ATMEGA163-8AI - 8-bit AVR MCU 16KB Flash 8MHz TQFP-44 | Microchip
MPN: ATMEGA163-8AI β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $5.85 | $58.50 |
| 100 | $5.2 | $520.00 |
| 500 | $4.68 | $2,340.00 |
| 1,000 | $4.22 | $4,220.00 |
ATMEGA163-8AI Overview
An ATmega microcontroller is a member of the AVR family of 8-bit RISC microcontrollers, which sit within the broader hierarchy of embedded microcontroller units (MCUs) under semiconductor integrated circuits. AVR cores execute most instructions in a single clock cycle using a Harvard architecture with separate program and data buses, delivering roughly 1 MIPS per MHz of clock speed. This makes AVR MCUs a popular choice for embedded control where deterministic, code-dense execution matters.
Key features of the ATMEGA163-8AI include 16KB self-programmable Flash, 512B EEPROM, 1KB internal SRAM, and a rich peripheral set: a 10-bit ADC, two 8-bit timers, one 16-bit timer, and I2C (TWI), SPI, and UART/USART serial interfaces. The 8-bit AVR RISC core with 32 general-purpose registers enables efficient C compiler output. The 'A' grade and 'I' suffix denote an industrial temperature range of -40C to +85C, and the device operates from a 5V supply (4.5V to 5.5V for the 8MHz speed grade).
Technically, the device uses In-System Programming (ISP) via the SPI port, allowing firmware updates on the assembled PCB without removing the chip. Multiple power-saving idle and power-down modes reduce current consumption in battery-aware designs.
Typical applications include industrial control panels, sensor and instrumentation nodes, and legacy consumer/appliance boards where a 5V AVR with ISP Flash is required.
Design consideration: the ATmega163 is a legacy device; new designs should evaluate the pin-compatible ATmega16 or ATmega162 family, which offer higher performance in the same TQFP-44 footprint.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA163-8AI 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 ATMEGA163-8AI (same form factor and footprint) β differing in Operating Temperature, Package, Mounting Type, Core Architecture, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA16-16AU
β Drop-Inβ In Stock
$4.41 / Unit
View Datasheet βATMEGA162-16AU
β Drop-Inβ In Stock
$2.45 / Unit
View Datasheet βATMEGA161-16AI
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA32-16AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA162V-8AUR
β Drop-Inβ In Stock
$6.62 / Unit
View Datasheet βATMEGA328PB-AUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA163-8AI Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 8 MHz |
| Flash Program Memory | 16KB (8K x 16) |
| SRAM | 1KB |
| Supply Voltage | 4.5 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | 10-bit ADC, PWM, WDT |
| Program Memory Type | In-System Programmable FLASH |
| Architecture | Harvard RISC, single-cycle instructions |
ATMEGA163-8AI Pin Configuration
| Pin 1 | PA3 (ADC3) β Port A, bit 3 / ADC channel 3 |
| Pin 2 | PA2 (ADC2) β Port A, bit 2 / ADC channel 2 |
| Pin 3 | PA1 (ADC1) β Port A, bit 1 / ADC channel 1 |
| Pin 4 | PA0 (ADC0) β Port A, bit 0 / ADC channel 0 |
| Pin 5 | VCC β Digital supply voltage |
| Pin 6 | GND β Ground |
| Pin 7 | PB0 (XCK/T0) β Port B, bit 0 / USART external clock / Timer0 clock input |
| Pin 8 | PB1 (T1) β Port B, bit 1 / Timer1 external counter input |
| Pin 9 | PB2 (AIN0/INT2) β Port B, bit 2 / analog comparator positive input / external interrupt 2 |
| Pin 10 | PB3 (AIN1/OC0) β Port B, bit 3 / analog comparator negative input / Timer0 output compare PWM |
| Pin 11 | PB4 (SS) β Port B, bit 4 / SPI slave select |
| Pin 12 | PB5 (MOSI) β Port B, bit 5 / SPI master output slave input (ISP data in) |
| Pin 13 | PB6 (MISO) β Port B, bit 6 / SPI master input slave output (ISP data out) |
| Pin 14 | PB7 (SCK) β Port B, bit 7 / SPI serial clock (ISP clock) |
| Pin 15 | RESET β Reset input, active low; also used for ISP programming |
| Pin 16 | VCC β Digital supply voltage |
| Pin 17 | GND β Ground |
| Pin 18 | XTAL2 β Inverting oscillator amplifier output |
| Pin 19 | XTAL1 β Inverting oscillator amplifier input / external clock input |
| Pin 20 | PD0 (RXD) β Port D, bit 0 / USART receive data |
| Pin 21 | PD1 (TXD) β Port D, bit 1 / USART transmit data |
| Pin 22 | PD2 (INT0) β Port D, bit 2 / external interrupt 0 |
| Pin 23 | PD3 (INT1) β Port D, bit 3 / external interrupt 1 |
| Pin 24 | PD4 (OC1B) β Port D, bit 4 / Timer1 output compare B PWM output |
| Pin 25 | PD5 (OC1A) β Port D, bit 5 / Timer1 output compare A PWM output |
| Pin 26 | PD6 (ICP1) β Port D, bit 6 / Timer1 input capture |
| Pin 27 | PD7 (OC2) β Port D, bit 7 / Timer2 output compare PWM output |
| Pin 28 | AREF β ADC reference voltage |
| Pin 29 | AGND β Analog ground |
| Pin 30 | AVCC β ADC supply voltage |
| Pin 31 | PC0 (SCL) β Port C, bit 0 / TWI (I2C) serial clock |
| Pin 32 | PC1 (SDA) β Port C, bit 1 / TWI (I2C) serial data |
| Pin 33 | PC2 (TCK) β Port C, bit 2 / JTAG test clock (on successors) |
| Pin 34 | PC3 (TMS) β Port C, bit 3 / JTAG test mode select (on successors) |
| Pin 35 | PC4 (TDO) β Port C, bit 4 / JTAG test data output (on successors) |
| Pin 36 | PC5 (TDI) β Port C, bit 5 / JTAG test data input (on successors) |
| Pin 37 | PC6 (TOSC1) β Port C, bit 6 / timer oscillator input (on successors) |
| Pin 38 | PC7 (TOSC2) β Port C, bit 7 / timer oscillator output (on successors) |
| Pin 39 | PA7 (ADC7) β Port A, bit 7 / ADC channel 7 |
| Pin 40 | PA6 (ADC6) β Port A, bit 6 / ADC channel 6 |
| Pin 41 | PA5 (ADC5) β Port A, bit 5 / ADC channel 5 |
| Pin 42 | PA4 (ADC4) β Port A, bit 4 / ADC channel 4 |
| Pin 43 | GND β Ground |
| Pin 44 | VCC β Digital supply voltage |
Typical Applications
ATMEGA163-8AI is suitable for 6 applications: Industrial Control Panels, Sensor and Instrumentation Nodes, Legacy Appliance and Consumer Board Maintenance, Motor Control and PWM Load Drivers, Embedded Communication Interfaces, Battery-Powered and Low-Power Data Loggers.
Industrial Control Panels
The ATMEGA163-8AI fits industrial control panels where 5V logic, strong I/O noise immunity, and proven legacy firmware are required. Its industrial -40C to +85C temperature grade and TQFP-44 package with 32 general-purpose I/O lines let it drive relays, read limit switches, and handle status LEDs without external line drivers. The 16KB ISP Flash stores control state machines while the 1KB SRAM buffers sensor history, and the UART links panels to SCADA gateways. With the watchdog timer enabled, the controller recovers from brownouts and EMI-induced stalls common on factory floors. Designers should route RESET and crystal traces short and guard the 10-bit ADC reference against switching noise.
Recommended
Sensor and Instrumentation Nodes
The ATMEGA163-8AI is well suited to sensor and instrumentation nodes because its integrated 10-bit ADC digitizes transducer outputs directly at 5V full-scale, eliminating an external ADC in moderate-accuracy systems. The SPI and I2C (TWI) interfaces connect external precision ADCs, EEPROMs, and digital sensors, while the UART streams readings to a host. At 8MHz the AVR core delivers roughly 8 MIPS, sufficient for filtering and linearization math on sampled channels. Power-down and idle modes cut current between conversion cycles in intermittently powered installations. The 16KB Flash comfortably holds lookup tables and compensation code; placing a 0.1uF bypass on AVCC and using AREF with external filtering preserves conversion accuracy.
Recommended
Legacy Appliance and Consumer Board Maintenance
For repairing and continuing production of legacy appliance and consumer boards designed around the ATmega163, the ATMEGA163-8AI preserves exact footprint, pinout, and timing behavior, which minimizes requalification cost. Many 2000s-era white-goods, HVAC, and charger boards used this MCU with ISP Flash for field-updatable firmware. The 5V TQFP-44 device drives TRIAC optocouplers and 7-segment displays directly through its ports, and its 8MHz internal timing assumptions keep existing delay loops valid. When original stock runs out, ATMEGA16-16AU replaces it on the same PCB with firmware recompilation. Confirm crystal load capacitors and fuse settings when swapping silicon generations.
Recommended
Motor Control and PWM Load Drivers
The ATMEGA163-8AI supports small motor and load control through its timer PWM outputs: two 8-bit timers and one 16-bit timer generate phase-correct or fast PWM for DC motor speed control, lamp dimming, and heater duty-cycle regulation. The 16-bit timer with input capture measures tachometer periods for closed-loop speed regulation, while the 8MHz AVR core executes PI control loops at kilohertz rates. Ports sink and source enough current to drive MOSFET gate drivers directly. The industrial temperature grade suits enclosed motor-drive environments; designers should decouple AVCC from motor switching noise and place snubbers on driver stages to protect ADC channels from inductive kickback transients.
Recommended
Embedded Communication Interfaces
With native I2C (TWI), SPI, and UART/USART on-chip, the ATMEGA163-8AI serves as a protocol bridge or peripheral controller in embedded communication designs. Typical roles include SPI-to-UART gateways, I2C slave subsystems reporting to a main processor, and RS-485 field nodes when paired with a transceiver. The 16KB Flash holds compact protocol stacks such as Modbus RTU slaves, and the hardware UART with baud-rate generator covers standard industrial rates from the 8MHz clock. The SPI port also provides the In-System Programming path, simplifying field firmware updates. Engineers should verify exact register names against the ATmega163 datasheet, as some TWI bits differ from later ATmega generations.
Recommended
Battery-Powered and Low-Power Data Loggers
Although a 5V device, the ATMEGA163-8AI's power-down and idle sleep modes make it workable in battery-backed data loggers that spend most time asleep and wake on UART activity, timer overflow, or external interrupt. The 1KB SRAM stores logged samples between communication windows, and the 512B-class EEPROM retains calibration constants across power cycles. Designers gain the most efficiency by gating the ADC and analog circuitry and using the watchdog to wake from power-down at fixed intervals. Note that at 5V the AVR core draws more static power than 3.3V successors, so for strictly battery-powered new designs the ATMEGA328PB at lower voltage is the better fit; the ATmega163 remains appropriate for AC-backed loggers with battery ride-through.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA163-8AI β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA16-16AU | ATMEGA162-16AU | ATMEGA161-16AI | ATMEGA32-16AU | ATMEGA328PB-AUR |
|---|---|---|---|---|---|---|
| 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 | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Speed | 8 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 20 MHz |
| Flash Program Memory | 16KB (8K x 16) | 16KB | 16KB | 16KB | 32KB | 32KB |
| SRAM | 1KB | 1KB | 1KB + extended addressing | 1KB | 2KB | 2KB |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V (16MHz grade) | 4.5 V to 5.5 V (16MHz grade) | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V |
| JTAG Debug | No | Yes | Yes | No | Yes | No (debugWIRE via UPDI-class tools differs) |
| Lifecycle Status | EOL / legacy | Active | Active | EOL / legacy | Active | Active |
Key Differentiators
- Legacy-exact silicon for unmodified requalification (vs ATMEGA16-16AU)
- Lower maximum speed simplifies legacy delay-code compatibility (vs ATMEGA162-16AU)
- Industrial temperature grade at 5V (vs ATMEGA328PB-AUR)
Design Notes
Supply the ATMEGA163-8AI with a regulated 5V (4.5V to 5.5V) rail and place 0.1uF ceramic bypass capacitors at each VCC pin (pins 5, 16, 44) with one 4.7uF to 10uF bulk capacitor nearby. Connect AVCC (pin 30) to VCC through a small LC or RC filter (e.g., 10 ohm resistor plus 0.1uF) to keep digital noise out of the 10-bit ADC. Tie AGND (pin 29) to a quiet analog ground region. Brown-out detection should be enabled via fuse if the application writes to EEPROM, preventing corruption during supply dips.
Keep the XTAL1/XTAL2 crystal traces (pins 19/18) as short as possible and surround them with a ground guard ring; long traces invite EMI-induced clock jitter. The RESET line (pin 15) should have a 10k pull-up and be routed away from switching loads, since glitches here can corrupt ISP sessions or trigger spurious resets. Use solid ground planes under the TQFP-44 and provide thermal relief vias near the die for heat spreading, though power dissipation is modest at 5V/8MHz. Decouple the ADC reference (AREF, pin 28) with 100nF to ground.
Because the ATmega163 is EOL, lock your firmware build against register-map differences before migrating to ATMEGA16/162: the successor adds a JTAG enable fuse (JTAGEN) that, when active, takes over PC2-PC5, removing four I/O pins that were general-purpose on the ATmega163. Disable JTAGEN (or write the JTD bit twice in software) to restore full port C. Also verify TWI bit names and EEPROM write timing, which changed slightly between generations. Always recompile rather than reusing ATmega163 hex files directly on successors.
Compliance Information
Compliance status for this legacy Atmel part is not stated in the provided web data; many ATmega163 grade variants predate full lead-free conversion. Verify with Microchip or distributor certificates of conformance.
