STM8S103K3T6C - 16MHz 8KB 8-Bit MCU | STMicroelectronics
MPN: STM8S103K3T6C ✓ ActiveSTM8S103K3T6C Overview
An 8-bit microcontroller is a programmable semiconductor that executes instructions from a fixed-width instruction set and uses embedded Flash, RAM, and peripherals to control a product. Within the broader hierarchy, this STM8S device belongs to the microcontroller, embedded processor, and semiconductor categories. It is intended for applications that require economical local control, mixed analog and digital measurement, and standard serial connectivity without a high-performance processor.
The principal features of the STM8S103K3T6C include 16 MHz maximum clock operation, 8 KB of Flash memory, 640 bytes of EEPROM, 28 I/O lines, and four 10-bit ADC channels. Its integrated communications peripherals support UART, SPI, and I2C, while three timers provide timing, input capture, output compare, or basic PWM resources. The 2.95 V to 5.5 V operating range supports common 3.3 V and 5 V embedded systems.
The STM8S access-line architecture combines an 8-bit CPU with integrated analog and serial peripherals on a single package. This integration reduces the component count for embedded control boards by placing analog conversion, nonvolatile data storage, and communication interfaces beside the processor. Flash retains firmware after power removal, while true data EEPROM supports parameter storage that can be updated independently of the program area.
Typical uses include compact industrial controllers, sensor-interface modules, appliance controls, communication adapters, motor and relay-control boards, and cost-sensitive consumer products. The UART is useful for host diagnostics, the SPI interface supports faster peripheral expansion, and the I2C interface accommodates sensors and serial EEPROMs. The ADC enables analog voltage measurement when the application requires 10-bit resolution.
PCB design should preserve clean grounding, short analog-signal paths, and appropriate decoupling near the device. Confirm the exact pin assignments, alternate-function routing, clock configuration, and analog-input limits in the manufacturer datasheet before layout release. Software designers should also account for the limited 8 KB program area when organizing drivers, communications routines, and application logic.
This product page combines manufacturer specifications, package information, sourcing guidance, same-footprint alternatives, comparison parameters, and practical implementation notes. It helps engineers evaluate the STM8S103K3T6C against related 32-pin LQFP devices while preserving attention to memory capacity, peripheral availability, and package-level replacement risks.
Drop-in alternatives for STM8S103K3T6C — 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 STM8S103K3T6C (same form factor and footprint) — differing in ADC Resolution, Flash Program Memory, Operating Temperature Range, Serial Interfaces, Supply Voltage Range.
STM8S105K4T6C
✅ Drop-InContact for price
View Datasheet →STM8S903K3T6C
✅ Drop-InContact for price
View Datasheet →STM8S003K3T6CTR
✅ Drop-In📋 Reference alternative (not in catalog)
STM8S103K3T6C Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit microcontroller |
| Product Series | STM8S access line |
| Maximum Clock Speed | 16 MHz |
| Flash Program Memory | 8 KB (8K x 8) |
| Data EEPROM | 640 x 8 bits |
| ADC Resolution | 10 bits |
| ADC Channel Count | 4 channels |
| Timer Count | 3 timers |
| Serial Interfaces | UART, SPI, and I2C |
| I/O Port Count | 28 I/O lines |
| Supply Voltage Range | 2.95 V to 5.5 V |
| Operating Temperature Range | -40 °C to +85 °C |
| Package Type | 32-pin LQFP |
| Mounting Style | Surface mount |
| Core Processor | STM8 8-bit processor |
| Program Memory Type | Flash |
| Lifecycle Status | Active |
| RoHS Compliance | RoHS3 compliant |
| REACH Compliance | Unknown |
STM8S103K3T6C 32-pin lqfp Pin Configuration Guide
Pin configuration for STM8S103K3T6C (32-pin lqfp package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for STM8S103K3T6C.
Refer to the datasheet for full pin configuration.
Typical Applications
STM8S103K3T6C is suitable for 6 applications: Compact Industrial Sensor Interface, Appliance Control Board, Communication Protocol Converter, Cost-Sensitive Consumer Controller, Motor and Relay Control, Programmable Data Logger.
Compact Industrial Sensor Interface
The STM8S103K3T6C is well suited to a compact sensor interface because it combines a four-channel 10-bit ADC with a 16 MHz 8-bit core and 28 I/O lines. A controller can sample analog inputs, apply filtering or threshold logic, and expose measurements through UART or SPI without relying on an external converter. Its 2.95 V to 5.5 V operating range supports both 3.3 V and 5 V industrial boards, while 8 KB of Flash accommodates focused firmware. Keep analog traces short, separate from switching nodes, and verify the datasheet requirements for analog pins and reference voltage.
Recommended
Appliance Control Board
For appliances, the STM8S103K3T6C can coordinate buttons, indicators, relays, and a small number of analog inputs in one 32-pin LQFP device. Three timers support repetitive timing tasks, while UART provides a path for configuration or diagnostics, and the 10-bit ADC can monitor a sensor or control signal. The 8 KB Flash limit favors compact, well-structured firmware rather than large graphical interfaces. Validate timing behavior at the intended supply voltage and account for inductive loads, surge events, and grounding outside the microcontroller package.
Recommended
Communication Protocol Converter
The STM8S103K3T6C can serve as a small protocol-conversion node because it provides UART, SPI, and I2C interfaces alongside a 16 MHz processor. Firmware can translate messages between a host serial port and an SPI sensor or I2C peripheral while local timers support periodic sampling. Its true data EEPROM can retain configuration values, and the 8 KB Flash program area is adequate for narrowly defined converters. For production designs, verify pin remapping, peripheral clock setup, bus timing, and firmware interrupt requirements against the STM8S103 family documentation.
Recommended
Cost-Sensitive Consumer Controller
The STM8S103K3T6C supports cost-sensitive consumer products where a low-power 8-bit controller, local analog measurement, and serial connectivity are sufficient. A product such as a small accessory, controller, or configurable display product can use the four-channel 10-bit ADC for simple sensing and UART for configuration. The 2.95 V to 5.5 V supply range accommodates common system rails, while the 32-pin LQFP provides more interface options than a minimal controller package. Final selection should consider standby behavior, code size, production programming, and the required operating-temperature grade.
Recommended
Motor and Relay Control
The STM8S103K3T6C can implement basic motor, solenoid, or relay sequencing where timing precision and communication outweigh high-performance control requirements. Its three timers can organize pulse, capture, or compare functions, and its 28 I/O lines provide room for control outputs and status inputs. The ADC can monitor a feedback voltage when suitable analog circuitry is added. Designers should keep motor-current paths away from sensitive traces, use appropriate driver and protection components, and confirm timer output behavior at the intended 2.95 V to 5.5 V operating range.
Recommended
Programmable Data Logger
A small data logger can use the STM8S103K3T6C to acquire periodic sensor readings through its four-channel 10-bit ADC and store configuration or records in its 640 x 8-bit true data EEPROM. The UART can transfer logs to a host, and timers can establish fixed acquisition intervals. The 8 KB Flash limit requires a focused firmware design, while EEPROM write endurance must be respected for frequently changing records. Determine the required logging rate and retention duration before choosing this device, and follow the datasheet limits for supply voltage, write cycles, and ADC operation.
Recommended
Recommended Products Summary
Engineering reference data for STM8S103K3T6C — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM8S105K4T6C | STM8S903K3T6C | STM8S003K3T6CTR |
|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | 32-pin LQFP | 32-pin LQFP | 32-pin LQFP | 32-pin LQFP |
| Product Family | STM8S103 access line | STM8S105 | STM8S903 | STM8S003 |
| Flash Program Memory | 8 KB (8K x 8) | 32 KB | 8 KB | 8 KB |
Key Differentiators
- Provides true data EEPROM alongside Flash (vs STM8S003K3T6CTR)
- Combines three timer blocks with a four-channel 10-bit ADC (vs STM8S903K3T6C)
- Uses only 8 KB of Flash for a focused embedded footprint (vs STM8S105K4T6C)
Design Notes
Place the device's supply decoupling capacitors directly beside the appropriate power and ground pins, using the capacitance and placement guidance in the STM8S103 family datasheet. Route the 16 MHz clock circuit away from ADC inputs and switching edges. Confirm that every used alternate-function pin is mapped correctly in the 32-pin LQFP footprint, because GPIO, timer, UART, SPI, I2C, and analog functions can share physical pins.
Keep analog inputs short and treat the ADC reference as a precision node. Place any required reference or filtering components close to the controller, avoid routing ADC traces parallel to high-current switching paths, and provide a quiet ground reference. The four-channel 10-bit ADC is adequate for many sensor readings, but measurement accuracy still depends on source impedance, reference quality, acquisition time, and the PCB return path.
Design the 2.95 V to 5.5 V supply rail so it remains within operating limits during startup, load changes, and external-interface activity. Apply the manufacturer’s recommended capacitor network and voltage tolerances. In battery-powered equipment, calculate the average and peak current required by the 16 MHz core, ADC, timers, and communications, then confirm that the power source can maintain the chosen rail without excessive droop.
Do not assume that a 32-pin LQFP alternative is a drop-in replacement solely because its footprint and memory capacity look similar. Check alternate-function assignments, supply limits, ADC channels, timer resources, serial peripherals, EEPROM behavior, reset pins, clock pins, and interrupt mappings. Firmware should also be rebuilt and tested for the selected alternative because peripheral behavior and register mappings can differ between STM8 subfamilies.
Compliance Information
The component listing identifies RoHS3 compliance. REACH, AEC-Q100 qualification, lead-free status, halogen-free status, and conflict-minerals status are not established by the available product information.