STM8AL3L66TCY - 8-bit Ultra-Low-Power MCU 64KB Flash | STMicroelectronics
MPN: STM8AL3L66TCY β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.25 | $3.25 |
| 10 | $2.95 | $29.50 |
| 100 | $2.45 | $245.00 |
| 500 | $2.1 | $1,050.00 |
| 1,000 | $1.85 | $1,850.00 |
Drop-in alternatives for STM8AL3L66TCY β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
STM8AL3L68TCY
β Drop-Inπ Reference alternative (not in catalog)
STM8AL3L46TCY
β Drop-Inβ 99,999 In Stock
$1.82 / Unit
View Datasheet βSTM8AL3L88TCY
β Drop-Inβ 99,999 In Stock
$1.85 / Unit
View Datasheet βSTM8L151C6T6
β‘ Same Packageπ Reference alternative (not in catalog)
STM8AL3L66TCY Maximum Ratings & Electrical Characteristics
| Core | STM8 8-bit |
| Maximum Clock Frequency | 16 MHz |
| Flash Memory | 64 KB |
| RAM | 4 KB |
| Supply Voltage Range | 1.8 V to 3.6 V |
| Package | LQFP-48 |
| Operating Temperature Range | -40C to +85C |
| ADC Resolution | 12-bit |
| ADC Channels | 16 |
| Comparators | 2 |
| Timers | 16-bit and 12-bit |
| Communication Interfaces | I2C, SPI, UART |
| Real-Time Clock | Yes (with calendar) |
| Low-Power Modes | Wait, Active-Halt, Halt |
| Halt Mode Current | 0.6 Β΅A (typical) |
| Debug Interface | SWIM |
| RoHS Status | Compliant |
STM8AL3L66TCY Pin Configuration
| Pin 1 | VDD β Power supply |
| Pin 2 | VSS β Ground |
| Pin 3 | PA0 β General purpose I/O / ADC input |
| Pin 4 | PA1 β General purpose I/O / ADC input |
| Pin 5 | PA2 β General purpose I/O / ADC input |
| Pin 6 | PA3 β General purpose I/O / ADC input |
| Pin 7 | PA4 β General purpose I/O / ADC input |
| Pin 8 | PA5 β General purpose I/O / ADC input |
| Pin 9 | PA6 β General purpose I/O / ADC input |
| Pin 10 | PA7 β General purpose I/O / ADC input |
| Pin 11 | PB0 β General purpose I/O |
| Pin 12 | PB1 β General purpose I/O |
| Pin 13 | PB2 β General purpose I/O |
| Pin 14 | PB3 β General purpose I/O |
| Pin 15 | PB4 β General purpose I/O |
| Pin 16 | PB5 β General purpose I/O |
| Pin 17 | PB6 β General purpose I/O |
| Pin 18 | PB7 β General purpose I/O |
| Pin 19 | PC0 β General purpose I/O / ADC input |
| Pin 20 | PC1 β General purpose I/O / ADC input |
| Pin 21 | PC2 β General purpose I/O / ADC input |
| Pin 22 | PC3 β General purpose I/O / ADC input |
| Pin 23 | PC4 β General purpose I/O / ADC input |
| Pin 24 | PC5 β General purpose I/O / ADC input |
| Pin 25 | PC6 β General purpose I/O |
| Pin 26 | PC7 β General purpose I/O |
| Pin 27 | PD0 β General purpose I/O / UART |
| Pin 28 | PD1 β General purpose I/O / UART |
| Pin 29 | PD2 β General purpose I/O |
| Pin 30 | PD3 β General purpose I/O |
| Pin 31 | PD4 β General purpose I/O |
| Pin 32 | PD5 β General purpose I/O |
| Pin 33 | PD6 β General purpose I/O |
| Pin 34 | PD7 β General purpose I/O |
| Pin 35 | PE0 β General purpose I/O |
| Pin 36 | PE1 β General purpose I/O |
| Pin 37 | PE2 β General purpose I/O |
| Pin 38 | PE3 β General purpose I/O |
| Pin 39 | PE4 β General purpose I/O |
| Pin 40 | PE5 β General purpose I/O |
| Pin 41 | PE6 β General purpose I/O |
| Pin 42 | PE7 β General purpose I/O |
| Pin 43 | NRST β Reset |
| Pin 44 | VDD β Power supply |
| Pin 45 | VSS β Ground |
| Pin 46 | VDDIO β I/O power supply |
| Pin 47 | VSSIO β I/O ground |
| Pin 48 | SWIM β Debug interface |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
STM8AL3L66TCY is suitable for 6 applications: Smart Meters, Portable Medical Devices, Sensor Nodes, Industrial Control, Wearable Devices, Home Automation.
Smart Meters
The STM8AL3L66TCY is ideal for smart meters due to its ultra-low-power consumption and integrated ADC for accurate measurement. In a typical smart meter, the MCU reads voltage and current sensors via the 12-bit ADC, processes the data, and communicates via UART or I2C to a display or communication module. The Halt mode with 0.6 Β΅A current ensures long battery life, while the RTC maintains timekeeping. The 64 KB Flash allows storing calibration data and firmware updates. Compared to higher-power MCUs, the STM8AL3L66TCY reduces overall system power, extending battery life by up to 30%.
Recommended
Portable Medical Devices
The STM8AL3L66TCY is well-suited for portable medical devices like glucose meters and pulse oximeters. Its low-power modes and 1.8V operation allow direct battery powering. The 12-bit ADC accurately reads sensor signals, and the UART interface enables data transfer to a host. The small LQFP-48 package fits compact designs. In a glucose meter, the MCU samples the sensor, calculates glucose levels, and displays results on an LCD. The Halt mode between measurements conserves battery, enabling months of operation on a single coin cell. The wide temperature range ensures reliable operation in various environments.
Recommended
Sensor Nodes
The STM8AL3L66TCY is perfect for wireless sensor nodes in IoT applications. Its ultra-low-power consumption allows battery-powered operation for years. The MCU periodically wakes from Halt mode, reads sensors via ADC or I2C, and transmits data via UART to a radio module. The 16 MHz clock provides sufficient processing for data filtering. The RTC can schedule wake-ups, and the 64 KB Flash stores sensor calibration. In a temperature monitoring node, the MCU wakes every minute, reads a temperature sensor, and sends data via a 433 MHz radio. The low power consumption ensures a battery life of over 5 years.
Recommended
Industrial Control
The STM8AL3L66TCY is used in industrial control systems for monitoring and control tasks. Its robust design and wide temperature range make it suitable for factory automation. The MCU can interface with sensors, actuators, and communication buses. The 12-bit ADC reads analog sensors, while the timers generate PWM for motor control. The UART and SPI interfaces allow connection to industrial networks. In a conveyor belt controller, the MCU monitors speed sensors, adjusts motor speed via PWM, and communicates with a PLC via Modbus over UART. The low-power modes reduce energy consumption during idle periods.
Recommended
Wearable Devices
The STM8AL3L66TCY is ideal for wearables like fitness trackers and smartwatches. Its small package and low power consumption enable compact, battery-efficient designs. The MCU can process sensor data from accelerometers and heart rate monitors, and communicate via BLE through an external module. The 1.8V operation allows direct connection to a Li-ion battery. In a fitness tracker, the MCU reads an accelerometer via I2C, counts steps, and displays data on an OLED. The Halt mode between readings extends battery life to several weeks. The 64 KB Flash stores firmware and user data.
Recommended
Home Automation
The STM8AL3L66TCY is used in home automation devices like smart thermostats and lighting controls. Its low power consumption and rich peripherals make it suitable for always-on devices. The MCU can control relays, read temperature sensors, and communicate via Zigbee or Wi-Fi modules. In a smart thermostat, the MCU reads a temperature sensor, compares it to the setpoint, and controls a relay for the HVAC system. The RTC schedules temperature changes, and the UART communicates with a Wi-Fi module for remote control. The low-power modes reduce energy consumption when idle.
Recommended
Recommended Products Summary
Engineering reference data for STM8AL3L66TCY β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM8AL3L68TCY | STM8AL3L46TCY | STM8AL3L88TCY | STM8L151C6T6 |
|---|---|---|---|---|---|
| Package | LQFP-48 | LQFP-48 | LQFP-48 | LQFP-48 | LQFP-48 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Flash Memory | 64 KB | 128 KB | 32 KB | 128 KB | 32 KB |
| RAM | 4 KB | 4 KB | 2 KB | 6 KB | 2 KB |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| ADC Resolution | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit |
| Halt Mode Current | 0.6 Β΅A | 0.6 Β΅A | 0.6 Β΅A | 0.6 Β΅A | 1 Β΅A |
| Pin Compatibility | Reference | Yes | Yes | Yes | No |
Key Differentiators
- Ultra-low-power Halt mode current of 0.6 Β΅A (vs STM8L151C6T6)
- 64 KB Flash memory (vs STM8AL3L46TCY)
- Pin-compatible with higher-memory variants (vs STM8AL3L68TCY)
Design Notes
Decouple the VDD and VDDIO pins with 100nF and 10Β΅F capacitors placed close to the pins. Use a low-ESR ceramic capacitor for high-frequency noise. For battery-powered designs, consider using the Halt mode to reduce current to 0.6 Β΅A, and ensure the supply voltage does not drop below 1.8V during operation.
For the LQFP-48 package, ensure proper solder paste stencil design to avoid bridging. Place the crystal oscillator (if used) close to the MCU with short traces. Keep analog and digital grounds separate and connect at a single point to minimize noise.
Do not leave unused pins floating; configure them as outputs or enable internal pull-ups. Ensure the NRST pin is properly pulled up with a 100nF capacitor to ground to prevent spurious resets. When using the SWIM interface, keep the trace short to avoid signal integrity issues.
Compliance Information
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified.
