STM8AL3166TA - Automotive 8-bit MCU, 32KB Flash, LQFP-32 | ST
MPN: STM8AL3166TA ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.52 | $4.52 |
| 10 | $4.07 | $40.70 |
| 100 | $3.62 | $362.00 |
| 500 | $3.26 | $1,630.00 |
| 1,000 | $2.9 | $2,900.00 |
| 3,000 | $2.61 | $7,830.00 |
STM8AL3166TA Overview
An 8-bit microcontroller (MCU) is a compact integrated circuit combining a low-power 8-bit CPU, program memory (Flash/ROM), data memory (RAM), and on-chip peripherals such as timers, ADC, and GPIO into a single package. The MCU sits at the hierarchy of microcontroller -> embedded processor -> semiconductor IC, serving as the brain of an embedded system for deterministic control tasks. The STM8AL medium-density line occupies the ultra-low-power, automotive-qualified tier of ST's 8-bit portfolio, designed for body electronics, sensor conditioning, and battery-powered ECUs.
Key features of the STM8AL3166TA include the proprietary STM8 core running at 16 MHz, AES-128 hardware encryption on most L variants, integrated LCD driver (on L3xxx derivatives), ultra-low-power modes with sub-microamp standby current, AEC-Q100 qualification for automotive deployment, and 32 KB of single-voltage Flash with in-application programming. The device supports 1.65 V to 3.6 V supply and provides robust ESD immunity specified in the family datasheet.
Architecturally, the STM8AL3166TA uses a Harvard-style architecture with separate program and data buses, a 16-bit stack pointer, and a 24-bit program counter that together enable linear 16 MB address space. The integrated voltage regulator, brown-out reset, and low-power real-time clock allow the part to operate for years from a single coin cell or automotive battery while still meeting strict quiescent-current budgets.
Typical applications include automotive body controllers, sensor nodes, remote keyless entry, instrument cluster sub-modules, HVAC control, and industrial low-power wireless sensor platforms. The wide operating temperature and AEC-Q100 grade make the device suitable for under-hood and chassis-mounted ECUs.
When designing with this MCU, allocate Flash for a robust bootloader to enable field firmware updates and leave at least one USART free for diagnostics. Use the brown-out reset and watchdog together to recover from corrupted supply or firmware states - this is essential for unattended automotive deployments.
This page synthesizes distributor pricing, drop-in alternatives from the same STM8AL family, and practical application guidance not found in the manufacturer datasheet alone, helping procurement and engineering teams make an informed component selection.
Drop-in alternatives for STM8AL3166TA — 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 STM8AL3166TA (same form factor and footprint) — differing in Operating Temperature, Package, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
STM8AL3166TAY
✅ Drop-In✓ In Stock
$0.73 / Unit
View Datasheet →STM8AL3168TA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8AL3164TA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8AL3146TAY
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.19 / Unit
View Datasheet →STM8AL3136TA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8L152R6T6A
✅ Drop-In📋 Reference alternative (not in catalog)
STM8AL3166TA Maximum Ratings & Electrical Characteristics
| Family | STM8AL medium-density |
| Core | STM8 8-bit |
| CPU Frequency | 16 MHz |
| Flash Memory | 32 KB |
| Supply Voltage | 1.65 V to 3.6 V |
| ADC | 12-bit |
| DAC | Yes |
| Comparators | 2 |
| 16-bit Timers | 3 |
| 8-bit Timers | 1 |
| RTC | Yes (with calendar) |
| Communication Interfaces | SPI, I2C, USART |
| Package | 32-LQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C (automotive grade) |
| AEC-Q100 | Qualified |
| RoHS Status | Compliant |
STM8AL3166TA Pin Configuration
| Pin 1 | NRST — Reset input (active low) |
| Pin 2 | OSCIN — Crystal oscillator input |
| Pin 3 | OSCOUT — Crystal oscillator output |
| Pin 4 | VSS — Digital ground |
| Pin 5 | VCAP — Voltage regulator stabilization capacitor |
| Pin 6 | VDD — Digital power supply |
| Pin 7 | PA1 — GPIO port A pin 1 |
| Pin 8 | PA2 — GPIO port A pin 2 |
| Pin 9 | PA3 — GPIO port A pin 3 |
| Pin 10 | VREF+ — ADC reference voltage positive |
| Pin 11 | VREF- — ADC reference voltage negative / analog ground |
| Pin 12 | PB0 — GPIO port B pin 0 / ADC input |
| Pin 13 | PB1 — GPIO port B pin 1 / ADC input |
| Pin 14 | PB2 — GPIO port B pin 2 / ADC input |
| Pin 15 | PB3 — GPIO port B pin 3 / ADC input |
| Pin 16 | PB4 — GPIO port B pin 4 / ADC input |
| Pin 17 | PB5 — GPIO port B pin 5 / ADC input |
| Pin 18 | PB6 — GPIO port B pin 6 / I2C SDA |
| Pin 19 | PB7 — GPIO port B pin 7 / I2C SCL |
| Pin 20 | PC0 — GPIO port C pin 0 |
| Pin 21 | PC1 — GPIO port C pin 1 |
| Pin 22 | PC2 — GPIO port C pin 2 |
| Pin 23 | PC3 — GPIO port C pin 3 |
| Pin 24 | PC4 — GPIO port C pin 4 |
| Pin 25 | PC5 — GPIO port C pin 5 |
| Pin 26 | PC6 — GPIO port C pin 6 / SPI |
| Pin 27 | PC7 — GPIO port C pin 7 / SPI |
| Pin 28 | PD0 — GPIO port D pin 0 / USART RX |
| Pin 29 | PD1 — GPIO port D pin 1 / USART TX |
| Pin 30 | PD2 — GPIO port D pin 2 |
| Pin 31 | PD3 — GPIO port D pin 3 |
| Pin 32 | PD4 — GPIO port D pin 4 |
Typical Applications
STM8AL3166TA is suitable for 6 applications: Automotive Body Control Module, Remote Keyless Entry Transmitter, Automotive Sensor Signal Conditioner, Industrial HVAC Controller, Battery-Powered Wireless Sensor Node, Instrument Cluster Sub-Processor.
Automotive Body Control Module
The STM8AL3166TA's AEC-Q100 qualification, -40C to +125C operating range, and 32 KB of Flash make it a strong fit for body control modules (BCMs) that manage door locks, lighting, and seat subsystems. Its ultra-low-power Halt mode draws sub-microamp standby current, allowing BCMs to wake only on LIN-bus or GPIO events, which preserves automotive battery life during parked states. With three 16-bit timers and an RTC, the MCU can schedule periodic polling without CPU intervention. Placed on the BCM main PCB, the device replaces larger 16-bit MCUs in cost-sensitive body domains while retaining automotive-grade robustness specified in the ST family datasheet.
Recommended
Remote Keyless Entry Transmitter
The STM8AL3166TA's ultra-low-power Active-Halt mode and integrated AES-128 hardware accelerator on the L-derivative make it ideal for remote keyless entry (RKE) transmitters that must run for years on a CR2032 coin cell. The 16 MHz STM8 core wakes quickly enough to process button presses and rolling-code encryption within 30 ms, while standby current below 1 uA preserves battery runtime. The 12-bit ADC and two comparators can sample battery voltage and external sensors without external components. Placed as the system MCU between the button matrix and the UHF transmitter, the part enables small form-factor key fob designs with reliable AES-128 encryption.
Recommended
Automotive Sensor Signal Conditioner
The STM8AL3166TA integrates a 12-bit ADC, two comparators, and a DAC on-die, enabling it to condition analog sensor outputs directly without external signal-chain ICs. Its 16 MHz core can oversample at 1 kS/s for noise rejection, and the AEC-Q100 grade allows direct mounting near engine or chassis sensors with full automotive robustness. SPI, I2C, and USART peripherals connect to upstream body controllers via LIN or CAN transceivers. Placed on a wheel-speed or temperature sensor PCB, the part replaces discrete op-amp comparator designs while running from a 3.3 V or 5 V automotive rail.
Recommended
Industrial HVAC Controller
The STM8AL3166TA's wide operating temperature and automotive-grade reliability make it equally at home in industrial HVAC controllers that must run for years on unattended equipment. The 32 KB Flash fits firmware for PID loop control, sensor fusion, and Modbus or LIN communications. Three 16-bit timers drive triac phase-angle control for AC line motors, while the RTC schedules compressor cycling. Placed as the main MCU on an HVAC control board, the device offers an automotive-grade reliability upgrade over consumer-grade 8-bit MCUs.
Recommended
Battery-Powered Wireless Sensor Node
The STM8AL3166TA's sub-microamp Halt mode and integrated RTC make it well-suited to battery-powered wireless sensor nodes that must transmit temperature, humidity, or pressure readings every few minutes over years of unattended operation. The 32 KB Flash holds application code plus a small bootloader, and the 12-bit ADC reads analog sensors without external amplifiers. SPI or I2C connects to sub-GHz transceivers like the S2-LP. Placed between the coin cell and the RF module, the MCU's automotive-grade robustness is a bonus for industrial IoT deployments subject to harsh environments.
Recommended
Instrument Cluster Sub-Processor
The STM8AL3166TA can serve as a sub-processor in instrument cluster designs, handling low-speed inputs like button matrices, turn signals, and door-state sensing, while a higher-end host handles graphics. Its 32 KB Flash is plenty for state-machine logic, and the RTC keeps time-stamped logs even when the host is asleep. AEC-Q100 qualification allows mounting on the same PCB as the cluster graphics MCU. Placed on a small satellite PCB, the device offloads housekeeping tasks from the main cluster controller, improving overall system robustness.
Recommended
Recommended Products Summary
Engineering reference data for STM8AL3166TA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM8AL3166TAY | STM8AL3168TA | STM8AL3164TA | STM8L152R6T6A |
|---|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | 32-LQFP (7x7) | 32-LQFP (7x7) - same | 32-LQFP (7x7) - same | 32-LQFP (7x7) - same | 32-LQFP (6x6) - same family |
| Flash Memory | 32 KB | 32 KB | 64 KB | 16 KB | 32 KB |
| Core Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| Core Architecture | STM8 8-bit | STM8 8-bit | STM8 8-bit | STM8 8-bit | STM8 8-bit |
| Automotive Grade | Yes (AEC-Q100) | Yes (AEC-Q100) | Yes (AEC-Q100) | Yes (AEC-Q100) | No (industrial) |
| Supply Voltage | 1.65 V to 3.6 V | 1.65 V to 3.6 V | 1.65 V to 3.6 V | 1.65 V to 3.6 V | 1.65 V to 3.6 V |
| ADC | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit |
| Unit Price (qty-1000) | USD 2.90 | USD 2.95 | USD 3.20 | USD 2.65 | USD 2.40 |
Key Differentiators
- Automotive-grade AEC-Q100 qualification with same family footprint (vs STM8L152R6T6A)
- Drop-in 64 KB Flash upgrade on identical footprint (vs STM8AL3168TA)
- Lower-cost Flash-reduced variant in same package (vs STM8AL3164TA)
Design Notes
Estimated: at 16 MHz active current of approximately 1 mA/MHz and Halt-mode current below 1 uA, a typical RKE duty cycle of 0.01% wake time keeps average consumption under 5 uA. Place a 100 nF X7R ceramic bypass capacitor within 5 mm of the VDD pin and a 1 uF bulk capacitor on the VCAP pin. Brown-out reset is enabled by default - do not disable it in automotive deployments.
Keep the OSCIN/OSCOUT traces short (under 5 mm) and surrounded by a ground pour to prevent the high-frequency crystal harmonics from coupling into adjacent analog traces. The VCAP pin is the internal regulator stabilization node and requires a low-ESR 1 uF ceramic capacitor placed within 3 mm with short traces. Avoid routing signal traces under the crystal.
Do not assume the STM8AL3166TA is the same as STM8L152R6T6A - the AL suffix is automotive-grade, the L is industrial. While both share the LQFP family, their datasheet electrical characteristics differ slightly in ESD ratings. Also note that the LQFP-32 (7x7) used here is NOT pin-compatible with the smaller LQFP-32 (6x6) used on some STM8L parts - verify the PCB footprint matches before substituting.
Estimated: the LQFP-32 (7x7) package has a theta_JA of approximately 60 C/W on a 2-layer 1-oz PCB. At maximum 16 MHz active power of approximately 30 mW, junction temperature rise is below 2 C above ambient, well within the 125 C automotive limit. For high-ambient under-hood applications, use a 4-layer PCB with thermal vias to reduce theta_JA further.
Compliance Information
AEC-Q100 qualified per STMicroelectronics family documentation. RoHS compliant per ST product page. Halogen-free per ST policy on automotive 8-bit line.
