STM8AL3166UAY - 8-Bit 16MHz 32KB Flash Auto MCU | STMicroelectronics
MPN: STM8AL3166UAY ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.72 | $37.20 |
| 100 | $3.18 | $318.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.42 | $2,420.00 |
STM8AL3166UAY Overview
An automotive 8-bit ultra-low-power MCU is a microcontroller designed for the harsh electrical and thermal environment of vehicles, emphasizing low quiescent current, extended voltage range, and AEC-Q100 reliability qualification. The STM8AL sits in the broader 8-bit microcontroller hierarchy (8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC) and is optimized for direct sensor interfacing, LIN/CAN connectivity, and standby current budgets measured in microamperes. Compared with 32-bit Cortex-M alternatives, STM8AL devices offer smaller code footprint, deterministic interrupt latency, and substantially lower cost per node for body-electronics applications.
Key features of the STM8AL3166UAY include: 32KB single-voltage Flash with in-application programming, 1KB true EEPROM for parameter storage, hardware RTC with calendar and alarm, two USARTs (one LIN-capable), two SPIs, one I2C, a 12-bit ADC, a 12-bit DAC, two ultra-low-power comparators, and a 4-channel DMA. The integrated LIN 2.1 compliant USART simplifies in-vehicle networking nodes. The BxCAN interface is not present on this density device, but USART-LIN combined with the RTC and EEPROM provides a complete body-controller-on-a-chip.
The device uses the STM8 Harvard-architecture core with a 3-stage pipeline and 16-bit instructions for code density. Its embedded voltage regulator supports single-supply operation down to 1.65V, enabling direct connection to a 3.3V or 5V rail. Run-mode current is approximately 200 uA/MHz, while Halt with RTC consumes only 0.9 uA typical, allowing automotive electronic control units to meet strict quiescent-current budgets (typically <100 uA) on the battery rail when the ignition is off.
Typical applications include automotive body control modules, LIN slave nodes for seat and mirror control, sensor interface ECUs for temperature and pressure, lighting controllers, RKE receivers, dashboard clusters, and HVAC control panels. The on-chip 12-bit ADC and DAC pair support analog sensor signal chains without external converters. The 32-VFQFPN (5x5 mm) package footprint with exposed pad gives good thermal performance and suits space-constrained under-hood and behind-cluster layouts.
When designing with this device, ensure the exposed pad is soldered to a contiguous ground copper pour for thermal dissipation and signal integrity. The EEPROM write endurance is 300k cycles minimum at 85C - budget write frequency accordingly for non-volatile parameter storage. The LIN master/slave mode requires an external LIN transceiver such as the TLE7259-3GE for physical bus compliance.
This page synthesizes distributor pricing, drop-in alternatives, and comparison data not found on the manufacturer product page alone - enabling faster sourcing decisions.
Drop-in alternatives for STM8AL3166UAY — 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 STM8AL3166UAY (same form factor and footprint) — differing in Communication Interfaces, Package, Core Architecture, ADC, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
STM8AL3166UAX
✅ Drop-In📋 Reference alternative (not in catalog)
STM8AL3166TC
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →STM8AL3146UAY
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8AL3136UAY
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8L152R6T6A
✅ Drop-In📋 Reference alternative (not in catalog)
STM32L412CBU6
✅ Drop-In✓ In Stock
$2.74 / Unit
View Datasheet →STM8AL3166UAY Maximum Ratings & Electrical Characteristics
| Product Family | STM8AL automotive ultra-low-power 8-bit |
| Core Architecture | STM8 8-bit Harvard |
| Maximum Clock Frequency | 16 MHz |
| Program Flash Memory | 32 KB (32K x 8) |
| SRAM | 2 KB |
| Data EEPROM (true) | 1 KB |
| Supply Voltage Range | 1.65 V to 5.5 V |
| Package | 32-VFQFPN (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40 C to +125 C (automotive grade 1) |
| AEC-Q100 Qualification | Qualified |
| Communication Interfaces | 2x USART (LIN 2.1), 2x SPI, 1x I2C |
| ADC / DAC | 12-bit ADC, 12-bit DAC, 2x comparators |
| RTC | Yes, with calendar and alarm |
| DMA Channels | 4 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
STM8AL3166UAY Pin Configuration
| Pin 1 | PA3 — Port A bit 3 (GPIO/TIM2_CH3) |
| Pin 2 | PA2 — Port A bit 2 (GPIO/TIM2_CH2) |
| Pin 3 | PA1 — Port A bit 1 (GPIO/TIM2_CH1) |
| Pin 4 | PA0 — Port A bit 0 (GPIO) |
| Pin 5 | NRST — Active-low reset input |
| Pin 6 | OSCIN — External clock input / crystal oscillator pin |
| Pin 7 | OSCOUT — Crystal oscillator output |
| Pin 8 | VSS — Digital ground |
| Pin 9 | VCAP — Voltage regulator stabilization cap |
| Pin 10 | VDD — Digital supply voltage (1.65V to 5.5V) |
| Pin 11 | PB7 — Port B bit 7 (I2C_SDA) |
| Pin 12 | PB6 — Port B bit 6 (I2C_SCL) |
| Pin 13 | PB5 — Port B bit 5 (SPI_NSS/USART_CK) |
| Pin 14 | PB4 — Port B bit 4 (SPI_MOSI/USART_TX) |
| Pin 15 | PB3 — Port B bit 3 (SPI_MISO/USART_RX) |
| Pin 16 | PB2 — Port B bit 2 (SPI_SCK) |
| Pin 17 | PB1 — Port B bit 1 (USART_LIN_TX) |
| Pin 18 | PB0 — Port B bit 0 (USART_LIN_RX) |
| Pin 19 | PC7 — Port C bit 7 (GPIO/MCO) |
| Pin 20 | PC6 — Port C bit 6 (GPIO/TIM1_CH1) |
| Pin 21 | PC5 — Port C bit 5 (GPIO/TIM1_CH2) |
| Pin 22 | PC4 — Port C bit 4 (GPIO/TIM1_CH3) |
| Pin 23 | PC3 — Port C bit 3 (GPIO/TIM1_CH4) |
| Pin 24 | PC2 — Port C bit 2 (GPIO) |
| Pin 25 | PC1 — Port C bit 1 (GPIO) |
| Pin 26 | PD0 — Port D bit 0 (ADC_IN0/COMP1_INP) |
| Pin 27 | PD1 — Port D bit 1 (ADC_IN1/COMP1_INN) |
| Pin 28 | PD2 — Port D bit 2 (ADC_IN2) |
| Pin 29 | PD3 — Port D bit 3 (ADC_IN3) |
| Pin 30 | PD4 — Port D bit 4 (ADC_IN4) |
| Pin 31 | PD5 — Port D bit 5 (ADC_IN5/DAC_OUT) |
| Pin 32 | PD6 — Port D bit 6 (ADC_IN6/COMP2_INP) |
| Pin 33 | EP — Exposed thermal pad - connect to VSS for thermal relief |
Typical Applications
STM8AL3166UAY is suitable for 6 applications: Automotive Body Control Module (BCM), LIN Sensor / Actuator Slave Node, Automotive Lighting Controller, HVAC Control Panel ECU, Remote Keyless Entry (RKE) Receiver, Instrument Cluster Sub-Display Controller.
Automotive Body Control Module (BCM)
The STM8AL3166UAY fits body control modules because it integrates a LIN-capable USART, RTC, and 1KB true EEPROM for non-volatile parameter storage at automotive temperature grades. Its AEC-Q100 grade 1 qualification (-40 C to +125 C) and 32-VFQFPN 5x5 mm exposed-pad package give a small footprint with reliable thermal performance behind the dashboard. The 32KB Flash holds BCM application code for door-lock, lighting, and mirror control, while 2KB SRAM supports LIN message buffers and debounce tables. Estimated run-mode current of 200 uA/MHz and Halt-mode current of 0.9 uA typical allow the BCM to meet strict 100 uA quiescent-current budgets on the battery rail when the ignition is off.
Recommended
LIN Sensor / Actuator Slave Node
The STM8AL3166UAY is ideal for LIN sensor slaves (temperature, pressure, position) because its LIN 2.1 hardware USART handles break-symbol generation/detection and automatic baud-rate synchronization without firmware overhead. The 12-bit ADC (up to 1 Msps on some channels) and 12-bit DAC pair provide analog signal conditioning in one chip, removing external converters. The 1KB true EEPROM with 300k write cycles supports in-field calibration storage. Halt-mode current of 0.9 uA typical lets battery-fed LIN nodes sleep for months while maintaining wake-on-LIN capability.
Recommended
Automotive Lighting Controller
The STM8AL3166UAY drives LED lighting modules via its PWM-capable timers and 12-bit DAC for dimming curves. AEC-Q100 grade 1 qualification allows placement near the headlamp assembly where ambient temperature reaches +125 C. The 32KB Flash accommodates turn-indicator sequencing, fade tables, and CAN/LIN message handling, while the 2KB SRAM buffers LED-state commands. The exposed-pad 32-VFQFPN (5x5 mm) delivers good heat dissipation for the device's own consumption (~3 mA active, 0.9 uA halt), keeping junction temperature rise modest even under continuous dashboard operation.
Recommended
HVAC Control Panel ECU
The STM8AL3166UAY powers HVAC climate-control panels with its 12-bit ADC reading temperature sensors (NTC), potentiometers, and fan-speed feedback. The two comparators handle over-temperature shutdown without waking the CPU, while the RTC maintains time-of-day for scheduled climate profiles. AEC-Q100 grade 1 qualification and 1.65V to 5.5V supply tolerance allow direct connection to the 5V or 3.3V body bus. The 32-VFQFPN (5x5 mm) exposed-pad footprint fits the tight dashboard PCB constraint typical of HVAC modules.
Recommended
Remote Keyless Entry (RKE) Receiver
The STM8AL3166UAY's ultra-low Halt-mode current of 0.9 uA typical makes it suitable for always-on RKE receivers that must listen on the RF front-end for months on a coin cell or vehicle battery. The on-chip RTC wakes the device on a schedule, and the hardware LIN/USART can pass authentication commands to the BCM. The 32KB Flash stores rolling-code algorithms, while 1KB true EEPROM retains pairing keys across battery swaps. AEC-Q100 grade 1 qualification ensures operation across automotive temperature extremes.
Recommended
Instrument Cluster Sub-Display Controller
The STM8AL3166UAY drives secondary instrument-cluster displays (gear-position indicators, warning lamps) via SPI to a main MCU and I2C to local sensors. The 12-bit DAC generates analog gauge pointer drives, while the PWM timers control LED backlight brightness. AEC-Q100 grade 1 qualification and 32-VFQFPN 5x5 mm footprint fit the dense cluster PCB behind the speedometer. The 32KB Flash holds indicator logic, and the 1KB EEPROM retains user preferences (units, brightness) across power cycles.
Recommended
Recommended Products Summary
Engineering reference data for STM8AL3166UAY — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM8AL3166UAX | STM8AL3166TC | STM8L152R6T6A | STM32L412CBU6 |
|---|---|---|---|---|---|
| Package | 32-VFQFPN (5x5 mm) | 32-VFQFPN (5x5 mm) - same | 32-LQFP - same pin count | 32-LQFP - same pin count | 32-UFQFPN (5x5 mm) - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Core | STM8 8-bit @ 16 MHz | STM8 8-bit @ 16 MHz | STM8L 8-bit @ 16 MHz | STM8L 8-bit @ 32 MHz | Cortex-M0+ 32-bit @ 80 MHz |
| Flash | 32 KB | 32 KB | 32 KB | 32 KB | 128 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 40 KB |
| Supply Voltage | 1.65V to 5.5V | 1.65V to 5.5V | 1.65V to 3.6V | 1.65V to 3.6V | 1.71V to 3.6V |
| AEC-Q100 | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 2) | Yes (Grade 2) |
| LIN 2.1 USART | Yes | Yes | Yes | Yes | Yes (USART + LPUART) |
| Operating Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +105 C | -40 C to +125 C |
Key Differentiators
- AEC-Q100 Grade 1 qualification at full -40 to +125 C automotive range (vs STM8L152R6T6A)
- Wider supply voltage range (1.65V to 5.5V) (vs STM32L412CBU6)
- True 1KB hardware EEPROM with 300k write endurance (vs STM32L412CBU6)
- 32-VFQFPN (5x5 mm) compact exposed-pad footprint (vs STM8AL3166TC)
Design Notes
Solder the exposed thermal pad (pin 33) of the 32-VFQFPN (5x5) to a contiguous VSS copper pour with at least 16 thermal vias to the inner ground plane. The pad reduces junction-to-ambient thermal resistance (estimated theta_JA approximately 50 C/W on a 2-layer JEDEC EIA/JESD51 1-oz board) and improves mechanical reliability under automotive thermal-cycling. For under-hood placements exceeding +105 C ambient, increase copper area or add thermal relief at the GND pour.
Decouple VDD (pin 10) with a 100 nF X7R ceramic placed within 3 mm of the pin, plus a 4.7 uF bulk tantalum or ceramic on the same node. Place a 1 uF ceramic on VCAP (pin 9) - the internal LDO requires this for regulator stability. Estimated: at 16 MHz active, core current draws approximately 3.2 mA, so the 100 nF must recharge the supply within 5 ns of any load transient to prevent VDD droop.
Route the crystal traces (OSCIN/OSCOUT, pins 6/7) as short, symmetric loops with a ground guard ring on both sides. Keep them at least 3 mm away from switching signals such as SPI SCK and PWM outputs to avoid injecting jitter. Add a 4.7-ohm series resistor on each OSCIN/OSCOUT trace if the crystal is more than 5 mm from the MCU to dampen overdrive.
The LIN USART (PB0/PB1) requires an external transceiver such as the TLE7259-3GE for bus compliance - connecting directly to the LIN bus will fail EMC and DC parametric tests. Also budget EEPROM write endurance at 300k cycles minimum at 85 C; do not exceed this in wear-leveling designs. The I2C peripheral needs external 4.7k pull-ups on PB6/PB7 even in 5V mode, as the internal pull-ups are weak.
Compliance Information
AEC-Q100 Grade 1 qualified for automotive applications per STMicroelectronics product page. Lead-free and RoHS compliant. REACH-VERIFY ecosystem compliance confirmed by ST product documentation. Choose STM32L052C8T6 if Grade 2 (-40 to +105 C) is acceptable.
