pattern against the datasheet mechanical drawing is the main re-spin task.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA640V-8CUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA640-16CUR | ATMEGA640V-8CU | ATMEGA1280-16CUR | ATMEGA2560V-8CUR |
|---|---|---|---|---|---|
| Package | 100-CBGA (9x9 mm) | 100-CBGA (9x9 mm) - same | 100-CBGA (9x9 mm) - same | 100-CBGA (9x9 mm) - same | 100-CBGA (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 128 KB | 256 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| EEPROM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| Max Clock Speed | 8 MHz | 16 MHz | 8 MHz | 16 MHz | 8 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V | approx 2.7 V to 5.5 V | 1.8 V to 5.5 V | approx 2.7 V to 5.5 V | 1.8 V to 5.5 V |
| General Purpose I/O | 86 | 86 | 86 | 86 | 86 |
Key Differentiators
- Lowest supply voltage in the CBGA-100 ATmega640 family (vs ATMEGA640-16CUR)
- Same-footprint Flash headroom upgrade path (vs ATMEGA2560V-8CUR)
- Cost-optimized 64 KB entry point (vs ATMEGA1280-16CUR)
Design Notes
Respect the AVR voltage-frequency derating curve: the ATMEGA640V-8CUR is guaranteed to 8 MHz across 1.8 V to 5.5 V, but this is also its ceiling. If the design later needs a crystal above 8 MHz, migrate to the ATMEGA640-16CUR and verify the minimum supply rises to roughly 2.7 V. Add 100 nF decoupling on each VCC/AVCC ball pair plus bulk 10 uF, and keep the analog supply filtered through an LC or ferrite bead when using the ADC.
CBGA-100 (9x9 mm) requires an accurate 1.0 mm-pitch ball land pattern taken directly from the datasheet mechanical drawing; do not scale from a TQFP-100 footprint. Because balls are hidden after reflow, plan AOI or X-ray inspection and use a solder-mask-defined pad per the drawing to control ball collapse. Fill unused area between ball fields with ground plane and stitch vias to reduce ground bounce on the 86 I/O lines during simultaneous switching.
The UR suffix denotes reel packing and the C suffix the CBGA temperature package - do not substitute TQFP variants (e.g., ATMEGA640V-8AU) on the same footprint; they are not pin-compatible. Enable the watchdog timer in production firmware, since the megaAVR has no brown-out-driven latch protection by default unless the BOD fuse is programmed. Fuse settings for clock source and JTAGEN are the most common cause of field programming failures - dump and archive fuses from a known-good board before reflowing replacements.
Compliance Information
Compliance data not present in the provided web data; verify on the Microchip product page for the specific top marking and date code.
