ATMEGA324PB-AN - 8-Bit AVR MCU 20MHz 32KB Flash | Microchip
MPN: ATMEGA324PB-AN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.4 | $2.40 |
| 10 | $2.28 | $22.80 |
| 100 | $2.1 | $210.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.82 | $1,820.00 |
ATMEGA324PB-AN Overview
A microcontroller unit (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals on one die. The AVR ATmega family sits within the broader microcontroller hierarchy: AVR RISC core -> 8-bit MCU -> embedded processor -> semiconductor IC. MCUs execute control, sensing, and communication tasks in embedded systems ranging from appliances to industrial automation.
The ATMEGA324PB-AN combines 32 KB (16K x 16) flash with read-while-write capability, 1 KB EEPROM, and 2 KB SRAM. Its AVR RISC architecture executes most instructions in a single clock cycle, achieving up to 20 MIPS throughput at 20 MHz. The PB variant adds five flexible timer/counters, enhanced connectivity (I2C, SPI, UART/USART with additional instances), brown-out detect/reset, power-on reset, PWM, and a watchdog timer compared to earlier ATmega324 derivatives.
A distinguishing feature is the integrated Peripheral Touch Controller (PTC), supported by Microchip QTouch Composer and the QTouch Library. The ATmega324PB supports 32 buttons in self-capacitance mode or up to 256 buttons in mutual-capacitance mode, with mix-and-match sensor configurations and no external components per electrode, reducing BOM cost versus competing touch solutions.
Typical applications include capacitive touch HMI panels, industrial control and automation nodes, consumer appliances, and embedded systems leveraging the picoPower technology for low-power battery-operated designs operating at 5 V.
For design, the 44-TQFP 10x10 mm footprint requires careful decoupling (100 nF ceramic per VCC pin placed close to the supply pins) and consideration of the brown-out threshold when using the internal reset supervisor.
This page synthesizes distributor pricing, drop-in alternative cross-references, and practical design guidance not found in the manufacturer datasheet, giving engineers a single citable reference for the ATMEGA324PB-AN.
Drop-in alternatives for ATMEGA324PB-AN — 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 ATMEGA324PB-AN (same form factor and footprint) — differing in Package, Program Memory Size, Serial Interfaces, Timer/Counters, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA324PB-AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA324PA-AUR
✅ Drop-In✓ In Stock
$1.98 / Unit
View Datasheet →ATMEGA324A-AU
✅ Drop-In✓ In Stock
$2.09 / Unit
View Datasheet →ATMEGA324P-20AUR
✅ Drop-In✓ In Stock
$4.52 / Unit
View Datasheet →ATMEGA32-16AUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.41 / Unit
View Datasheet →ATMEGA324PB-AN Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Max Clock Speed | 20 MHz |
| Program Memory Size | 32 KB (16K x 16) |
| Program Memory Type | FLASH |
| EEPROM Size | 1 KB |
| SRAM Size | 2 KB |
| Number of I/O | 39 |
| General Purpose Working Registers | 32 |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT, PTC |
| Timer/Counters | 5 |
| Supply Voltage | 5 V |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Series | AVR ATmega, Functional Safety (FuSa) |
| RoHS Status | Green / compliant |
ATMEGA324PB-AN 44-tqfp (10x10 mm) Pin Configuration Guide
Pin configuration for ATMEGA324PB-AN (44-tqfp (10x10 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 ATMEGA324PB-AN.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA324PB-AN is suitable for 6 applications: Capacitive Touch HMI Panels, Industrial Control and Automation, Consumer Appliances, Battery-Powered Embedded Devices, Sensor Acquisition Nodes, Educational and Hobbyist Embedded Platforms.
Capacitive Touch HMI Panels
The ATMEGA324PB-AN's integrated Peripheral Touch Controller makes it a natural fit for touch-based human-machine interfaces. The PTC supports 32 self-capacitance buttons or up to 256 mutual-capacitance buttons with only one pin per electrode and no external components, directly reducing BOM cost compared to discrete touch controller solutions. Development is streamlined by Microchip QTouch Composer, which includes the QTouch Library project builder and QTouch Analyzer for tuning sensitivity and drift compensation. In a typical panel, the MCU runs touch scanning in the background while the five timer/counters drive backlight PWM and buzzer feedback, and the USART reports touch events to a host controller at 5 V logic levels.
Recommended
Industrial Control and Automation
In factory automation nodes, the ATMEGA324PB-AN provides 39 GPIO lines, five timer/counters, and I2C, SPI, and UART/USART connectivity in one 44-TQFP device, allowing sensor acquisition, actuator PWM control, and Modbus-style UART communication on a single chip. The brown-out detect/reset, power-on reset, and watchdog timer peripherals deliver the supervision needed for unattended industrial environments, while the part's Functional Safety (FuSa) designation supports safety documentation requirements. At 20 MHz the AVR RISC core yields up to 20 MIPS, sufficient for closed-loop control at kilohertz rates. Operating at 5 V provides robust noise margins against industrial EMI on long cable runs to sensors and relays.
Recommended
Consumer Appliances
Home appliances such as washing machines, ovens, and coffee makers benefit from the ATMEGA324PB-AN's combination of touch input (via the PTC), PWM outputs for motor and heater control, and 1 KB EEPROM for storing user settings and cycle counters across power cycles. The picoPower technology reduces standby consumption, relevant to appliance energy regulations. With 32 KB of flash and read-while-write capability, firmware can log usage data to flash during operation. The 44-pin TQFP offers enough GPIO for segment LCD driving via software, relay outputs, and multiple sensor inputs in a single cost-effective 8-bit controller operating from a 5 V supply.
Recommended
Battery-Powered Embedded Devices
The ATmega324PB's picoPower technology makes the ATMEGA324PB-AN suitable for battery-operated products such as meters, remote controls, and portable instruments. Power-down and power-save sleep modes, combined with the watchdog timer and asynchronous timer clock sources (TOSC1/TOSC2 pins), allow periodic wake-up from deep sleep at microamp-level standby currents. The extended temperature suffix supports outdoor and automotive-adjacent environments. Designers should budget the 5 V supply rail or use a step-up regulator for single-cell operation, and can exploit the 32 general-purpose working registers for efficient interrupt service routines that minimize active-mode time and extend battery life.
Recommended
Sensor Acquisition Nodes
With 39 GPIO, SPI, I2C, and multiple USARTs, the ATMEGA324PB-AN aggregates data from digital sensors (temperature, pressure, accelerometers) over I2C and SPI while bit-banging or hardware-scanning additional analog inputs through the AVR's ADC-multiplexed port pins. The five timer/counters enable precise sensor sampling intervals and input-capture measurements of external pulse streams such as flow meters. Data is forwarded over UART to a gateway or logged into the 2 KB SRAM ring buffer for batch transmission. The part's 20 MHz throughput provides ample headroom for protocol stacking (e.g., CRC-checked framing) while servicing multiple sensor buses concurrently at 5 V logic levels.
Recommended
Educational and Hobbyist Embedded Platforms
The ATmega324 family is a popular teaching platform because it exposes classic 8-bit MCU concepts - ports, timers, interrupts, UART - without complex clock trees. The ATMEGA324PB-AN is supported by the open-source MightyCore Arduino hardware package on GitHub, alongside ATmega1284, ATmega644, ATmega324, ATmega164, ATmega32, ATmega16, and ATmega8535, enabling Arduino IDE development with standard ISP programmers. Its 32 KB flash and 2 KB SRAM accommodate non-trivial coursework projects, while the 44-TQFP package can be hand-soldered on adapter boards. Low single-unit pricing around $2.40 as of 2026-09-17 keeps per-student kit costs minimal.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA324PB-AN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA324PB-AU | ATMEGA324PA-AU | ATMEGA324A-AU | ATMEGA32-16AUR |
|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 16 MHz |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| GPIO Count | 39 | 39 | 36 | 36 | 32 |
| Touch Controller (PTC) | Yes (32 self-cap / 256 mutual-cap buttons) | Yes (32 self-cap / 256 mutual-cap buttons) | No | No | No |
Key Differentiators
- Integrated Peripheral Touch Controller (vs ATMEGA324PA-AU)
- Highest peripheral count in the ATmega324 family (vs ATMEGA324A-AU)
- Functional Safety (FuSa) documentation support (vs ATMEGA32-16AUR)
- Trade-off: newer silicon requires porting validation (vs ATMEGA324P-20AU)
Design Notes
Decouple each VCC pin with a 100 nF ceramic capacitor placed within a few millimeters of the pin, plus one bulk 10 uF capacitor near the supply entry. The AVR core draws supply current spikes on every clock edge; inadequate decoupling causes brown-out resets that are often misdiagnosed as firmware bugs. Configure the brown-out detector level appropriate to the 5 V rail and enable the watchdog timer (WDT) in production firmware so a latch-up or runaway loop triggers a controlled reset rather than a field failure.
The 44-TQFP (10x10 mm) lead pitch of 0.8 mm is hand-solderable with drag soldering, but for production use a solder-mask-defined land pattern per the Microchip mechanical drawing. Keep the XTAL1/XTAL2 crystal traces short and guard them with ground pour to avoid oscillator start-up problems, especially when using a low-drive crystal. Route the PTC touch electrode traces away from switching signals; touch sense lines adjacent to PWM or SPI traces can inject enough coupled noise to cause false key detections.
Do not assume firmware written for ATMEGA324P/PA runs unchanged on the PB: the PB silicon has extra peripherals and some register and signature-row differences, so verify the device signature when programming and re-check timer/USART register maps when porting. Conversely, PB binaries will not run on PA silicon. When second-sourcing within the family, remember that only the PB variant provides the PTC touch controller - dropping to ATMEGA324PA-AU for cost savings silently removes touch capability.
Compliance Information
Mouser listing describes the part as 'GREEN 5 V', indicating Microchip green/RoHS-compliant packaging. Full REACH, halogen-free, and conflict-minerals status should be confirmed from the official Microchip product page.