ATMEGA3290A-AU - 8-bit AVR MCU 32KB Flash LCD | Microchip
MPN： ATMEGA3290A-AU ✓ 啟用中ATMEGA3290A-AU 概覽
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor in the broader microcontroller (MCU) hierarchy: microcontroller -> embedded processor -> system-on-chip building block. AVR devices execute most of their 130 powerful instructions in a single clock cycle, and the ATmega family adds in-system programmable (ISP) Flash with read-while-write support, making field firmware updates straightforward without a separate programmer socket.
Key features of the ATMEGA3290A-AU include 69 general-purpose I/O lines, 32 general-purpose working registers, a JTAG interface for boundary-scan, on-chip debugging and programming, and a complete on-chip LCD controller with internal contrast control. The internal oscillator option reduces external component count, while three flexible timers (two 8-bit with separate prescaler and compare mode, one 16-bit) cover PWM, capture, and timing tasks.
Technically, the ATmega3290A belongs to the ATmega3290/3290P/6490 LCD megAVR family. The advanced RISC pipeline delivers close to 20 MIPS at 20 MHz, and the LCD driver directly drives segment glass for metering and human-machine interface panels, removing the need for an external LCD controller. EEPROM retention and ISP Flash endurance support data logging and frequent firmware updates in industrial products.
Typical applications include utility metering displays, industrial HMI panels with segmented LCDs, building automation keypads, and battery-powered instrumentation where the low-power AVR core and integrated LCD driver minimize board area and quiescent current.
When designing with this part, confirm the exact operating voltage range and LCD bias configuration against the manufacturer datasheet, and reserve JTAG header access for in-circuit debug. Note the distinction between the 'A' (standard) and 'P'/'PA' (picoPower) variants when sleep current is critical.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 ATMEGA3290A-AU — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA3290A-AU （相同外形與佔位） — 差異在於 Package, Number of I/O, Supply Voltage Range, Operating Temperature, RAM Size.
ATMEGA3290P-AU
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ATMEGA3290PA-AU
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA6490A-AU
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA6450A-AU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA3250P-20AU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA3250PA-AUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA3250V-8AUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA3290A-AU 最大額定值與電氣特性
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 20 MHz |
| Program Memory Size | 32KB (16K x 16) FLASH |
| RAM Size | 2K x 8 SRAM |
| EEPROM Size | 1KB |
| Number of I/O | 69 |
| Working Registers | 32 general purpose |
| Instructions | 130 powerful instructions, most single-cycle |
| LCD Controller | On-chip, up to 4 x 40 segments, internal contrast control |
| Timers | Two 8-bit with prescaler/compare, one 16-bit |
| Debug/Programming Interface | JTAG (boundary-scan, on-chip debug and programming) |
| Oscillator Type | Internal |
| 封裝 / 外殼 | 100-TQFP (14x14 mm) |
| 工作溫度 | Industrial range |
| 安裝類型 | Surface Mount |
| Packaging | Tape & Reel (TR) |
ATMEGA3290A-AU 100-tqfp (14x14 mm) 腳位配置指南
ATMEGA3290A-AU（100-tqfp (14x14 mm) 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： ATMEGA3290A-AU.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA3290A-AU 適用於 6 應用s: Utility Metering Displays, Industrial HMI Control Panels, Battery-Powered Portable Instruments, Building Automation Keypads and Thermostats, POS and Vending Machine Displays, Automotive and White-Goods Cluster Displays.
Utility Metering Displays
Electricity, water, and gas meters require a low-power MCU that can directly drive segmented LCD glass. The ATMEGA3290A-AU's on-chip LCD controller supports up to 4x40 = 160 segments with internal contrast control, so a 7-digit plus icon display is handled without an external LCD driver IC, cutting BOM cost and board area. The 1KB EEPROM stores calibration constants and billing data through power cycles, while the 20 MHz AVR core executes metering arithmetic between LCD refresh frames. Placed as the single main MCU with the LCD biased from internal contrast control, the design benefits from read-while-write Flash for field firmware updates and 69 GPIO lines for pulse inputs, tamper switches, and communication UARTs.
推薦
Industrial HMI Control Panels
Factory and building-automation control panels combine segmented LCDs, keypads, relays, and status LEDs - a load profile that matches the ATMEGA3290A-AU well. Its 69 general-purpose I/O lines natively cover a matrix keypad, backlight control, and relay drivers without port expanders, while the integrated 4x40 segment LCD controller with internal contrast control renders setpoints and alarms. Two 8-bit timers with separate prescaler and compare mode handle keypad debounce and PWM backlight dimming, and the 16-bit timer generates precise communication timing. JTAG on-chip debugging allows field service teams to reprogram the 32KB ISP Flash through a standard header, and 2KB SRAM buffers Modbus frames comfortably in typical panel firmware.
推薦
Battery-Powered Portable Instruments
Handheld measurement instruments need an MCU that sips current between measurements yet drives an informative display. The ATMEGA3290A-AU drives up to 160 LCD segments directly, and when sleep current is the overriding concern the pin-compatible ATMEGA3290P picoPower variant drops standby consumption dramatically with identical code compatibility. The internal oscillator option removes the crystal and its startup energy for cost- and power-sensitive designs. The 1KB EEPROM retains user calibration in the field, and the 20 MHz full-speed rating permits burst processing of ADC samples, then return to low-power idle. Designers should validate the exact voltage range and sleep figures against the datasheet for the selected variant.
推薦
Building Automation Keypads and Thermostats
Room controllers and programmable thermostats pair a segmented LCD with buttons and actuator outputs. The ATMEGA3290A-AU covers this exactly: the on-chip LCD controller shows temperature, setpoint, and schedule icons at 4x40 segment scale with internal contrast control across ambient conditions, while 69 I/O lines handle the button matrix, triac or relay drive, and damper motor feedback. Two 8-bit timers generate PWM outputs for actuator positioning, and the 16-bit timer timestamps occupancy events. The 32KB Flash accommodates schedules, PID loops, and communication stacks with read-while-write support allowing schedule storage in program Flash. JTAG programming simplifies OEM configuration at the assembly line.
推薦
POS and Vending Machine Displays
Vending machines, ticket terminals, and price displays need rugged segmented displays plus plentiful I/O for coin acceptors, motors, and sensors. The ATMEGA3290A-AU drives 160 LCD segments natively with internal contrast control that compensates for outdoor temperature swings, and its 69 GPIO lines directly manage mdb-style peripheral signaling, door switches, and motor H-bridge enables. The industrial temperature rating suits unheated kiosk enclosures, and the 1KB EEPROM logs transaction counters across power loss. Firmware stored in 32KB read-while-write Flash can be updated in service via JTAG. Where more program space is needed, the pin-compatible ATMEGA6490A doubles Flash without a PCB change.
推薦
Automotive and White-Goods Cluster Displays
Appliance control boards and basic vehicle cluster segments benefit from a single-chip solution that combines the LCD driver, timers, and EEPROM. The ATMEGA3290A-AU renders speed, temperature, and cycle-status segments through its 4x40 LCD controller, while timers drive buzzer tones and button backlight PWM. The 1KB EEPROM persists user cycle preferences, and the industrial temperature range supports under-hood-adjacent or kitchen environments. Engineers should evaluate the ATMEGA3290PA picoPower variant when standby current regulations (e.g., appliance off-mode limits) apply, since it is pin- and code-compatible. JTAG boundary-scan assists manufacturing test of the dense TQFP-100 solder joints on the cluster PCB.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA3290A-AU — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ATMEGA3290P-AU | ATMEGA6490A-AU | ATMEGA6450A-AU | ATMEGA3250V-8AUR |
|---|---|---|---|---|---|
| Package | 100-TQFP (14x14 mm) | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 32KB | 32KB | 64KB | 64KB | 32KB |
| LCD Controller | Yes, 4x40 segments | Yes, 4x40 segments | Yes | No | No |
| Low-Power Feature | Standard AVR sleep modes | picoPower | Standard | Standard | Low-voltage 1.8V operation |
| JTAG Debug | Yes | Yes | Yes | Yes | Yes |
主要差異化特點
- Integrated 4x40 segment LCD controller with internal contrast control (對比ATMEGA6450A-AU)
- Standard power variant at lower cost than picoPower (對比ATMEGA3290P-AU)
- 20 MHz full-speed operation (對比ATMEGA3250V-8AUR)
設計說明
The 100-TQFP (14x14 mm) land pattern requires 0.5 mm pitch stencil design; use a 1:1 aperture with nano-coated stencils to avoid bridging on the fine-pitch perimeter. Route JTAG (TCK, TMS, TDI, TDO) to a 2x5 header near the MCU for production programming and debug, and keep LCD segment traces short and away from switching traces to prevent ghosting on the glass. Add 100 nF decoupling at each VCC/AVCC pin pair.
Decouple AVCC separately from VCC with an LC or RC filter (e.g., 10 uH ferrite plus 100 nF) since AVCC also supplies the ADC and LCD driver - ripple on AVCC appears as LCD contrast variation. If battery operation matters, evaluate the pin-compatible ATMEGA3290P/PA picoPower variants whose sleep current is orders of magnitude lower; they are code-compatible so the swap is a sourcing decision, not a redesign. Verify the exact operating voltage range in the datasheet for your speed grade.
Do not confuse the AU (tray) and AUR (Tape & Reel) suffixes when ordering for automated assembly - both are identical die but packaging differs. Remember JTAG can be fused off to free four port pins; if JTAG pins behave unexpectedly as GPIO, check fuse settings. The 'A' versus 'P' suffix is not cosmetic: sleep current differs substantially between ATMEGA3290A and ATMEGA3290P, so lock the correct variant in the BOM early.
合規資訊
Distributor listings (Mouser/FindIC) describe the part as GRN (Green) package, industrial temperature range. Formal RoHS/REACH certificates should be pulled from Microchip's product page for your build.
