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STMicroelectronics STM8S103K3T6CTR — Microcontrollers & Processors (MCU / MPU / DSP)

STM8S103K3T6CTR 8-bit MCU, 16 MHz, 8 KB Flash, 32-LQFP

MPNSTM8S103K3T6CTR
Active

STMicroelectronics STM8S103K3T6CTR, 8-bit STM8 core MCU, 16 MHz, 8 KB Flash, 1K x 8 RAM, 640 x 8 EEPROM, 2.95 V to 5.5 V, 28 I/O, 32-LQFP, -40°C to 85°C.

$2.2500Ref. price · indicative, final on quote
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STM8S103K3T6CTR specifications
ParameterValue
SeriesSTM8S
MountingSurface Mount
Oscillator typeInternal
Program memory typeFLASH
Voltage - supply (Vcc (Vdd))2.95V ~ 5.5V
Operating temperature-40°C ~ 85°C (TA)
Speed16MHz
PackageTape & Reel (TR) Cut Tape (CT)
RAM size1K x 8
Core size8-Bit
EEPROM size640 x 8
PeripheralsBrown-out Detect/Reset, POR, PWM, WDT
ConnectivityI²C, IrDA, LINbus, SPI, UART/USART
Number of i (O)28
Core processorSTM8
Case32-LQFP
Data convertersA/D 4x10b
Program memory size8KB (8K x 8)

Product details

What this 8-bit MCU brings to a control board

At 16 MHz the STM8 core executes most instructions in one or two clock cycles, so the effective throughput is closer to 16 MIPS for simple register-to-register moves. That is enough headroom for a 10 kHz PID loop with sensor read and PWM update, or for bit-banging a custom serial protocol at 1 Mbps. The internal oscillator trims to ±1% accuracy over temperature, which saves an external crystal in non-critical timing applications.

Memory sizing for firmware and data logging

8 KB of Flash holds a moderate application — think a bootloader plus a state-machine control loop with a few hundred lines of C. The 1 KB SRAM limits buffering; a UART receive ring buffer of 256 bytes plus a 128-byte sensor data array leaves about 640 bytes for stack and variables. The 640 bytes of EEPROM are useful for calibration constants, node ID, or fault logs that survive power loss. If the firmware grows beyond 8 KB, look at the STM8S105 or STM8S207 family members with larger Flash and RAM.

The 32-LQFP package (7x7 mm) is hand-solderable and inspectable, which helps during prototype rework or low-volume production. The wide supply range also helps ride through brown-out conditions common in industrial power rails.

Listed as Active by STMicroelectronics, so there is no imminent EOL risk for new designs.

Frequently asked questions

What is the closest pin-compatible alternative to STM8S103K3T6CTR in this family?

Within the STM8S103 series, the K3 variant is the mid-density option. The STM8S103F3 (20-pin TSSOP) and STM8S103K3 (32-LQFP) share the same core and peripheral set but differ in pin count and package. For a drop-in 32-LQFP replacement with more memory, the STM8S105K6 offers 32 KB Flash and 2 KB RAM in the same footprint.

Is STM8S103K3T6CTR RoHS compliant?

The T6 suffix in the order code indicates a RoHS-compliant, lead-free finish. The part is listed as RoHS compliant per ST's standard product declarations.