ATMEGA164P-15AT - 16MHz AVR MCU 16KB Flash 44-TQFP | Microchip
MPN: ATMEGA164P-15AT β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.6 | $3.60 |
| 10 | $3.24 | $32.40 |
| 100 | $2.88 | $288.00 |
| 500 | $2.61 | $1,305.00 |
| 1,000 | $2.35 | $2,350.00 |
ATMEGA164P-15AT Overview
An 8-bit AVR microcontroller is a single-chip computing device built around the AVR enhanced RISC architecture, which executes most of its 131 powerful instructions in a single clock cycle. Within the system hierarchy, an MCU such as the ATmega164P integrates processor core, program memory, data memory, timers, communication peripherals, and an ADC into one package, making it the heart of embedded control systems where a discrete CPU plus external memory would otherwise be required.
Key differentiating features include read-while-write FLASH for safe in-application firmware updates, the picoPower technology suite for sub-microamp power-down current, three flexible 16-bit and 8-bit timer/counters with compare modes and PWM, and two full USARTs. Per the Microchip product page, the device also provides a byte-oriented Two-Wire (I2C) interface, an 8-channel 10-bit ADC, and an on-chip internal oscillator, reducing external component count.
The ATMEGA164P-15AT operates from 2.7V to 5.5V with a 16 MHz maximum clock. The picoPower variant's internal voltage regulator and low-power design modes (idle, power-down, power-save, standby) enable battery-powered designs with multi-year battery life. The AVR core's 32 general-purpose working registers are directly connected to the ALU, allowing two independent registers to be accessed in one instruction and delivering up to 16 MIPS throughput at 16 MHz.
Typical applications include industrial automation and control nodes, home and building automation, battery-powered portable instruments, and sensor interfaces exploiting the 10-bit ADC. Two USARTs simplify multi-drop communication systems and RS-485 gateways.
When designing with this MCU, budget the 1 KB SRAM carefully; large buffers or deep stacks in C code can overflow quickly, so static allocation review is essential at this memory class.
This page synthesizes distributor data, drop-in family alternatives, pinout, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA164P-15AT β 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 ATMEGA164P-15AT (same form factor and footprint) β differing in EEPROM, ADC, Core, Core Architecture, Instructions.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA164A-MU
β Drop-Inβ In Stock
$3.01 / Unit
View Datasheet βATMEGA324P-15AT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA644P-15AT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164PA-15AT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1284P-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
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View Datasheet βATMEGA164P-15AT Maximum Ratings & Electrical Characteristics
| Core | 8-bit AVR RISC |
| Program Memory Size | 16 KB (8K x 16) FLASH |
| RAM Size | 1K x 8 SRAM |
| EEPROM | 512 B |
| Number of I/O | 32 |
| Maximum Clock Speed | 16 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| ADC Resolution | 10-bit |
| ADC Channels | 8-channel |
| Communication Interfaces | I2C (Two-Wire), SPI, 2x UART/USART |
| Timers/Counters | 3 (with compare modes and PWM) |
| Oscillator Type | Internal |
| Package / Case | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Program Features | High-performance, low-power AVR 8-bit RISC, 131 instructions, 32 general-purpose working registers |
| Series | AVR ATmega, picoPower |
ATMEGA164P-15AT Pin Configuration
| Pin 1 | PB5 (MOSI) β Port B bit 5 / SPI Master Output Slave Input |
| Pin 2 | PB6 (MISO) β Port B bit 6 / SPI Master Input Slave Output |
| Pin 3 | PB7 (SCK) β Port B bit 7 / SPI Serial Clock |
| Pin 4 | RESET β Active-low reset input |
| Pin 5 | VCC β Digital supply voltage (2.7V to 5.5V) |
| Pin 6 | GND β Ground |
| Pin 7 | XTAL2 β Inverting oscillator amplifier output / internal clock output |
| Pin 8 | XTAL1 β Inverting oscillator amplifier input / external clock input |
| Pin 9 | PA0 (ADC0) β Port A bit 0 / ADC channel 0 |
| Pin 10 | PA1 (ADC1) β Port A bit 1 / ADC channel 1 |
| Pin 11 | PA2 (ADC2) β Port A bit 2 / ADC channel 2 |
| Pin 12 | PA3 (ADC3) β Port A bit 3 / ADC channel 3 |
| Pin 13 | PA4 (ADC4) β Port A bit 4 / ADC channel 4 |
| Pin 14 | PA5 (ADC5) β Port A bit 5 / ADC channel 5 |
| Pin 15 | PA6 (ADC6) β Port A bit 6 / ADC channel 6 |
| Pin 16 | PA7 (ADC7) β Port A bit 7 / ADC channel 7 |
| Pin 17 | PE0 (RXD0) β Port E bit 0 / USART0 receive |
| Pin 18 | PE1 (TXD0) β Port E bit 1 / USART0 transmit |
| Pin 19 | PE2 (XCK0/AIN0) β Port E bit 2 / USART0 external clock / analog comparator 0 positive |
| Pin 20 | PE3 (AIN1) β Port E bit 3 / analog comparator 1 negative |
| Pin 21 | PC0 (SCL) β Port C bit 0 / Two-Wire interface clock |
| Pin 22 | PC1 (SDA) β Port C bit 1 / Two-Wire interface data |
| Pin 23 | PC2 (TCK) β Port C bit 2 / JTAG test clock |
| Pin 24 | PC3 (TMS) β Port C bit 3 / JTAG test mode select |
| Pin 25 | PC4 (TDO) β Port C bit 4 / JTAG test data output |
| Pin 26 | PC5 (TDI) β Port C bit 5 / JTAG test data input |
| Pin 27 | PC6 (TOSC1) β Port C bit 6 / Timer oscillator input |
| Pin 28 | PC7 (TOSC2) β Port C bit 7 / Timer oscillator output |
| Pin 29 | AVCC β ADC analog supply voltage |
| Pin 30 | AREF β Analog reference for ADC |
| Pin 31 | GND β Ground |
| Pin 32 | PD0 (RXD1) β Port D bit 0 / USART1 receive |
| Pin 33 | PD1 (TXD1) β Port D bit 1 / USART1 transmit |
| Pin 34 | PD2 (XCK1) β Port D bit 2 / USART1 external clock |
| Pin 35 | PD3 (OC2B) β Port D bit 3 / Timer2 output compare B |
| Pin 36 | PD4 (OC1A) β Port D bit 4 / Timer1 output compare A |
| Pin 37 | PD5 (OC1B) β Port D bit 5 / Timer1 output compare B |
| Pin 38 | PD6 (OC2A) β Port D bit 6 / Timer2 output compare A |
| Pin 39 | PD7 (OC0A) β Port D bit 7 / Timer0 output compare A |
| Pin 40 | PB0 (SS) β Port B bit 0 / SPI Slave Select |
| Pin 41 | PB1 (OC1A) β Port B bit 1 / Timer1 output compare A (alternate) |
| Pin 42 | PB2 (OC1B) β Port B bit 2 / Timer1 output compare B (alternate) |
| Pin 43 | PB3 (OC0A) β Port B bit 3 / Timer0 output compare A (alternate) |
| Pin 44 | PB4 (OC0B) β Port B bit 4 / Timer0 output compare B |
Typical Applications
ATMEGA164P-15AT is suitable for 6 applications: Industrial Automation and Control, Battery-Powered Portable Instruments, Home and Building Automation, Sensor Interfaces and Data Acquisition, Communication and Multi-Drop Systems, Motor Control and PWM Systems.
Industrial Automation and Control
The ATMEGA164P-15AT fits industrial control nodes because it combines a 16 MHz AVR core with 32 GPIO lines, two USARTs, and an 8-channel 10-bit ADC, allowing a single chip to read sensors, drive relays through PWM, and communicate on RS-485 or Modbus-style buses. Operating from a 5V industrial supply within its 2.7V to 5.5V range, it sustains full-speed operation with watchdog protection for fail-safe behavior. Typical circuits use one USART bridged to an RS-485 transceiver with the second USART reserved for diagnostics, while the EEPROM stores calibration and device-address data across power cycles. The 44-TQFP surface-mount package suits automated assembly of control boards.
Recommended
Battery-Powered Portable Instruments
picoPower technology makes the ATMEGA164P-15AT well suited to battery products: multiple sleep modes (idle, power-down, power-save, standby) let the device sleep in the microamp range between measurements, waking on pin-change or asynchronous timer events. At the 2.7V lower supply limit the internal oscillator eliminates the crystal, removing a leakage and cost element. A portable meter typically samples with the 10-bit ADC at low duty cycle, stores results in the 1 KB SRAM, and reports over USART; multi-year coin-cell or AA battery life is achievable when the duty cycle is below a few percent. Designers should profile sleep-mode currents per the datasheet power-management chapter.
Recommended
Home and Building Automation
The byte-oriented Two-Wire (I2C) interface, 32 I/O lines, and 512 B EEPROM of the ATMEGA164P-15AT map directly onto home-automation node requirements: I2C connects RTCs, temperature sensors, and EEPROM expansions, while abundant GPIO drives keypads, LEDs, and relay banks. Two USARTs allow simultaneous DALI/DMX or PLC-modem and debug links. The picoPower profile suits wall-powered-but-always-on devices where standby energy budgets are regulated. Boards benefit from the 10x10 mm 44-TQFP footprint, and the read-while-write FLASH supports field firmware updates over the serial link without stopping sensor polling, an important availability feature in installed automation products.
Recommended
Sensor Interfaces and Data Acquisition
With an 8-channel 10-bit ADC and internal reference options, the ATMEGA164P-15AT can digitize up to eight analog sensor inputs without external converters, making it a compact front-end for temperature, pressure, and potentiometer arrays. The AVR core processes scaling and averaging in firmware at up to 16 MIPS, and the SPI interface streams results to external flash or a host controller at multi-MHz rates. The 1 KB SRAM supports modest buffering blocks, and the EEPROM retains calibration constants. For precision channels, a filtered external reference on the AREF pin improves absolute accuracy versus the internal bandgap, per the datasheet analog chapter.
Recommended
Communication and Multi-Drop Systems
Two full-duplex USARTs distinguish the ATMEGA164P-15AT from smaller AVRs and suit multi-drop communication equipment: one USART serves a Modbus/RS-485 field bus while the second handles a local HMI or logging port. The SPI master handles Ethernet-adjacent encoders or radio modules, and hardware-polled interrupt-driven serial service keeps latency deterministic at 16 MHz. Because the device integrates everything in a 44-TQFP, gateway cards can shrink to a few square centimeters. Firmware should implement circular buffers for both UARTs within the 1 KB SRAM budget, and the byte-level Two-Wire interface links configuration EEPROMs and real-time clocks on the same two-wire bus.
Recommended
Motor Control and PWM Systems
Three timer/counters with compare modes and PWM outputs let the ATMEGA164P-15AT generate multi-channel PWM for DC motor speed control, servo positioning, and LED dimming. A typical loop reads an encoder or potentiometer through the 10-bit ADC, executes a PID routine on the 16 MHz core, and updates an 8-bit or 16-bit PWM duty cycle in hardware, ensuring glitch-free edges independent of software jitter. Dead-time for H-bridge drive can be implemented in firmware using timer compare interrupts. The 2.7V to 5.5V supply range allows direct interfacing with standard 5V gate drivers, simplifying the power stage design around this MCU.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164P-15AT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164A-MU | ATMEGA324P-15AT | ATMEGA644P-15AT | ATMEGA1284P-MUR |
|---|---|---|---|---|---|
| Package | 44-TQFP (10x10) | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| FLASH Memory | 16 KB | 16 KB | 32 KB | 64 KB | 128 KB |
| SRAM | 1 KB | 1 KB | 2 KB | 4 KB | 16 KB |
| EEPROM | 512 B | 512 B | 1 KB | 2 KB | 4 KB |
| Maximum Clock Speed | 16 MHz | 16 MHz (20 MHz for -A grade) | 16 MHz | 16 MHz | 16 MHz |
| GPIO Count | 32 | 32 | 32 | 32 | 32 |
| Supply Voltage | 2.7 V to 5.5 V | 1.8 V to 5.5 V (V grade) | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V |
| ADC | 8-ch 10-bit | 8-ch 10-bit | 8-ch 10-bit | 8-ch 10-bit | 8-ch 10-bit |
| Relative Unit Price | Baseline (as of 2026-09-16) | Comparable | Slightly higher | Higher | Highest |
Key Differentiators
- Two full USARTs instead of one (vs ATMEGA164A-MU)
- Lowest-cost entry to the 44-TQFP ATmega family (vs ATMEGA324P-15AT)
- 16 KB is the practical ceiling (vs ATMEGA644P-15AT)
Design Notes
Decouple VCC (pin 5) and AVCC (pin 29) separately: place a 100 nF ceramic capacitor within 5 mm of each pin plus a 10 uF bulk capacitor per board. AVCC must be connected to VCC even when the ADC is unused, through a low-pass RC (e.g., 10 ohm / 100 nF) for clean analog performance. Ensure AVCC never exceeds VCC by more than 0.3 V per the datasheet absolute maximum ratings, and sequence power-up so AVCC and VCC rise together.
In the 44-TQFP (10x10 mm), use the center pad-free standard footprint with 0.5 mm pitch; fan out Port A ADC traces away from the two USART lines and SPI clock to minimize digital coupling into analog channels. Route the AREF pin with a short trace and its own 100 nF capacitor to ground; never connect a capacitor directly to AREF if the internal reference is selected without checking the datasheet guidance. Provide an unbroken ground plane under the MCU; avoid routing high-current PWM returns under Port A.
The 1 KB SRAM fills quickly: in AVR-GCC, default stack grows downward from RAMEND, and heap fragmentation or large local arrays cause silent overwrites. Use -Wl,--print-gc-sections and stack-usage checks, and reserve at least 20% SRAM headroom. Also note the speed-voltage derating: 16 MHz operation is not guaranteed at 3.3V per the frequency-voltage curve; a 3.3V system should clock at 13 MHz or lower (8 MHz internal oscillator is the safe choice) to stay within the datasheet safe operating region.
RESET (pin 4) needs a 10 kohm pull-up and optionally a 100 nF to ground for robust power-on reset with external programmers. JTAG enable (fuse) reassigns PC2-PC5 at reset; if the application uses those pins as GPIO, disable JTAGEN in fuses, otherwise output states will not hold. For ISP programming, keep series resistors on MOSI/MISO/SCK small (under 1 kohm) and ensure slave devices do not drive these lines during programming.
Compliance Information
RoHS-compliant lead-free 44-TQFP per standard Microchip AVR product offering; explicit RoHS/REACH certificate text for this exact ordering code not present in supplied web data - verify on the Microchip product page.
