ATMEGA88A-MMHR - 8KB AVR MCU, 20MHz, VQFN-28 | Microchip
MPN: ATMEGA88A-MMHR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.42 | $1.42 |
| 10 | $1.28 | $12.80 |
| 100 | $1.12 | $112.00 |
| 500 | $0.98 | $490.00 |
| 1,000 | $0.86 | $860.00 |
ATMEGA88A-MMHR Overview
An 8-bit AVR microcontroller is a single-chip computer built around the AVR enhanced RISC architecture, executing powerful instructions in a single clock cycle. Within the system hierarchy, it belongs to the microcontroller family (MCU -> embedded processor -> integrated circuit), integrating CPU, program Flash, data SRAM, EEPROM, timers and peripherals on one die, eliminating external memory chips in cost- and space-sensitive designs.
Key features include the advanced RISC core with 131 instructions, most single-cycle, delivering close to 20 MIPS at 20 MHz; two 8-bit timers, one 16-bit timer and a 10-bit 8-channel ADC; plus USI (Universal Serial Interface) and one full-duplex USART for serial connectivity. In-System Programmable (ISP) Flash with read-while-write support enables field firmware updates through the SPI interface using tools such as the MPLAB SNAP.
The ATmega88A achieves throughput up to 20 MIPS at 20 MHz at 1.8V-5.5V operation, letting designers trade speed against power consumption. Its interrupt-driven picoPower sleep modes (idle, ADC noise reduction, power-down, power-save, standby) cut consumption to microamp levels in battery products.
Typical applications include industrial sensor nodes and control panels, consumer appliance user interfaces, battery-powered metering, and hobby/embedded platforms using Arduino-compatible bootloaders. The 4x4 mm VQFN suits compact two-layer PCBs where a TQFP-32 footprint is too large.
Design consideration: the 28-VQFN/MLF center pad must be soldered to a grounded copper pour, both for 0V connection and heat dissipation; plan reflow soldering rather than hand rework.
This page synthesizes distributor pricing context, drop-in alternatives, pinout, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA88A-MMHR — 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 ATMEGA88A-MMHR (same form factor and footprint) — differing in Package, Communication Interfaces, SRAM, RoHS Status, Flash Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA88PA-MMHR
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →ATMEGA168A-MMHR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.58 / Unit
View Datasheet →ATMEGA328-MMHR
✅ Drop-In✓ In Stock
$1.8 / Unit
View Datasheet →ATMEGA48A-MMHR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATMEGA168PA-MMHR
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA88A-MMHR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Program Flash Memory | 8 KB (4K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Number of I/O Lines | 23 |
| ADC Resolution | 10-bit |
| ADC Channels | 8 (6 multiplexed + ADC6/ADC7) |
| Timers/Counters | 2 x 8-bit, 1 x 16-bit |
| Communication Interfaces | 1 x USART, 1 x USI (SPI/I2C-compatible), 1-wire |
| PWM Channels | 3 (on-chip) |
| In-System Programming | Yes (ISP via SPI, read-while-write) |
| Package | 28-VQFN (4x4 mm MLF) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (Green) |
| Packing | Tape & Reel |
ATMEGA88A-MMHR Pin Configuration
| Pin 1 | PD3 — Port D bit 3 (GPIO / analog comparator / INT1) |
| Pin 2 | PD4 — Port D bit 4 (GPIO / XCK / TO1) |
| Pin 3 | VCC — Digital supply voltage |
| Pin 4 | GND — Ground |
| Pin 5 | PB6 — Port B bit 6 / XTAL1 (oscillator input; GPIO if internal RC used) |
| Pin 6 | PB7 — Port B bit 7 / XTAL2 (oscillator output; GPIO if internal RC used) |
| Pin 7 | PD5 — Port D bit 5 (GPIO / T1 / OC0B) |
| Pin 8 | PD6 — Port D bit 6 (GPIO / AIN0 / OC0A) |
| Pin 9 | PD7 — Port D bit 7 (GPIO / AIN1) |
| Pin 10 | PB0 — Port B bit 0 (GPIO / XCK / T0) |
| Pin 11 | PB1 — Port B bit 1 (GPIO / T1 / OC1A) |
| Pin 12 | PB2 — Port B bit 2 (GPIO / SS / OC1B) |
| Pin 13 | PB3 — Port B bit 3 (GPIO / MOSI / OC2A) |
| Pin 14 | PB4 — Port B bit 4 (GPIO / MISO) |
| Pin 15 | PB5 — Port B bit 5 (GPIO / SCK) |
| Pin 16 | AVCC — ADC supply voltage |
| Pin 17 | ADC6 — ADC input channel 6 (dedicated analog input) |
| Pin 18 | AREF — ADC analog reference |
| Pin 19 | GND — Ground |
| Pin 20 | ADC7 — ADC input channel 7 (dedicated analog input) |
| Pin 21 | PC0 — Port C bit 0 (GPIO / ADC0 / SCL / PCINT8) |
| Pin 22 | PC1 — Port C bit 1 (GPIO / ADC1 / SDA / PCINT9) |
| Pin 23 | PC2 — Port C bit 2 (GPIO / ADC2 / T0 / PCINT10) |
| Pin 24 | PC3 — Port C bit 3 (GPIO / ADC3 / T1 / PCINT11) |
| Pin 25 | PC4 — Port C bit 4 (GPIO / ADC4 / SDA / PCINT12) |
| Pin 26 | PC5 — Port C bit 5 (GPIO / ADC5 / SCL / PCINT13) |
| Pin 27 | PC6 — Port C bit 6 / RESET (active-low reset) |
| Pin 28 | PD0 — Port D bit 0 (GPIO / RXD / PCINT16) |
Typical Applications
ATMEGA88A-MMHR is suitable for 6 applications: Industrial Sensor Nodes and Control Panels, Battery-Powered Metering and Portables, Consumer Appliance User Interfaces, Embedded Hobby and Arduino-Compatible Boards, Motor and LED Control Subsystems, Data Acquisition and Test Instrument Front-Ends.
Industrial Sensor Nodes and Control Panels
The ATMEGA88A-MMHR fits industrial sensing and panel-control nodes because its 10-bit ADC with 8 channels digitizes multiple analog sensors (temperature, pressure, potentiometer setpoints) without external conversion ICs, while the USART and USI provide Modbus-style UART and I2C/SPI links to displays and actuators. Operating from 1.8V to 5.5V lets the MCU run directly from a 5V industrial rail or a 3.3V logic domain. Its 23 I/O lines drive relays, LEDs and keypads, and the 20 MIPS core handles filtering and state machines with margin. The 4x4 mm VQFN package keeps controller PCBs compact inside DIN-rail housings.
Recommended
Battery-Powered Metering and Portables
Battery products benefit from the ATmega88A's power-management strategy: run the 20 MHz core only during burst computations, then drop into power-down sleep where consumption falls to microamp territory. The picoPower-style sleep modes (idle, ADC noise reduction, power-save, standby, extended standby) support wake-on-interrupt designs typical of water/gas meters and portable instruments. The internal RC oscillator removes the crystal and its ~0.5-1 mA-class oscillator budget in low-speed modes, and the brown-out detector protects EEPROM writes during battery sag. With 512 B EEPROM, calibration data and consumption logs survive power loss without external NVM.
Recommended
Consumer Appliance User Interfaces
Appliance front panels - coffee machines, cooktops, HVAC thermostats - use the ATMEGA88A-MMHR to scan capacitive or membrane keypads, drive 7-segment/LED matrices via multiplexed I/O and generate buzzer tones from the 8-bit timers. The USI in SPI mode drives LED display drivers while the USART handles a UART link to a main control board. Three PWM channels dim indicator LEDs or drive small fans. Cost-sensitive appliance BOMs favor this MCU because the integrated ADC, timers, EEPROM and oscillator eliminate several discrete components, and the 8 KB Flash comfortably holds UI state machines and lookup tables.
Recommended
Embedded Hobby and Arduino-Compatible Boards
The ATmega88 family is widely used in maker and educational boards thanks to open-source AVR toolchains (avrdude, avr-gcc) and Arduino-compatible bootloaders. The ATMEGA88A-MMHR's ISP Flash with read-while-write lets the bootloader reprogram the application over the built-in USART using an FTDI-style USB-serial cable - the same workflow as an Arduino Uno based on the related ATmega328P. The MPLAB SNAP programmer connects through a simple SIL header using two I/O pins and reset for both debugging and ICSP. Its 4x4 mm QFN suits small wearable-style shields where through-hole DIP packages are impractical.
Recommended
Motor and LED Control Subsystems
With two 8-bit timers and one 16-bit timer, the ATMEGA88A-MMHR generates three hardware PWM channels suitable for DC motor speed control (via a small H-bridge or MOSFET driver), RGB LED dimming at high PWM frequencies, and servo positioning. The 16-bit timer provides precise input capture for tachometer or hall-sensor feedback, closing speed-control loops in fans, pumps and small robotics. The 10-bit ADC reads current-sense shunts and potentiometer commands, while the interrupt structure keeps PWM jitter low under communication load. Running at 20 MHz gives 8-bit PWM resolutions well above audible frequencies for fan and lighting applications.
Recommended
Data Acquisition and Test Instrument Front-Ends
Low-cost DAQ modules and instrument front-ends use the ATMEGA88A-MMHR's 10-bit ADC in differential mode with selectable gain to sample sensor bridges, while the ADC noise reduction sleep mode suppresses digital core activity during conversions for cleaner readings. The USART streams results to a host at standard baud rates, and 1 KB SRAM buffers acquisition blocks before transmission. Timer input capture timestamps external pulse events (flow meters, encoders) with clock-cycle resolution at 20 MHz. The 512 B EEPROM stores factory calibration constants per unit, supporting traceable multi-point calibration without external memory ICs on the module PCB.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA88A-MMHR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA88PA-MMHR | ATMEGA168A-MMHR | ATMEGA328-MMHR | ATMEGA48A-MMHR |
|---|---|---|---|---|---|
| Package | 28-VQFN (4x4 mm MLF) | 28-VQFN (4x4 mm MLF) - same | 28-VQFN (4x4 mm MLF) - same | 28-VQFN (4x4 mm MLF) - same | 28-VQFN (4x4 mm MLF) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 8 KB | 8 KB | 16 KB | 32 KB | 4 KB |
| EEPROM | 512 B | 512 B | 512 B | 1 KB | 256 B |
| SRAM | 1 KB | 1 KB | 1 KB | 2 KB | 512 B |
| Max Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Power Generation | ATmega88A (previous low-power gen) | picoPower (lower sleep current) | standard | standard | standard |
Key Differentiators
- Latest A-generation core in the smallest industrial package option (vs ATMEGA88-20MU / older ATmega88)
- Lower power upgrade path without respin (vs ATMEGA88PA-MMHR)
- Memory scalability on one footprint (vs ATMEGA168A-MMHR / ATMEGA328-MMHR)
Design Notes
The 28-VQFN (MLF) exposed center pad is the primary ground connection. Design the PCB land pattern with a solder-mask-defined center pad of about 2.5x2.5 mm and a via array (3x3 minimum) to the ground plane for reliable reflow wetting and heat spreading. QFN packages cannot be reliably hand-soldered with an iron; use reflow or hot-plate assembly, and inspect with X-ray or angled optical inspection for center-pad voids that would leave the die floating above ground.
Decouple VCC and AVCC separately with 100 nF ceramic capacitors placed within 5 mm of each pin, plus a bulk 4.7-10 uF capacitor per rail. AVCC must be connected to VCC even when the ADC is unused, and should be filtered through an LC or RC network (e.g., 10R + 1 uF) in ADC-heavy designs to keep conversion noise low. Tie AREF to a 100 nF capacitor (or external reference); never drive AREF while the internal reference is selected, as this can damage the reference amplifier.
Two frequent pitfalls with this part: (1) setting the RSTDISBL fuse disables the external reset pin permanently and makes the device very difficult to reprogram with ISP - avoid unless the pin is absolutely needed as I/O; (2) clock-source fuses (CKSEL/SUT) must match your hardware - selecting external crystal mode without a crystal bricks ISP access until a clock is injected. Always set lock/fuse bits through avrdude or MPLAB IPE with a documented profile, and keep RESET (PC6) routed to the ICSP header.
Keep the crystal (PB6/PB7) traces as short as possible, below 10 mm, with load capacitors grounded directly to the MCU ground pad. Route the USART and SPI lines away from the ADC input traces and the AREF node; ground-guard unused ADC inputs to GND or configure them as outputs low to prevent floating input crosstalk. For ADC accuracy above 8 effective bits, sample during ADC noise reduction sleep mode and average 4-16 readings.
Compliance Information
Listed as Green by distributor FindIC; RoHS compliant and lead-free. Automotive qualification (AEC-Q100) is not claimed for this ordering code.
