ATMEGA8535L-8AC - 8MHz AVR MCU, 8KB Flash, TQFP-44 | Microchip
MPN: ATMEGA8535L-8AC ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.68 | $46.80 |
| 100 | $4.16 | $416.00 |
| 500 | $3.75 | $1,875.00 |
| 1,000 | $3.38 | $3,380.00 |
ATMEGA8535L-8AC Overview
An AVR ATmega microcontroller is a member of the 8-bit microcontroller (MCU) family built on the AVR enhanced RISC architecture, which sits within the broader hierarchy of embedded processors used for sensing, control, and human-interface functions. AVR cores execute most of their 130 instructions in a single clock cycle, giving high code efficiency and deterministic timing for real-time embedded control.
Key features include 32 general purpose I/O lines, three flexible Timer/Counters with compare modes, a programmable serial USART, a byte-oriented Two-Wire Interface (TWI/I2C), and an SPI serial port. The L suffix denotes the wide 2.7 V to 5.5 V operating voltage range, allowing the same design to run from 3.3 V or 5 V rails at 0 to 8 MHz.
Architecturally, the device pairs the AVR RISC core with separate program and data buses (Harvard architecture), 32 general purpose working registers, and Read-While-Write self-programming Flash. Six sleep modes (Idle, ADC Noise Reduction, Power-save, Power-down, Standby, Extended Standby) cut quiescent draw dramatically in battery applications, and the 8-channel 10-bit ADC with internal reference supports direct analog sensor interfacing.
Typical applications include industrial control panels, sensor acquisition nodes using the ADC plus TWI/SPI peripherals, and motor or relay control systems where the three timers generate PWM outputs.
When designing, budget SRAM carefully - 512 bytes fills quickly with large buffers or deep call stacks - and validate brown-out/fuse settings for reliable 5 V operation.
This page synthesizes distributor pricing context, drop-in alternatives, pinout, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8535L-8AC — 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 ATMEGA8535L-8AC (same form factor and footprint) — differing in Package, SRAM, Operating Temperature, RoHS Status, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8535L-8AUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA8535-16AU
✅ Drop-In✓ In Stock
$3.48 / Unit
View Datasheet →ATMEGA8535-16MI
✅ Drop-In✓ In Stock
$3.35 / Unit
View Datasheet →ATMEGA16L-8AI
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA8515L-8AI
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →ATMEGA8535L-8AC Maximum Ratings & Electrical Characteristics
| Core | 8-bit AVR RISC |
| Program Memory (Flash) | 8 KB (4K x 16) |
| Flash Type | In-System Programmable, Read-While-Write |
| SRAM | 512 bytes |
| EEPROM | 512 bytes |
| Maximum Clock Frequency | 8 MHz |
| Operating Voltage Range | 2.7 V to 5.5 V |
| ADC | 8-channel, 10-bit |
| General Purpose I/O | 32 lines |
| Timers/Counters | 3 (two 8-bit, one 16-bit with compare modes) |
| USART | 1 x programmable serial USART |
| SPI | 1 x serial peripheral interface |
| TWI (I2C) | 1 x byte-oriented Two-Wire Serial Interface |
| Sleep Modes | 6 (Idle, ADC Noise Reduction, Power-save, Power-down, Standby, Extended Standby) |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (green per FindIC listing) |
ATMEGA8535L-8AC Pin Configuration
| Pin 1 | PA7 (ADC7) — Port A bit 7 / ADC channel 7 |
| Pin 2 | PA6 (ADC6) — Port A bit 6 / ADC channel 6 |
| Pin 3 | PA5 (ADC5) — Port A bit 5 / ADC channel 5 |
| Pin 4 | PA4 (ADC4) — Port A bit 4 / ADC channel 4 |
| Pin 5 | PA3 (ADC3) — Port A bit 3 / ADC channel 3 |
| Pin 6 | PA2 (ADC2) — Port A bit 2 / ADC channel 2 |
| Pin 7 | PA1 (ADC1) — Port A bit 1 / ADC channel 1 |
| Pin 8 | PA0 (ADC0) — Port A bit 0 / ADC channel 0 |
| Pin 9 | GND — Ground |
| Pin 10 | VCC — Digital supply voltage (2.7 V to 5.5 V) |
| Pin 11 | PB0 (XCK/T0) — Port B bit 0 / USART external clock / Timer0 external clock |
| Pin 12 | PB1 (T1) — Port B bit 1 / Timer1 external clock |
| Pin 13 | PB2 (AIN0/INT2) — Port B bit 2 / analog comparator positive input / external interrupt 2 |
| Pin 14 | PB3 (AIN1/OC0) — Port B bit 3 / analog comparator negative input / Timer0 output compare |
| Pin 15 | PB4 (SS) — Port B bit 4 / SPI slave select |
| Pin 16 | PB5 (MOSI) — Port B bit 5 / SPI master output slave input |
| Pin 17 | PB6 (MISO) — Port B bit 6 / SPI master input slave output |
| Pin 18 | PB7 (SCK) — Port B bit 7 / SPI serial clock |
| Pin 19 | RESET — Active-low reset input |
| Pin 20 | VCC — Digital supply voltage |
| Pin 21 | GND — Ground |
| Pin 22 | XTAL2 — Crystal oscillator output |
| Pin 23 | XTAL1 — Crystal oscillator input / external clock |
| Pin 24 | PD0 (RXD) — Port D bit 0 / USART receive |
| Pin 25 | PD1 (TXD) — Port D bit 1 / USART transmit |
| Pin 26 | PD2 (INT0) — Port D bit 2 / external interrupt 0 |
| Pin 27 | PD3 (INT1) — Port D bit 3 / external interrupt 1 |
| Pin 28 | PD4 (OC1B) — Port D bit 4 / Timer1 output compare B |
| Pin 29 | PD5 (OC1A) — Port D bit 5 / Timer1 output compare A |
| Pin 30 | PD6 (ICP1) — Port D bit 6 / Timer1 input capture |
| Pin 31 | PD7 (OC2) — Port D bit 7 / Timer2 output compare |
| Pin 32 | AREF — ADC analog reference |
| Pin 33 | AGND — Analog ground |
| Pin 34 | AVCC — ADC supply voltage |
| Pin 35 | PC0 (SCL) — Port C bit 0 / TWI serial clock |
| Pin 36 | PC1 (SDA) — Port C bit 1 / TWI serial data |
| Pin 37 | PC2 (TCK) — Port C bit 2 / JTAG test clock |
| Pin 38 | PC3 (TMS) — Port C bit 3 / JTAG test mode select |
| Pin 39 | PC4 (TDO) — Port C bit 4 / JTAG test data output |
| Pin 40 | PC5 (TDI) — Port C bit 5 / JTAG test data input |
| Pin 41 | PC6 (TOSC1) — Port C bit 6 / Timer2 oscillator input |
| Pin 42 | PC7 (TOSC2) — Port C bit 7 / Timer2 oscillator output |
| Pin 43 | GND — Ground |
| Pin 44 | VCC — Digital supply voltage |
Typical Applications
ATMEGA8535L-8AC is suitable for 6 applications: Industrial Control Panels, Analog Sensor Acquisition Nodes, Embedded Motor and Relay Control, Battery-Powered Instruments, Communication and Data Logging, Automotive Aftermarket and Test Fixtures.
Industrial Control Panels
The ATMEGA8535L-8AC fits industrial panel controllers because its 2.7 V to 5.5 V tolerance rides through unregulated 5 V logic supplies while its 32 GPIO lines drive relays, indicators, and keypads directly. The three Timer/Counters with compare modes generate PWM for actuator positioning, and the USART links to SCADA gateways at standard baud rates from the 8 MHz clock. Six sleep modes cut standby draw in always-on panels, and the 8 KB self-programming Flash permits field firmware updates over the existing serial link without a separate bootloader chip, reducing BOM cost in serviceable installations.
Recommended
Analog Sensor Acquisition Nodes
With an 8-channel 10-bit ADC on Port A, the ATMEGA8535L-8AC digitizes up to eight analog sensors directly - thermistors, strain bridges, and potentiometers - without an external converter. Running in the ADC Noise Reduction sleep mode suppresses digital switching noise during conversions for cleaner readings, and AREF/AGND/AVCC pins allow a precise external reference when sub-1% accuracy is required. Sampled data is timestamped by the 16-bit Timer/Counter, buffered in the 512-byte SRAM, and uploaded via TWI or SPI to a gateway, making the part a compact, single-chip front end for distributed monitoring nodes.
Recommended
Embedded Motor and Relay Control
The 16-bit Timer/Counter with two compare outputs (OC1A/OC1B on Port D) gives the ATMEGA8535L-8AC hardware PWM for DC motor speed control and servo positioning, while the external interrupt pins (INT0/INT1) capture encoder or limit-switch events with deterministic latency. Port B supports direct relay driver logic through ULN-class transistors, and the byte-oriented TWI interface supervises power-management ICs over I2C. Operating the L-grade die from 2.7 V to 5.5 V lets the same controller PCB serve both 3.3 V logic ecosystems and legacy 5 V industrial drivers without redesign of the supply section.
Recommended
Battery-Powered Instruments
The L-grade voltage window of 2.7 V to 5.5 V lets the ATMEGA8535L-8AC run directly from a 3 V lithium coin cell or two AA cells without a regulator, while six sleep modes - Power-down, Standby, Extended Standby, Idle, ADC Noise Reduction, and Power-save - slash average current between measurements. The 512-byte EEPROM stores calibration constants and user settings across battery replacement, and the wake-on-USART/TWI capability supports burst data uploads. Designs must budget the small SRAM for state rather than deep buffering, but for periodic sampling instruments the power profile and on-chip ADC eliminate the need for a companion converter or supervisor IC.
Recommended
Communication and Data Logging
A programmable USART, an SPI port, and a byte-oriented TWI interface give the ATMEGA8535L-8AC three simultaneous serial channels, enough for a data logger that records locally to EEPROM/external SPI flash while streaming to a host over RS-232/RS-485. The 8 MHz L-grade clock derives standard baud rates from a crystal on XTAL1/XTAL2 with low error, and Read-While-Write Flash allows logging into program-flash sectors or bootloader updates without stopping acquisition. Designs must respect the 512-byte SRAM ceiling by streaming records promptly, but the single-chip integration of interface plus timers makes compact multi-protocol logging hardware practical.
Recommended
Automotive Aftermarket and Test Fixtures
In off-core automotive aftermarket modules and production test fixtures, the ATMEGA8535L-8AC's fully static core tolerates noisy 5 V vehicle-logic supplies within its 2.7 V to 5.5 V window, and brown-out plus watchdog supervision maintain code integrity during cranking transients. The 8-channel 10-bit ADC reads analog test points, the timers emulate pulse-train sensor signals, and the USART bridges to bench PCs for logging. Its 44-TQFP footprint, also offered in industrial-grade L variants and the pin-compatible ATMEGA16L upgrade, gives fixture builders a stable, multi-source-adjacent controller platform that survives long tooling lifetimes with minimal redesign.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8535L-8AC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8535L-8AUR | ATMEGA8535-16AU | ATMEGA16L-8AI | ATMEGA8515L-8AI |
|---|---|---|---|---|---|
| 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 |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 8 KB | 8 KB | 8 KB | 16 KB | 8 KB |
| SRAM | 512 bytes | 512 bytes | 512 bytes | 1 KB | 512 bytes |
| EEPROM | 512 bytes | 512 bytes | 512 bytes | 512 bytes | 512 bytes |
| Max Clock | 8 MHz | 8 MHz | 16 MHz | 8 MHz | 8 MHz |
| Operating Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| 10-bit ADC Channels | 8 | 8 | 8 | 8 | None (no ADC) |
| Pin Compatibility | AVR 44-TQFP baseline | Pin-to-pin identical | Pin-to-pin identical | Pin-to-pin identical | Pin-to-pin identical |
Key Differentiators
- Wide 2.7 V to 5.5 V L-grade window (vs ATMEGA8535-16AU)
- Integrated 8-channel 10-bit ADC (vs ATMEGA8515L-8AI)
- 8 KB Flash ceiling (vs ATMEGA16L-8AI)
Design Notes
The 512-byte SRAM is the tightest resource on this part. Deep C call stacks plus string libraries (printf) can overflow silently into the hardware stack and corrupt data. Estimate worst-case stack depth at design time, keep ISR nesting to one level, and enable a software stack-overflow canary in debug builds. If buffers must grow, prefer streaming data out over TWI/USART immediately rather than accumulating in SRAM, or migrate to the pin-compatible ATMEGA16L-8AI with 1 KB SRAM.
Fuse configuration governs reliability and power: enable the brown-out detector (BOD) for 5 V operation to prevent Flash corruption during supply dips, and select the appropriate BOD threshold for 3.3 V rails per the datasheet's voltage-to-threshold table. For battery designs, use Power-down sleep plus the external interrupt or watchdog wake-up; measured active current scales directly with clock, so drop to a 32.768 kHz TOSC clock on PC6/PC7 during idle periods. Estimated: at 8 MHz active versus Power-down, duty-cycled systems see orders-of-magnitude average-current reductions.
Keep AVCC connected to VCC through a low-pass LC network (for example 10 uH and 100 nF, per datasheet typical schematic) even if the ADC is unused, and never leave AVCC or AGND floating. Place a 100 nF ceramic decoupling capacitor at each VCC pin (10, 20, 44) within a few millimeters of the pad, and route AREF with its own 100 nF to AGND away from digital clock traces. XTAL1/XTAL2 crystal loading capacitors should follow the crystal vendor's specified CL, typically 12-22 pF.
Port A doubles as the ADC input, so minimize digital switching and series-resistor protection mismatch on PA0-PA7 in analog designs; the datasheet recommends keeping source impedance below 10 kilo-ohm for accurate 10-bit sampling within the ADC clock budget. Set the ADC prescaler so the ADC clock lands in its recommended 50-200 kHz window for full 10-bit resolution - running it faster trades resolution for speed.
Compliance Information
Listed as GREEN (lead-free/RoHS) on distributor listings including FindIC. AEC-Q100 qualification not claimed for this part number; confirm with Microchip for automotive use.