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STMicroelectronics STM8S903F3M3 — Microcontrollers & Processors (MCU / MPU / DSP)

ST STM8S903F3M3 8-bit MCU, 16MHz, 8KB Flash, SOIC-20

MPNSTM8S903F3M3
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STMicroelectronics STM8S series 8-bit MCU, STM8 core, 16MHz, 8KB Flash, 1K x 8 RAM, 640 x 8 EEPROM, 20-SOIC package, -40°C to 125°C.

$1.2915Ref. price · indicative, final on quote
STMicroelectronics STM8S903F3M3 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STM8S903F3M3 specifications
ParameterValue
SeriesSTM8S
MountingSurface Mount
Oscillator typeInternal
Program memory typeFLASH
Voltage - supply (Vcc (Vdd))2.95V ~ 5.5V
Operating temperature-40°C ~ 125°C (TA)
Speed16MHz
PackageTube
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)16
Core processorSTM8
Case20-SOIC (0.295\", 7.50mm Width)
Data convertersA/D 5x10b
Program memory size8KB (8K x 8)

Product details

What this 8-bit MCU delivers

The STM8S903F3M3 is an 8-bit MCU from STMicroelectronics built around the STM8 core, clocked at 16 MHz. It carries 8 KB of Flash program memory, 1 KB of RAM, and 640 bytes of EEPROM — enough for a single control loop, sensor interface, or simple communication bridge in an embedded system.

Peripheral set and I/O

Sixteen I/O lines are available on the 20-pin SOIC package, plus a 5-channel 10-bit ADC for analog inputs.

Supply and oscillator

The STM8S903F3M3 is designated end-of-life hot (EOL hot). It is no longer recommended for new designs.

Frequently asked questions

What is STM8S903F3M3's listed speed?

The core runs at 16 MHz, which is typical for an 8-bit MCU handling sensor polling, communication protocols, or simple control loops without heavy number-crunching.