ATMEGA3290P-20AUR - AVR 8-Bit MCU 32KB 20MHz | Microchip
MPN: ATMEGA3290P-20AUR ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATMEGA3290P-20AUR Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, making it a staple of the wider MCU hierarchy: microcontroller unit -> embedded processor -> semiconductor. The AVR ATmega family sits within Microchip's low-power CMOS portfolio, and the 'P' suffix in ATMEGA3290P denotes the picoPower-optimized die for low active and sleep currents.
Key features include 130 powerful instructions, most executed in one clock cycle; 32 general-purpose working registers; read-while-write self-programming Flash; an on-chip LCD controller/driver suited to segmented glass displays; and In-Circuit Serial Programming (ICSP) with on-chip debug via JTAG. The 20 MHz rating enables 20 MIPS peak throughput at 5 V.
The picoPower technology reduces power consumption in idle, power-save, power-down, and standby sleep modes, while the wide 2.7V to 5.5V supply range supports both 3.3V and 5V designs, with 5V operation required to reach the full 20 MHz speed grade.
Typical applications include industrial HMI panels with segmented LCDs, battery-powered instruments and meters, building and HVAC controllers, and consumer appliances where the 69 GPIO lines drive keys, LEDs, relays, and displays from a single chip.
When designing with this device, remember that the 20 MHz grade is only guaranteed across the full industrial range at 4.5V to 5.5V; at 3.3V the safe maximum clock is lower per the frequency-versus-voltage curve in the datasheet.
This page synthesizes verified distributor data, drop-in ATmega family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA3290P-20AUR — 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 ATMEGA3290P-20AUR (same form factor and footprint) — differing in Package, RoHS Status, LCD Controller, Supply Voltage Range, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA3250P-20AU
✅ Drop-In✓ In Stock
$1.8 / Unit
View Datasheet →ATMEGA3250PA-AUR
✅ Drop-In✓ In Stock
$2.98 / Unit
View Datasheet →ATMEGA3290V-8AUR
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →ATMEGA3250V-8AUR
✅ Drop-In✓ In Stock
$3.38 / Unit
View Datasheet →ATMEGA3290-16AI
✅ Drop-In✓ In Stock
$4.14 / Unit
View Datasheet →ATMEGA3290P-20AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC CMOS |
| Program Memory (Flash) | 32 KB (16K x 16) ISP, read-while-write |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Peak Performance | 20 MIPS (approx. 1 MIPS/MHz) |
| Instruction Set | 130 instructions, most single-cycle |
| General-Purpose I/O | 69 lines |
| Working Registers | 32 |
| Supply Voltage Range | 2.7 V to 5.5 V |
| LCD Controller | Yes, on-chip segment LCD driver |
| Debug / Programming | JTAG on-chip debug, ICSP self-programming |
| Low-Power Technology | picoPower |
| Package | 100-TQFP (14x14 mm) |
| Operating Temperature | -40C to +85C (industrial) |
| Mounting Type | Surface Mount |
| Packing | Tape & Reel (R suffix) |
| RoHS Status | Green / RoHS compliant per distributor data |
ATMEGA3290P-20AUR 100-tqfp (14x14 mm) Pin Configuration Guide
Pin configuration for ATMEGA3290P-20AUR (100-tqfp (14x14 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 ATMEGA3290P-20AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA3290P-20AUR is suitable for 6 applications: Industrial HMI and Operator Panels, Battery-Powered Utility Meters, HVAC and Building Controllers, Consumer Appliance Control, Instrumentation and Test Equipment, Security and Access Control Panels.
Industrial HMI and Operator Panels
The ATMEGA3290P-20AUR fits industrial operator panels because its 69 GPIO lines drive keypads, LEDs, and relays while the on-chip segment LCD controller renders display content without an external LCD driver IC. At 20 MHz the AVR core executes roughly 20 MIPS, ample for scan loops, debounce logic, and MODBUS-style serial polling. Deployed between a 5V industrial rail with local 100nF decoupling per VCC pin, it replaces a discrete MCU plus LCD driver combination, cutting BOM cost. The trade-off is that only segment LCDs are supported; graphic displays need an external controller.
Recommended
Battery-Powered Utility Meters
Utility meters run for years on batteries, and the ATMEGA3290P-20AUR's picoPower technology keeps sleep currents in the microamp range while the segment LCD stays visible. The 1 KB EEPROM stores calibration and consumption records through power cycles, and the 2.7V floor allows operation down to two-cell or lithium-thionyl-chloride supplies. Firmware typically sleeps in power-save mode with an RTC-based wake, samples the sensing front end via ADC, and returns to sleep. Use the V-8 grade (ATMEGA3290V-8AUR, drop-in same footprint) if the 3.3V rail makes a 20 MHz clock unsafe.
Recommended
HVAC and Building Controllers
Building automation nodes need many I/O for dampers, valves, fans, and sensors - exactly the 69-line GPIO budget of the ATMEGA3290P-20AUR. The 32 KB Flash holds communication stacks and control loops with room for field firmware updates via self-programming bootloader, and JTAG enables on-chip debug during commissioning. Running from a 24V-derived 5V rail at 20 MHz, the core handles PID loops and sensor scanning comfortably. Designers should respect the frequency-versus-voltage curve and add transient protection on field-wired GPIO lines exposed to industrial environments.
Recommended
Consumer Appliance Control
Washing machines, dishwashers, and cooking appliances combine segmented displays, touch keys, motor control outputs, and safety interlocks - a profile the ATMEGA3290P-20AUR addresses with its LCD controller, 69 GPIO, and 32 KB Flash. At 20 MHz and 5V, single-cycle instruction execution gives deterministic timing for zero-cross motor triac firing and buzzer tone generation. The industrial -40C to +85C rating covers unventilated appliance enclosures. Cost-sensitive designs may use the non-picoPower ATMEGA3290-16AI drop-in at 16 MHz where the lower speed suffices.
Recommended
Instrumentation and Test Equipment
Bench instruments and portable testers benefit from the ATMEGA3290P-20AUR's combination of segment LCD display control, EEPROM parameter storage, and JTAG debug during development. The 20 MHz core at 5V provides roughly 20 MIPS for menu systems, ADC averaging, and serial telemetry over UART. Read-while-write Flash allows firmware to log results to the 1 KB EEPROM without halting execution. Because precision front ends are analog, place the MCU away from the analog section and use its power-down mode between measurements to keep self-heating and battery drain low.
Recommended
Security and Access Control Panels
Access-control keypads and alarm panels need display, buzzer, relay, and extensive key-scan I/O - all within the 69 GPIO and LCD capability of the ATMEGA3290P-20AUR. Its 32 KB Flash accommodates secure code with CRC checking, and the EEPROM retains user codes and event counters across outages. Operating from a standby-battery-backed 5V supply, picoPower sleep modes keep panel idle current minimal. The JTAG port should be fuse-disabled in production to protect firmware IP, per the AVR lock-bit feature set documented by Microchip.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA3290P-20AUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA3250P-20AU | ATMEGA3250PA-AUR | ATMEGA3290V-8AUR | ATMEGA3290-16AI |
|---|---|---|---|---|---|
| Package | 100-TQFP (14x14) | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| Max Clock | 20 MHz | 20 MHz | 20 MHz | 8 MHz | 16 MHz |
| picoPower Die | Yes (P suffix) | Yes | Yes (PA enhanced) | No (V low-voltage die) | No (legacy die) |
| LCD Controller | Yes | Yes | Yes | Yes | Yes |
| Temperature Range | -40C to +85C (industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C (I grade) |
Key Differentiators
- picoPower die for lowest sleep current (vs ATMEGA3290-16AI)
- 20 MHz full-speed grade (vs ATMEGA3290V-8AUR)
- Segment LCD controller on chip (vs ATMEGA324P-20AUR)
- Trade-off: no automotive qualification (vs ATMEGA3250PA-AUR)
Design Notes
The 20 MHz grade is only valid at the upper supply range. Per the AVR frequency-versus-voltage curve, a 20 MHz clock at 3.3V is out of specification and can cause marginal execution at temperature extremes. If your system rail is 3.3V, either drop the clock to the curve-safe value or switch to the V-grade drop-in (ATMEGA3290V-8AUR, 8 MHz, wider low-voltage range) on the same TQFP-100 footprint.
Place 100 nF ceramic decoupling capacitors at every VCC/AVCC/UVCC pin pair, as close to the package as possible, plus one bulk 10 uF capacitor per rail. The 100-TQFP center-feed power pins make fanout critical - use dedicated power planes or a star topology from the entry point. Keep the internal LCD voltage rails (if used for the segment LCD bias) on a quiet, guarded PCB island to prevent ghost segments.
JTAG pins (shared with port C) default to JTAG function after reset; if your application uses PC2-PC5 as GPIO, clear the JTAGEN fuse or disable JTAG in software, or the port will not behave as expected. Also remember lock bits disable JTAG debug permanently once set - prototype before locking production firmware. EEPROM wear: the 1 KB EEPROM is rated 100k erase/write cycles per cell, so avoid re-writing calibration data in loops.
Estimated: at 5V/20 MHz full activity, AVR ATmega current draw is on the order of 15-20 mA, giving roughly 75-100 mW dissipation in a 100-TQFP (14x14 mm) package with theta_JA near 40-50 C/W - under 5 C junction rise. No heatsink or special copper is required; normal SMT assembly on a standard 4-layer or 2-layer board is sufficient.
Compliance Information
FindIC distributor data lists the part as GREEN (RoHS-compliant, halogen-free) packaging. REACH and conflict-minerals status not stated in provided data.