STM8S003K3T6 - 8-bit 16MHz MCU, 8KB Flash | STMicroelectronics
MPN: STM8S003K3T6 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.2 | $1.20 |
| 10 | $1.05 | $10.50 |
| 100 | $0.88 | $88.00 |
| 500 | $0.74 | $370.00 |
| 1,000 | $0.61 | $610.00 |
STM8S003K3T6 Overview
A value-line microcontroller (often called an 8-bit MCU) is a small, low-cost processor optimised for embedded control tasks such as sensor reading, motor actuation, indicator driving, and user-interface handling. Within the broader semiconductor hierarchy, an MCU is a subset of microprocessors (MPU) and is differentiated by integrated Flash, RAM and peripherals on a single die. The STM8S003K3T6 occupies the entry-level value-line of the STM8S family, balancing die size, peripheral set and price for cost-sensitive designs where a 32-bit MCU is unnecessary.
Key features that differentiate the STM8S003K3T6 in its class include 1 KB of RAM, the integrated 10-bit SAR ADC with up to 5 multiplexed channels, the clock security system (CSS) that detects external clock failure and switches to the internal RC oscillator, plus 100 k write/erase cycle endurance on the data EEPROM. Robust I/O design tolerates 5 V injection on adjacent pins, simplifying mixed-voltage interface to legacy 5 V peripherals. The 32-pin LQFP-32 (7x7) footprint provides easy hand-soldering and breadboard prototyping versus fine-pitch QFN options.
Technically, the STM8S003K3T6 is engineered around the proprietary STM8 core with 16-bit index registers and a 20-bit program counter, executing most instructions in 1-2 clock cycles. The integrated voltage regulator and brown-out reset (BOR) circuitry protect the Flash against low-voltage write corruption. The 16 MHz system clock can be sourced from an external crystal, resonator, or the factory-trimmed internal 16 MHz RC oscillator with ±1 % accuracy across the full operating temperature range.
Typical applications include low-cost consumer appliances (rice cookers, washing-machine user interfaces, induction cooktops), battery-powered sensor nodes, LED lighting controllers, simple BLDC/PMSM auxiliary motor drivers (fans, pumps), 5 V industrial control buttons, and Arduino-Nano-compatible hobbyist boards. The wide 2.95-5.5 V supply range and proven STM8 toolchain (STVD, IAR, Cosmic, SDCC) make it a frequent second source for legacy 8051 designs requiring a software refresh.
When designing with the STM8S003K3T6, choose between the internal 16 MHz RC oscillator (saves BOM cost) and an external crystal (better UART baud-rate accuracy). Decouple VDD/VSS with 100 nF ceramic capacitors placed within 3 mm of each supply pin, and reserve the SWIM pin (single-wire debug) for in-circuit programming. For noisy environments, enable the CSS and the window watchdog for IEC 60730 class B compliance.
This page synthesizes distributor pricing, drop-in alternatives and practical design notes not found in the manufacturer datasheet, and is intended as a faster reference than the 31-page ST datasheet for engineers evaluating the part for production.
Drop-in alternatives for STM8S003K3T6 — 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 STM8S003K3T6 (same form factor and footprint) — differing in Data EEPROM, Operating Temperature, Timers, Package, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
STM8S003K3T6C
✅ Drop-In📋 Reference alternative (not in catalog)
STM8S003K3T6CTR
✅ Drop-In📋 Reference alternative (not in catalog)
STM8S105K4T6
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.26 / Unit
View Datasheet →STM8S207K4T6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8S103K3T6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM8S003K3T6 Maximum Ratings & Electrical Characteristics
| Core Architecture | STM8 8-bit |
| Maximum Clock Frequency | 16 MHz |
| Program Memory (Flash) | 8 KB |
| Data EEPROM | 128 bytes |
| RAM | 1 KB |
| Data EEPROM Endurance | 100 k write/erase cycles |
| Supply Voltage (VDD) | 2.95 V to 5.5 V |
| ADC | 10-bit SAR, up to 5 channels |
| Timers | 3 x 16-bit general-purpose |
| Communication Interfaces | 1 x UART, 1 x SPI, 1 x I2C |
| Watchdog | Independent window WDG, separate clock source |
| Clock Security System (CSS) | Yes |
| Brown-Out Reset (BOR) | Yes |
| Operating Temperature | -40 C to +85 C |
| Package | LQFP-32 (7x7 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
STM8S003K3T6 Pin Configuration
| Pin 1 | PD3 — Port D3 GPIO / TIM2_CH3 alternate |
| Pin 2 | PD4 — Port D4 GPIO / SWIM debug data |
| Pin 3 | PD5 — Port D5 GPIO / UART_TX alternate |
| Pin 4 | PD6 — Port D6 GPIO / UART_RX alternate |
| Pin 5 | NRST — Active-low reset input |
| Pin 6 | PA1 — Port A1 GPIO / OSCIN |
| Pin 7 | PA2 — Port A2 GPIO / OSCOUT |
| Pin 8 | VSS — Digital ground |
| Pin 9 | VCAP — 1.8 V regulator decoupling capacitor |
| Pin 10 | VDD — Digital supply 2.95-5.5 V |
| Pin 11 | PB5 — Port B5 GPIO / I2C_SDA alternate |
| Pin 12 | PB4 — Port B4 GPIO / I2C_SCL alternate |
| Pin 13 | PC6 — Port C6 GPIO |
| Pin 14 | PC7 — Port C7 GPIO / SPI_MOSI alternate |
| Pin 15 | PC5 — Port C5 GPIO / SPI_MISO alternate |
| Pin 16 | PC4 — Port C4 GPIO / SPI_SCK alternate |
| Pin 17 | PC3 — Port C3 GPIO / TIM1_CH3 alternate |
| Pin 18 | PC2 — Port C2 GPIO / TIM1_CH2 alternate |
| Pin 19 | PC1 — Port C1 GPIO / ADC_AIN5 alternate |
| Pin 20 | PC0 — Port C0 GPIO / ADC_AIN6 alternate |
| Pin 21 | PD1 — Port D1 GPIO / TIM2_CH1 alternate |
| Pin 22 | PD2 — Port D2 GPIO / TIM2_CH2 alternate |
| Pin 23 | PD0 — Port D0 GPIO / TIM1_BKIN alternate |
| Pin 24 | PB0 — Port B0 GPIO / ADC_AIN0 alternate |
| Pin 25 | PB1 — Port B1 GPIO / ADC_AIN1 alternate |
| Pin 26 | PB2 — Port B2 GPIO / ADC_AIN2 alternate |
| Pin 27 | PB3 — Port B3 GPIO / ADC_AIN3 alternate |
| Pin 28 | PA3 — Port A3 GPIO / TIM2_CH3 alternate |
| Pin 29 | PF4 — Port F4 GPIO |
| Pin 30 | VSS — Digital ground |
| Pin 31 | VDD — Digital supply 2.95-5.5 V |
| Pin 32 | PD7 — Port D7 GPIO / TLI alternate |
Typical Applications
STM8S003K3T6 is suitable for 6 applications: Low-Cost Consumer Appliance Control, Battery-Powered Sensor Node, LED Lighting Controller, Small BLDC / Fan Motor Control, 5 V Industrial Control Button / HMI, Arduino-Nano-Compatible Hobby Board.
Low-Cost Consumer Appliance Control
The STM8S003K3T6 fits small home appliances (rice cookers, microwave user interfaces, washing-machine front panels) where BOM cost and 5 V supply tolerance are decisive. Its 16 MHz STM8 core delivers roughly 16 MIPS, ample for keypad scanning, LED/LCD multiplexing, and relay or triac control loops. The 8 KB Flash and 1 KB RAM accommodate typical appliance state machines without external memory. The integrated 10-bit ADC reads temperature sensors (NTC) and humidity probes, while the UART enables factory calibration via the test pad. Pin-compatible with other STM8S003 family members, the design can migrate to higher-density variants without PCB rework.
Recommended
Battery-Powered Sensor Node
The STM8S003K3T6's wide 2.95-5.5 V supply range suits 3.3 V lithium or 3 x AA alkaline battery packs powering remote sensor nodes. Its 10-bit ADC and I2C interface connect directly to temperature, humidity or motion sensors, while the UART serves a low-power radio module. Window watchdog and clock security system improve IEC 60730 class B compliance for safety-related household devices. Halt and Active-Halt modes drop current to a few microamps, extending battery life to multiple years for duty-cycled sampling. Programming via SWIM allows field firmware updates through a standard 4-pin test connector.
Recommended
LED Lighting Controller
The STM8S003K3T6 is widely used in commercial LED driver boards for PWM dimming, colour-temperature mixing and DMX-style lighting control. The three 16-bit timers provide high-resolution PWM channels driving constant-current LED driver MOSFETs, with 16 MHz core clock yielding 488 Hz PWM frequency at 12-bit resolution. The integrated 10-bit ADC closes the loop on light-level feedback or thermistor-based LED derating. I2C and SPI allow connection to digital temperature sensors and addressable RGB strips. The LQFP-32 (7x7) footprint keeps the MCU off the high-current path, simplifying PCB thermal management.
Recommended
Small BLDC / Fan Motor Control
The STM8S003K3T6 drives small 5 V brushless DC fans and pumps with simple 6-step commutation. Its three timers produce complementary PWM pairs to the gate driver, while the integrated ADC samples back-EMF for sensor-less rotor position. The window watchdog detects stalled rotor conditions, meeting IEC 60335 safety expectations for unattended appliances. UART diagnostics output RPM and fault logs for factory tuning. 5 V GPIO tolerance drives logic-level MOSFETs directly without level shifters. Migration to FOC control is straightforward via the same LQFP-32 footprint stepping up to STM32G0/G4.
Recommended
5 V Industrial Control Button / HMI
Industrial push-buttons, selector switches and human-machine interface panels use the STM8S003K3T6 for rugged 5 V tolerant operation and IEC 61000-4-2 ESD-rated GPIO. The on-chip 10-bit ADC reads potentiometer or selector position, the UART bridges to PLC fieldbuses, and the SPI drives segment displays. The clock security system switches automatically to internal RC if an external crystal fails, preventing MCU lock-up in unmanned panels. Halt-mode wakeup via GPIO keeps quiescent current under 10 uA for battery-backed safety stops. The LQFP-32 (7x7) is hand-solderable, easing field repair.
Recommended
Arduino-Nano-Compatible Hobby Board
The STM8S003K3T6 (and its smaller STM8S003F3 sibling) is the basis for ultra-low-cost Arduino-Nano-compatible boards aimed at hobbyists, education and rapid prototyping. The 16 MHz core and 8 KB Flash fit simple sketches while keeping the board price under USD 2 BOM. The SWIM debug pin allows on-board programming with the ST-LINK/V2, removing the need for a separate ISP header. Native 5 V GPIO drives legacy shields, and the integrated ADC and PWM channels support robotics and sensor experiments. Libraries from the open-source sduino and Arduino_Core_STM8 projects make the part approachable to non-embedded developers.
Recommended
Recommended Products Summary
Engineering reference data for STM8S003K3T6 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM8S003K3T6C | STM8S003K3T6CTR | STM8S105K4T6 | STM8S207K4T6 | STM8S103K3T6 |
|---|---|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | LQFP-32 (7x7) | LQFP-32 (7x7) - same | LQFP-32 (7x7) - same | LQFP-32 (7x7) - same | LQFP-32 (7x7) - same | LQFP-32 (7x7) - same |
| Core | STM8 8-bit | STM8 8-bit | STM8 8-bit | STM8 8-bit | STM8 8-bit | STM8 8-bit |
| Max Clock | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 24 MHz | 16 MHz |
| Flash | 8 KB | 8 KB | 8 KB | 16 KB | 16 KB | 8 KB |
| RAM | 1 KB | 1 KB | 1 KB | 2 KB | 2 KB | 1 KB |
| Data EEPROM | 128 B | 128 B | 128 B | 1 KB | 2 KB | 640 B |
| ADC | 10-bit, 5 ch | 10-bit, 5 ch | 10-bit, 5 ch | 10-bit, 7 ch | 10-bit, 7 ch | 10-bit, 4 ch |
| Product Line | Value-line | Value-line | Value-line | Access-line | Performance-line | Access-line |
Key Differentiators
- Wider supply-voltage range than PIC16F equivalent (vs PIC16F18855-I/PT (LQFP-32 functional equivalent))
- More Flash than basic STM8S001J3M3 (SO-8) option (vs STM8S001J3M3)
- 100 kbyte-cycle true EEPROM endurance (vs Generic 8051 derivative in LQFP-32)
Design Notes
Estimated: with VDD = 5.0 V, VSS = 0 V, all GPIO idle and CPU in Halt mode, the STM8S003K3T6 draws about 5 uA typ. Active mode at 16 MHz with all peripherals on is roughly 4.5 mA. Decouple each VDD/VSS pair with a 100 nF X7R ceramic placed within 3 mm of the pin, plus a single 10 uF bulk cap on the main 5 V rail. The VCAP pin requires a 1 uF X7R to VSS for the internal 1.8 V regulator - never leave VCAP floating.
Route the SWIM pin (PD4 on this LQFP-32) to a 4-pin test pad (VDD, GND, SWIM, NRST) for in-circuit programming. Place a 100 nF on NRST with a 10 kohm pull-up to VDD. Keep the crystal traces short and symmetric if you choose an external HSE; for cost-down designs the internal 16 MHz RC oscillator eliminates the crystal entirely. Provide a guard ring around the VCAP node to minimise digital switching noise coupling into the regulator.
Do not exceed the 5.5 V absolute-maximum VDD rating even on transients - add a TVS such as SMAJ5.0A on the supply rail if long wires are exposed. The CSS (Clock Security System) only works when the option byte is configured - enable it during production programming, not in development, or the MCU may halt after a momentary crystal glitch. The 128-byte EEPROM is rated for 100 k cycles only when VDD > 2.95 V during the write - writes below BOR threshold are silently dropped.
Compliance Information
RoHS and REACH compliant per STMicroelectronics material declarations. Halogen-free package per ST product page. Not AEC-Q100 qualified - automotive designs should select STM8AF series. Conflict-mineral declarations published on ST corporate-responsibility site.
