STM32F103C8T6 Datasheet, Pinout, Specs, and LQFP-48 Package Guide

STM32F103C8T6 is one of the most widely recognized microcontrollers in the STM32F1 series. It is used in embedded control systems, development boards, sensor interfaces, industrial modules, communication devices, and general-purpose MCU projects. Many engineers also know it from low-cost “Blue Pill” development boards, but the part number STM32F103C8T6 refers to the microcontroller IC itself, not the complete board.

This guide provides a practical overview of the STM32F103C8T6 datasheet, pinout structure, major specifications, LQFP-48 package details, peripheral groups, and sourcing considerations. It is written for engineers, purchasing teams, students, and hardware designers who need a quick but reliable summary before selecting or buying the part.

For price, stock, lead time, or sourcing support, visit the STM32F103C8T6 product page .

What Is STM32F103C8T6?

STM32F103C8T6 is a 32-bit microcontroller from STMicroelectronics’ STM32F103 family. It is based on the ARM Cortex-M3 core and is commonly listed with a maximum CPU frequency of 72 MHz, 64 KB Flash memory, 20 KB SRAM, and an LQFP-48 package.

The STM32F103 family is part of the STM32 mainstream performance line. These devices are designed for applications that need a balance of processing performance, peripheral integration, low cost, and mature ecosystem support. The STM32F103C8T6 is especially popular because it offers a useful set of timers, communication interfaces, ADC channels, GPIO pins, and debugging support in a compact 48-pin package.

The full part number can be read as follows:

For production use, always confirm the exact ordering information, package, marking, and packing type from the supplier or official datasheet.

STM32F103C8T6 Datasheet Overview

The STM32F103C8T6 datasheet provides detailed information about ordering codes, electrical characteristics, package dimensions, pin definitions, peripheral availability, memory organization, and device limitations. For a quick design review, the most important sections to check are:

1. Device description
2. This section explains the STM32F103 medium-density performance line, CPU core, memory, buses, and peripheral architecture.
3. Ordering information
4. This helps confirm whether the exact orderable part number matches the required package, memory size, and temperature range.
5. Pinouts and pin descriptions
6. This is critical when designing a PCB footprint or mapping GPIO and alternate functions.
7. Electrical characteristics
8. This section includes supply voltage, current consumption, I/O characteristics, ADC parameters, clock requirements, and operating conditions.
9. Package information
10. This section provides LQFP-48 mechanical dimensions, footprint guidance, and package drawings.
11. Peripheral characteristics
12. Designers should review the details for ADC, timers, communication interfaces, USB, CAN, SPI, I2C, USART, and other functions used in the project.

A datasheet should not be treated as only a PDF download. For engineering and procurement, it is the primary reference for confirming whether the device fits the circuit, firmware, package, and production process.

Key Specifications of STM32F103C8T6

The following table summarizes commonly referenced STM32F103C8T6 specifications. Always verify final design values against the official datasheet before production.

This specification mix is one reason STM32F103C8T6 remains popular. It is more capable than many simple 8-bit MCUs while still being cost-effective and widely supported by tools, libraries, and community examples.

STM32F103C8T6 Pinout Overview

STM32F103C8T6 uses an LQFP-48 package. The pinout includes power pins, reset and boot pins, oscillator pins, debug pins, GPIO ports, analog inputs, timer outputs, and communication interface pins.

Instead of thinking of the pinout as a random list of 48 pins, it is better to understand it by functional groups.

1. Power and Ground Pins

The STM32F103C8T6 includes digital and analog power pins. These pins must be connected carefully for stable operation.

Common power-related pins include:

1. VDD: digital power supply
2. VSS: digital ground
3. VDDA: analog power supply
4. VSSA: analog ground
5. VBAT: backup power supply for backup domain, depending on design use

For PCB design, proper decoupling capacitors should be placed close to the power pins. VDDA and VSSA should be handled carefully if the ADC is used, because analog noise can affect measurement accuracy.

2. Reset and Boot Pins

Important system control pins include:

1. NRST: external reset input
2. BOOT0: boot mode selection pin

BOOT0 is especially important during programming and startup. Depending on the BOOT0 and boot configuration, the MCU can boot from main Flash memory, system memory, or SRAM. For normal product operation, BOOT0 is usually fixed to the required logic level through a resistor.

3. Oscillator Pins

The device supports clock input through oscillator-related pins. External crystal or resonator circuits are commonly used when accurate timing is needed.

Typical oscillator-related pins include:

1. OSC_IN
2. OSC_OUT
3. LSE oscillator pins for low-speed external clock use, depending on the selected configuration

A correct clock design is important for USB, communication timing, real-time functions, and stable MCU operation.

4. GPIO Ports

STM32F103C8T6 provides GPIO pins mainly across Port A, Port B, and selected Port C / Port D pins depending on package configuration. These pins can be used as digital inputs, digital outputs, alternate function pins, analog inputs, timer channels, or communication interface pins.

Common GPIO groups include:

1. PA0 to PA15
2. PB0 to PB15
3. PC13 to PC15
4. PD0 and PD1 in oscillator-related functions depending on configuration

Not every function is available on every pin at the same time. Many pins are multiplexed, which means one physical pin may support different functions such as GPIO, USART, SPI, I2C, timer output, ADC input, or debug function. Designers must check the alternate function mapping before finalizing the schematic.

5. Debug Pins

STM32F103C8T6 supports common STM32 debugging and programming methods. SWD is often preferred because it requires fewer pins than full JTAG.

Common debug-related functions include:

1. SWDIO
2. SWCLK
3. JTAG-related pins depending on configuration

If you need more GPIO pins, some debug pins can be remapped or disabled after development, but this should be done carefully. Keeping SWD access available is strongly recommended for production programming, firmware debugging, and troubleshooting.

6. Analog Input Pins

The MCU includes ADC functionality, and several GPIO pins can also serve as analog input channels. These pins are useful for reading sensors, voltage dividers, potentiometers, analog signals, and other measurement inputs.

When using ADC inputs, pay attention to:

1. Input voltage range
2. Source impedance
3. Analog ground layout
4. Decoupling
5. Sampling time
6. Noise from digital switching or power circuits

For accurate measurement, the analog layout and reference supply quality matter as much as the MCU specification.

7. Communication Interface Pins

STM32F103C8T6 supports several common embedded communication interfaces, depending on configuration and pin mapping.

Common interface types include:

1. USART / UART for serial communication
2. SPI for sensors, displays, memory, and peripheral ICs
3. I2C for sensors, EEPROMs, PMICs, and low-speed devices
4. USB for device communication
5. CAN for industrial and automotive-related communication designs

The exact pin mapping depends on the alternate function configuration. Designers should confirm whether the chosen pins conflict with debugging, oscillator, boot, or other required functions.

STM32F103C8T6 LQFP-48 Package

STM32F103C8T6 is commonly supplied in an LQFP-48 package. LQFP stands for Low-profile Quad Flat Package. It is a surface-mount package with gull-wing leads on all four sides.

The LQFP-48 package is popular because it is compact but still easier to inspect and rework than many leadless packages. For prototypes and small production runs, LQFP is often more convenient than BGA or QFN packages.

When using STM32F103C8T6 in a PCB design, check:

1. LQFP-48 footprint dimensions
2. Pin pitch
3. Land pattern
4. Solder mask clearance
5. Assembly process capability
6. Pin 1 orientation
7. Package height
8. Reflow soldering profile
9. Moisture sensitivity handling, if applicable

For sourcing, also confirm whether the part is supplied in tray, cut tape, tape-and-reel, or other packaging formats. The package code and the packing method are not the same thing. For example, STM32F103C8T6 and STM32F103C8T6TR may refer to the same core IC specification, while the “TR” version usually indicates tape-and-reel packaging for automated assembly.

STM32F103C8T6 vs STM32F103C8T6TR

STM32F103C8T6 and STM32F103C8T6TR are often compared because buyers see both part numbers in distributor listings.

In most design contexts, the main difference is not the MCU core, memory, or package. The main difference is the ordering and packaging format.

For engineering design, the two are generally treated as the same functional microcontroller if the full manufacturer specifications match. For purchasing and production, however, the packaging format matters. If your assembly line requires tape-and-reel, confirm the TR version or equivalent packaging with the supplier before ordering.

Is STM32F103C8T6 the Same as Blue Pill?

No. STM32F103C8T6 is the microcontroller IC. “Blue Pill” usually refers to a low-cost development board built around an STM32F103C8T6 or similar STM32F103-series microcontroller.

A Blue Pill board usually includes:

1. STM32F103-series MCU
2. Crystal oscillator
3. Voltage regulator
4. USB connector
5. Reset and boot buttons or jumpers
6. Header pins
7. Supporting passive components

This distinction is important for both engineers and buyers. If you are building a product, you usually need the STM32F103C8T6 IC or an equivalent MCU, not the complete Blue Pill board. If you are learning, prototyping, or testing firmware, a Blue Pill board may be useful as a development platform.

STM32F103C8T6 Memory and Firmware Considerations

STM32F103C8T6 is commonly associated with 64 KB Flash and 20 KB SRAM. This is enough for many embedded applications, but not for every firmware project.

Before selecting STM32F103C8T6, check:

1. Final compiled firmware size
2. Bootloader requirements
3. Communication stack size
4. RTOS usage
5. Peripheral driver libraries
6. Debug and diagnostic code
7. Future firmware expansion

If your firmware is close to the memory limit, a related STM32F103 part with larger Flash may be safer. For example, STM32F103CBT6 is commonly associated with a larger Flash size while remaining in a similar family and package class. However, replacement decisions should always be verified against the datasheet, pinout, memory map, and firmware requirements.

Common Applications of STM32F103C8T6

STM32F103C8T6 is used in a wide range of embedded applications. Common examples include:

1. Industrial control modules
2. Motor control systems
3. Sensor interface boards
4. IoT devices
5. USB-connected devices
6. CAN communication modules
7. Test and measurement equipment
8. Battery-powered embedded products
9. Educational development boards
10. Robotics controllers
11. Small automation devices
12. Communication gateways
13. Display and user-interface controllers

Its popularity comes from a combination of performance, cost, package accessibility, peripheral set, and ecosystem support.

Design Notes for STM32F103C8T6

When designing with STM32F103C8T6, pay attention to the following points.

Power Supply

Use a stable supply within the allowed operating range. Add proper decoupling capacitors near each VDD pin. If analog functions are used, pay attention to VDDA filtering and analog ground layout.

Clock Source

Select the clock source based on application requirements. USB and communication timing may require accurate clock design. Check crystal load capacitors, PCB routing, and oscillator startup conditions.

Boot Configuration

BOOT0 should not be left floating. Set the boot configuration according to your programming and production requirements.

Debug Access

Keep SWD access available whenever possible. It is helpful for programming, debugging, firmware recovery, and production testing.

Pin Multiplexing

Check alternate function conflicts early. A pin used for SPI, USART, ADC, or timer output may conflict with another required function.

ADC Layout

If using analog inputs, separate noisy digital traces from sensitive analog signals. Use proper grounding and filtering.

USB and CAN Design

If using USB or CAN, review the reference design requirements, external components, impedance considerations, and transceiver requirements where applicable.

Sourcing Notes for STM32F103C8T6

Because STM32F103C8T6 is a popular MCU, it is widely searched and frequently sourced. However, buyers should still verify important procurement details before placing an order.

Check the following:

1. Manufacturer: STMicroelectronics
2. Full part number: STM32F103C8T6
3. Package: LQFP-48
4. Packaging type: tray, cut tape, tape-and-reel, or other supplier packaging
5. Quantity
6. Date code
7. RoHS status
8. Lifecycle status
9. Lead time
10. Traceability
11. Label and marking
12. Moisture handling requirements
13. Whether STM32F103C8T6TR is required for tape-and-reel production

If the part is being used as a replacement, do not rely only on family similarity. Compare pinout, package, memory size, clock configuration, peripheral usage, electrical ratings, and firmware compatibility.

For stock, quotation, and sourcing support, visit the STM32F103C8T6 product page .

STM32F103C8T6 vs Similar Parts

The STM32F103 family includes many related part numbers. Some may look very similar but differ in Flash size, package, pin count, temperature range, or packaging format.

For replacement or cross-reference use, always verify:

1. Flash size
2. SRAM size
3. Package
4. Pinout
5. Peripheral availability
6. Electrical characteristics
7. Firmware compatibility
8. Availability and lifecycle status

A similar STM32F103 part is not automatically a drop-in replacement.

FAQ

Is STM32F103C8T6 still available?

STM32F103C8T6 is still commonly listed by major electronic component distributors and sourcing channels. However, actual availability depends on market demand, regional inventory, allocation, and packaging type. For purchasing, confirm current stock, lead time, date code, and traceability before ordering.

What is the package of STM32F103C8T6?

STM32F103C8T6 is commonly supplied in an LQFP-48 surface-mount package. Designers should confirm the package drawing and footprint requirements in the official datasheet before PCB layout.

What is the difference between STM32F103C8T6 and STM32F103C8T6TR?

The main difference is usually packaging format. STM32F103C8T6TR commonly indicates tape-and-reel packaging, while STM32F103C8T6 may be listed as a base part number or supplied in different distributor packaging formats. The core MCU specification should be verified from the supplier and official ordering information.

Is STM32F103C8T6 the same as Blue Pill?

No. STM32F103C8T6 is the microcontroller IC. Blue Pill is a development board that often uses an STM32F103C8T6 or similar STM32F103-series MCU, along with additional components such as crystal, regulator, USB connector, headers, and boot/reset circuitry.

Can I use STM32F103C8T6 as a replacement for STM32F103CBT6?

Not automatically. STM32F103C8T6 and STM32F103CBT6 are from the same STM32F103 family, but STM32F103CBT6 is commonly associated with larger Flash memory. Before replacing one with the other, check firmware size, pinout, package, memory requirements, peripheral usage, and electrical specifications.

Does STM32F103C8T6 support USB?

The STM32F103C8 device line includes USB functionality, but the final design must follow proper clock, schematic, PCB, and firmware requirements. Always check the official datasheet and reference design notes when implementing USB.

What is the maximum clock frequency of STM32F103C8T6?

STM32F103C8T6 is commonly listed with a maximum CPU frequency of up to 72 MHz. The actual system clock configuration depends on oscillator selection, PLL settings, firmware configuration, and design requirements.

How much Flash and SRAM does STM32F103C8T6 have?

STM32F103C8T6 is commonly listed with 64 KB Flash memory and 20 KB SRAM. If your firmware is large or uses a bootloader, RTOS, communication stack, or complex libraries, check memory usage carefully before finalizing the part.

What should I check before buying STM32F103C8T6?

Check the full part number, manufacturer, package, packaging type, quantity, date code, RoHS status, lead time, lifecycle status, supplier traceability, and whether you need STM32F103C8T6 or STM32F103C8T6TR.

Where can I buy STM32F103C8T6?

STM32F103C8T6 can be sourced from electronic component distributors and qualified sourcing suppliers. For current price, stock, lead time, and bulk order support, visit the STM32F103C8T6 product page .

Conclusion

STM32F103C8T6 remains a popular 32-bit ARM Cortex-M3 microcontroller for embedded control, industrial modules, development boards, sensor systems, USB devices, CAN communication, and general-purpose MCU designs. Its 72 MHz performance, 64 KB Flash, 20 KB SRAM, LQFP-48 package, and mature STM32 ecosystem make it a practical choice for many projects.

For design work, review the official datasheet carefully, especially the pinout, electrical characteristics, clock configuration, package dimensions, and peripheral mapping. For purchasing, confirm the full part number, packaging type, availability, date code, and traceability before ordering.

For sourcing support, stock confirmation, or quotation requests, visit the STM32F103C8T6 product page .