ATMEGA168-15AD - 8-bit AVR MCU 16KB Flash 15MHz | Microchip
MPN: ATMEGA168-15AD ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.25 | $4.25 |
| 10 | $3.95 | $39.50 |
| 100 | $3.65 | $365.00 |
| 500 | $3.4 | $1,700.00 |
| 1,000 | $3.15 | $3,150.00 |
ATMEGA168-15AD Overview
An AVR microcontroller is a member of the 8-bit RISC microcontroller family that executes most instructions in a single clock cycle using 32 general-purpose working registers. Within the semiconductor taxonomy, the ATMEGA168-15AD sits in the hierarchy of 8-bit microcontroller -> AVR RISC MCU -> embedded microcontroller -> integrated circuit. The AVR architecture pairs a Harvard memory model with on-chip flash, SRAM, and EEPROM, allowing self-programming and read-while-write operation without external memory.
Key features include 16 KB ISP flash with read-while-write, 1 KB SRAM, 512 B EEPROM, 23 general-purpose I/O lines, 32 general-purpose working registers, three flexible timer/counters with compare modes, an 8-channel 10-bit ADC, a programmable watchdog timer with internal oscillator, and debugWIRE on-chip debug support. The device also integrates a byte-oriented two-wire serial interface, a master/slave SPI serial interface, and a programmable USART for serial communication.
The ATMEGA168-15AD is fabricated in high-density nonvolatile CMOS technology and supports both in-system programming and in-application programming through the SPI interface or a boot loader. Its 15 MHz maximum clock rate and 2.7 V to 5.5 V supply range allow it to bridge 3.3 V and 5 V logic domains, while the 32-pin TQFP footprint keeps board area small for space-constrained control boards.
Typical applications include automotive body control modules, industrial sensor nodes, motor control front ends, battery-powered instrumentation, and legacy AVR-based designs migrating from ATmega8 or ATmega88 platforms. The 10-bit ADC and multiple timers make it suitable for closed-loop control, while the USART and SPI interfaces support field-bus and peripheral expansion.
When designing with this device, decouple every VCC pin with a 100 nF ceramic capacitor placed close to the pin, and keep the AREF pin bypassed to ground for ADC accuracy. The 15 MHz speed grade requires careful clock-source selection and adequate supply headroom.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single reference for selection, replacement, and layout decisions.
Drop-in alternatives for ATMEGA168-15AD — 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 ATMEGA168-15AD (same form factor and footprint) — differing in Package, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA168PA-AU
✅ Drop-In✓ In Stock
$0.98 / Unit
View Datasheet →ATMEGA168V-10AU
✅ Drop-In✓ In Stock
$1.1 / Unit
View Datasheet →ATMEGA88-15AD
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA168PA-15MZ
✅ Drop-In✓ In Stock
$1.26 / Unit
View Datasheet →ATMEGA168-15AT1
✅ Drop-In✓ In Stock
$1.1 / Unit
View Datasheet →ATMEGA168-15AD Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory Size | 16 KB ISP Flash |
| Program Memory Type | Flash (read-while-write capable) |
| SRAM | 1 KB |
| EEPROM | 512 B |
| Maximum Clock Speed | 15 MHz |
| Throughput | Up to 15 MIPS at 15 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O Lines | 23 |
| General Purpose Working Registers | 32 |
| ADC | 8-channel, 10-bit |
| Timer/Counters | Three flexible timer/counters with compare modes |
| Serial Interfaces | USART, SPI (master/slave), Two-wire (I2C) |
| Debug Interface | debugWIRE on-chip debug |
| Watchdog Timer | Programmable with internal oscillator |
| Package | 32-pin TQFP (14 x 14 mm, 1 mm height) |
| Mounting Type | Surface Mount |
| Instruction Set | 133 powerful instructions, most single clock cycle |
ATMEGA168-15AD Pin Configuration
| Pin 1 | PB0 — Port B, bit 0 (also T0/XCK) |
| Pin 2 | PB1 — Port B, bit 1 (also T1) |
| Pin 3 | PB2 — Port B, bit 2 (also INT0/AIN0) |
| Pin 4 | PB3 — Port B, bit 3 (also OC0/AIN1) |
| Pin 5 | PB4 — Port B, bit 4 (also SS) |
| Pin 6 | PB5 — Port B, bit 5 (also MOSI) |
| Pin 7 | PB6 — Port B, bit 6 (also MISO) |
| Pin 8 | PB7 — Port B, bit 7 (also SCK) |
| Pin 9 | RESET — Reset input (active low) |
| Pin 10 | VCC — Digital supply voltage |
| Pin 11 | GND — Ground |
| Pin 12 | XTAL2 — Crystal oscillator output |
| Pin 13 | XTAL1 — Crystal oscillator input |
| Pin 14 | PD0 — Port D, bit 0 (also RXD) |
| Pin 15 | PD1 — Port D, bit 1 (also TXD) |
| Pin 16 | PD2 — Port D, bit 2 (also INT0) |
| Pin 17 | PD3 — Port D, bit 3 (also INT1/OC2B) |
| Pin 18 | PD4 — Port D, bit 4 (also OC0B/T0) |
| Pin 19 | PD5 — Port D, bit 5 (also OC0A/T1) |
| Pin 20 | PD6 — Port D, bit 6 (also ICP1) |
| Pin 21 | PD7 — Port D, bit 7 (also OC2A) |
| Pin 22 | PC0 — Port C, bit 0 (also ADC0) |
| Pin 23 | PC1 — Port C, bit 1 (also ADC1) |
| Pin 24 | PC2 — Port C, bit 2 (also ADC2) |
| Pin 25 | PC3 — Port C, bit 3 (also ADC3) |
| Pin 26 | PC4 — Port C, bit 4 (also ADC4) |
| Pin 27 | PC5 — Port C, bit 5 (also ADC5) |
| Pin 28 | PC6 — Port C, bit 6 (also RESET) |
| Pin 29 | PC7 — Port C, bit 7 (also ADC7) |
| Pin 30 | AVCC — Analog supply voltage for ADC |
| Pin 31 | GND — Ground |
| Pin 32 | AREF — Analog reference voltage for ADC |
Typical Applications
ATMEGA168-15AD is suitable for 6 applications: Automotive Body Control Module, Industrial Sensor Node, Motor Control Front End, Battery-Powered Instrumentation, Legacy AVR Platform Migration, Serial Communication Gateway.
Automotive Body Control Module
The ATMEGA168-15AD fits automotive body control modules because its 2.7 V to 5.5 V supply range tolerates the wide voltage swings of a 12 V automotive rail after regulation, and its 15 MHz speed grade provides enough throughput for window, mirror, and lighting control loops. The 23 general-purpose I/O lines drive relays and MOSFET gates directly, while the integrated 8-channel 10-bit ADC monitors switch inputs and potentiometer positions without external converters. In a typical BCM, the MCU runs a polling loop over the timer/counters and updates outputs through the I/O ports; the trade-off is that the 16 KB flash limits the amount of diagnostic and CAN gateway code that can be stored on-chip, so larger body controllers may need the ATmega328P or a 32-bit device.
Recommended
Industrial Sensor Node
The ATMEGA168-15AD suits industrial sensor nodes because its 8-channel 10-bit ADC digitizes bridge, thermistor, and 4-20 mA loop signals directly, and the USART plus SPI and two-wire interfaces connect to transceivers and EEPROM without glue logic. Running at 15 MHz, the core executes most instructions in a single cycle, so a 1 kHz control loop with filtering and serial reporting fits comfortably within the 16 KB flash and 1 KB SRAM budget. The device is typically clocked from an external crystal for accurate baud rates, and the watchdog timer with internal oscillator recovers the node from lockups; the trade-off is that 1 KB SRAM constrains buffer depth for high-rate data logging, so streaming to external memory is preferred over on-chip buffering.
Recommended
Motor Control Front End
The ATMEGA168-15AD works as a motor control front end because its three flexible timer/counters with compare modes generate the PWM waveforms needed for brushed DC and stepper drive, while the 10-bit ADC samples current-sense shunts for closed-loop regulation. At 15 MHz the device updates PWM duty cycles fast enough for kHz-class control loops, and the 23 I/O lines handle direction, enable, and fault signals. In a typical implementation the MCU runs a timer-driven PWM ISR and an ADC conversion ISR, with the watchdog guarding against runaway loops; the trade-off is that the 8-bit core and 16 KB flash limit advanced field-oriented control algorithms, so sensorless BLDC designs generally move to a 32-bit MCU.
Recommended
Battery-Powered Instrumentation
The ATMEGA168-15AD is well suited to battery-powered instrumentation because it operates down to 2.7 V, allowing direct connection to a single Li-ion cell or a 3 V coin cell stack, and its low-power AVR core supports idle and power-down sleep modes between measurements. The 10-bit ADC reads sensor outputs, the two-wire interface talks to an external EEPROM or display driver, and the USART streams logged data to a host. A typical design wakes the MCU on a timer interrupt, takes a burst of ADC samples, stores results, and returns to sleep; the trade-off is that the 15 MHz speed grade draws more current than the picoPower PA revision, so battery life is better served by the ATMEGA168PA-AU when maximum runtime matters.
Recommended
Legacy AVR Platform Migration
The ATMEGA168-15AD is a natural migration target for legacy ATmega8 and ATmega88 designs because it keeps the AVR instruction set and 32-pin TQFP footprint while doubling flash to 16 KB and SRAM to 1 KB. Existing firmware can often be recompiled with minimal changes, and the debugWIRE interface simplifies bring-up compared with older parallel programmers. In a migration, engineers typically re-map the I/O registers, re-verify the ADC channel assignments, and re-check the fuse and lock-bit settings; the trade-off is that the 15 MHz speed grade may require a faster crystal than the legacy 8 MHz design used, so the clock tree and supply decoupling must be reviewed before production.
Recommended
Serial Communication Gateway
The ATMEGA168-15AD serves as a serial communication gateway because it integrates a programmable USART, a master/slave SPI interface, and a byte-oriented two-wire serial interface on one die, allowing it to bridge RS-232, SPI sensor buses, and I2C peripherals without external bridge chips. At 15 MHz the core handles protocol framing, checksum verification, and buffer management in firmware, while the 1 KB SRAM holds transmit and receive queues. A typical gateway runs a USART receive interrupt that forwards packets to an SPI or I2C slave; the trade-off is that 1 KB SRAM limits queue depth at high baud rates, so flow control or external buffering is recommended above 115.2 kbaud.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168-15AD — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168PA-AU | ATMEGA168V-10AU | ATMEGA88-15AD | ATMEGA168PA-15MZ |
|---|---|---|---|---|---|
| Package | 32-pin TQFP | 32-pin TQFP - same | 32-pin TQFP - same | 32-pin TQFP - same | 32-pad QFN/MLF |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 16 KB | 16 KB | 16 KB | 8 KB | 16 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 512 B | 1 KB |
| EEPROM | 512 B | 512 B | 512 B | 512 B | 512 B |
| Maximum Clock Speed | 15 MHz | 20 MHz | 10 MHz | 15 MHz | 15 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| General Purpose I/O | 23 | 23 | 23 | 23 | 23 |
| ADC | 8-channel, 10-bit | 8-channel, 10-bit | 8-channel, 10-bit | 8-channel, 10-bit | 8-channel, 10-bit |
| Serial Interfaces | USART, SPI, Two-wire (I2C) | USART, SPI, Two-wire (I2C) | USART, SPI, Two-wire (I2C) | USART, SPI, Two-wire (I2C) | USART, SPI, Two-wire (I2C) |
Key Differentiators
- 15 MHz automotive speed grade in a 32-pin TQFP (vs ATMEGA168V-10AU)
- Double the flash and SRAM of the ATmega88 family (vs ATMEGA88-15AD)
- Wide 2.7 V to 5.5 V supply range (vs ATMEGA168PA-AU)
Design Notes
Decouple every VCC and AVCC pin with a 100 nF ceramic capacitor placed within a few millimeters of the pin, and add a 10 uF bulk capacitor at the board entry. The AVCC pin supplies the ADC and must be filtered separately from the digital VCC rail, ideally through a ferrite bead or a small series resistor, to keep switching noise out of the analog conversion path. Keep the AREF pin bypassed to ground with a 100 nF capacitor when using the internal reference.
Route the crystal between XTAL1 and XTAL2 with the shortest possible traces and place the two load capacitors symmetrically on either side of the crystal, with a solid ground plane beneath. Keep the crystal away from the SPI and USART traces to avoid coupling. For the 32-pin TQFP, connect the exposed thermal pad area to ground with multiple vias if the package variant includes one, and keep the RESET pin pulled high through a 10 kOhm resistor with a 100 nF capacitor to ground for reliable power-on reset.
Do not exceed the 15 MHz maximum clock rate of the -15 speed grade; running the device above its rated frequency can cause flash read corruption and unpredictable execution. Verify the fuse and lock-bit settings before production, because an incorrect clock-source fuse can leave the device unresponsive to the SPI programmer. Also confirm the supply voltage stays within 2.7 V to 5.5 V across the full temperature range, since ADC accuracy and flash endurance degrade outside the specified operating window.
Compliance Information
The verified web data does not explicitly state RoHS, REACH, AEC-Q100, lead-free, or halogen-free status for the ATMEGA168-15AD ordering code. The part is positioned for automotive/industrial use, but qualification must be confirmed with Microchip before use in regulated designs.
