ATMEGA8535-16JU - 8-bit AVR MCU 16MHz 8KB Flash 44-PLCC | Microchip
MPN: ATMEGA8535-16JU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.08 | $5.08 |
| 10 | $4.6 | $46.00 |
| 100 | $4.1 | $410.00 |
| 500 | $3.7 | $1,850.00 |
| 1,000 | $3.35 | $3,350.00 |
ATMEGA8535-16JU Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, program memory, data memory, and peripheral functions such as timers, serial interfaces, and analog-to-digital converters. The ATMEGA8535 belongs to the AVR ATmega family, which sits within the broader hierarchy of 8-bit microcontrollers under the embedded processors category. AVR cores use a Harvard architecture with most instructions executing in a single clock cycle, distinguishing them from multi-cycle 8051-class MCUs.
Key features include the Advanced RISC architecture with 130 powerful instructions, 32 general-purpose 8-bit working registers, In-System Programming (ISP), and a supply voltage range of 4.5 V to 5.5 V for the 16 MHz speed grade. Peripheral set comprises three timers (two 8-bit, one 16-bit with PWM), an 8-channel 10-bit ADC, USART, SPI, TWI (I2C-compatible) serial interfaces, and an on-chip analog comparator.
Architecturally, the AVR pipeline fetches one instruction while executing another, achieving one MIPS per MHz of clock. Single-cycle ALU operation through the 32-register file eliminates the accumulator bottleneck of traditional 8-bit cores, improving code density and real-time determinism.
Typical applications include industrial motor control, HVAC and building automation, battery chargers, and instrumentation front ends that exploit the 8-channel 10-bit ADC.
Design consideration: the 16 MHz speed grade requires a 4.5 V to 5.5 V supply; a 3.3 V design must select the ATmega8535L-8 speed grade instead.
This page synthesizes distributor pricing, drop-in alternatives, design notes, and application guidance not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8535-16JU — 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 ATMEGA8535-16JU (same form factor and footprint) — differing in Package, Timers, Core Architecture, Instructions, Throughput.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8535-16JI
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA8535-16JC
✅ Drop-In✓ In Stock
$3.25 / Unit
View Datasheet →ATMEGA8535L-8JU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.72 / Unit
View Datasheet →ATMEGA8515-16JU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.1 / Unit
View Datasheet →ATMEGA8515-16JI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.44 / Unit
View Datasheet →ATMEGA8535-16JU Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Flash Memory | 8 KB (4K x 16) |
| SRAM | 512 B |
| EEPROM | 512 B |
| Clock Speed | 16 MHz |
| Throughput | 16 MIPS |
| Supply Voltage | 4.5 V to 5.5 V |
| ADC | 8-channel, 10-bit |
| I/O Ports | 23 (32 programmable I/O lines) |
| Timers | Two 8-bit, one 16-bit |
| Serial Interfaces | USART, SPI, TWI (I2C-compatible) |
| Instructions | 130 instructions, most single-cycle |
| Package | 44-PLCC (16.6 x 16.6 mm), J-Lead |
| Mounting Type | Surface Mount |
| Life Cycle Stage | Active |
ATMEGA8535-16JU 44-plcc (16.6 x 16.6 mm), j-lead Pin Configuration Guide
Pin configuration for ATMEGA8535-16JU (44-plcc (16.6 x 16.6 mm), j-lead 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 ATMEGA8535-16JU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA8535-16JU is suitable for 6 applications: Industrial Control and Automation, HVAC and Building Automation, Battery Chargers and Power Management, Instrumentation and Data Acquisition, Embedded Motor Control, Legacy Design Maintenance and Repair.
Industrial Control and Automation
The ATMEGA8535-16JU fits industrial control nodes that need deterministic 8-bit control, moderate memory, and native 5 V I/O. Its AVR core delivers 16 MIPS at 16 MHz, giving single-cycle instruction execution for tight real-time control loops, while the 4.5 V to 5.5 V supply range connects directly to legacy 24 V industrial panels via a linear or switching 5 V rail. The 32 programmable I/O lines drive relays, contactors, and status indicators; USART, SPI, and TWI interfaces link to HMI displays, EEPROM logs, and RS-485 transceivers. PLCC J-lead construction withstands vibration better than fine-pitch QFP in harsh cabinets, and ISP allows field firmware updates without desoldering.
Recommended
HVAC and Building Automation
In HVAC controllers, the ATMEGA8535-16JU combines the analog inputs and timers needed for temperature, humidity, and pressure monitoring in one 5 V device. The 8-channel 10-bit ADC reads multiple NTC thermistors or 0-10 V conditioned sensor inputs simultaneously, while the 16-bit timer with PWM drives damper actuators, valve servos, and variable-speed fan outputs. 512 B EEPROM stores setpoints and configuration across power cycles, and the TWI interface connects to real-time clocks and I2C displays. Throughput of 16 MIPS leaves ample headroom for PID loops on several zones, and In-System Programming lets building managers update control firmware through a maintenance header.
Recommended
Battery Chargers and Power Management
Battery charger controllers benefit from the ATMEGA8535-16JU's analog and timing resources: the 8-channel 10-bit ADC monitors cell voltage, charge current via shunt sense, and temperature (NTC) inputs, while the 16-bit timer generates PWM for buck-converter charge stages at resolutions suitable for CC/CV profiles. The 5 V supply matches common opto-isolated feedback circuits in offline chargers. Its EEPROM stores charge-profile tables per chemistry, and the USART logs charge events to service tools. Deterministic single-cycle AVR execution keeps state machines responsive at the millisecond charging deadlines, and the PLCC package's larger pitch simplifies repair in serviceable industrial charger hardware.
Recommended
Instrumentation and Data Acquisition
For low-cost instrumentation front ends, the ATMEGA8535-16JU's 8-channel 10-bit ADC with on-chip sample-and-hold digitizes up to eight sensor inputs without external conversion ICs, at roughly 15 ksps conversion rates. The analog comparator and internal bandgap reference support simple threshold alarms, while SPI streams readings to external SD storage or displays. The 16 MHz clock yields one MIPS per MHz for oversampling and averaging algorithms that push effective resolution beyond 10 bits. The 5 V rail simplifies interfacing with analog signal conditioning built around legacy op-amps, and 512 B EEPROM stores calibration coefficients per unit, supporting in-field recalibration via the USART service port.
Recommended
Embedded Motor Control
Small DC and stepper motor drives are a natural fit: the 16-bit timer with PWM output synthesizes 8- to 10-bit duty cycles at audible-to-20 kHz frequencies for smooth torque control, and two 8-bit timers handle sequencing and tachometer input capture. The 8-channel 10-bit ADC reads back motor current, bus voltage, and thermistor temperature for protective derating. The AVR core's 16 MIPS at 16 MHz executes commutation and PI current loops with deterministic latency, and 32 I/O lines interface to limit switches, encoders, and a status keypad. The 5 V PLCC device sits comfortably beside gate-driver ICs on the same logic rail in serviceable industrial drive boards.
Recommended
Legacy Design Maintenance and Repair
A substantial installed base of ATmega8535-based boards in industrial and test equipment remains in service, making the -16JU the correct procurement choice for sustaining engineering. Because the part is still active and available through Rochester Electronics fulfillment at DigiKey, stocking a maintenance spares pool is practical. Firmware compiled for the original ATmega8535 runs unmodified, fuse settings carry over, and the PLCC-44 socket allows replacement without hot-air rework - a technician can swap a failed device in minutes. This makes the -16JU preferable to modernizing the PCB with a TQFP part like ATmega32, which would demand new board layout, requalification, and firmware regression testing.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8535-16JU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8535-16JI | ATMEGA8535-16JC | ATMEGA8535L-8JU | ATMEGA8515-16JU |
|---|---|---|---|---|---|
| Package | 44-PLCC (16.6 x 16.6 mm) | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| Max Clock Speed | 16 MHz | 16 MHz | 16 MHz | 8 MHz | 16 MHz |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V | 4.5 V to 5.5 V |
| ADC Channels | 8-channel, 10-bit | 8-channel, 10-bit | 8-channel, 10-bit | 8-channel, 10-bit | 1-channel, 10-bit |
| SRAM / EEPROM | 512 B / 512 B | 512 B / 512 B | 512 B / 512 B | 512 B / 512 B | 512 B / 512 B |
Key Differentiators
- Full-speed 5 V operation at 16 MHz in PLCC-44 (vs ATMEGA8535L-8JU)
- Eight-channel 10-bit ADC in the legacy family (vs ATMEGA8515-16JU)
- Same-die temperature-grade flexibility (vs ATMEGA8535-16JI)
Design Notes
The 16 MHz speed grade requires VCC between 4.5 V and 5.5 V; below 4.5 V the clock limit drops. Decouple AVCC separately from VCC with an LC filter (10 uH inductor, 100 nF ceramic) to keep ADC noise low, and tie AREF to a clean reference with a 100 nF bypass when using external references. Estimated: at 16 MHz and 5 V, active current is typically in the low-tens of mA per the AVR generation's characteristics; budget regulator headroom of at least 50 mA for the MCU plus I/O loads.
Fuse configuration is the most common bring-up failure: CKOPT and the clock-source fuses must match your crystal setup, and clearing the SPIEN fuse over ISP can lock the device, requiring a high-voltage parallel programmer for recovery. Always program clock fuses last and verify readback. The PLCC-44 socket numbering runs counter-clockwise from the index mark - a rotated or off-by-one socketed device presents as a dead board rather than a damaged part. Also note RESET must be held below 0.3 x VCC with a 10 k pull-up during power-up for reliable startup.
Keep the crystal within 10-15 mm of XTAL1/XTAL2 with short return traces, and place 100 nF decoupling capacitors within 3 mm of each VCC/AVCC pin. For the ADC, route analog sense traces away from PWM and clock lines, and use a star ground connecting AGND and DGND at a single point near the device. If the PLCC is socketed, add local bypassing on the socket side as well - long socket leads add inductance that degrades supply integrity at 16 MHz.
At 16 MHz with fast AVR edge rates, keep SPI and USART clock traces under 20 cm and series-terminate (22-33 ohm) any lines longer than that to control ringing. TWI buses need external pull-ups sized for bus capacitance - 4.7 k is typical at 100 kHz with modest capacitance. Unused I/O pins should be configured as inputs with internal pull-ups or driven low as outputs to prevent floating-node EMI and excess current draw, per AVR application note guidance on uninitialized port pins.
Compliance Information
Compliance status not explicitly stated in the provided web data for this suffix; verify via Microchip product page material declarations or distributor compliance certificates.
