STMicroelectronics STM32F101R6T6A, STM32F1 series, 32-bit ARM Cortex-M3 MCU, 36 MHz, 32 KB Flash, 6 KB SRAM, 51 I/O, 64-LQFP, -40 to 85°C.
| Parameter | Value |
|---|---|
| Series | STM32F1 |
| Mounting | Surface Mount |
| Oscillator type | Internal |
| Program memory type | FLASH |
| Voltage - supply (Vcc (Vdd)) | 2V ~ 3.6V |
| Operating temperature | -40°C ~ 85°C (TA) |
| Speed | 36MHz |
| Package | Tray |
| RAM size | 6K x 8 |
| Core size | 32-Bit Single-Core |
| Peripherals | DMA, PDR, POR, PVD, PWM, Temp Sensor, WDT |
| Connectivity | I²C, IrDA, LINbus, SPI, UART/USART |
| Number of i (O) | 51 |
| Core processor | ARM® Cortex®-M3 |
| Case | 64-LQFP |
| Data converters | A/D 16x12b |
| Program memory size | 32KB (32K x 8) |
The 36 MHz core speed is about half what the STM32F103 offers, but for a typical control loop — reading a 12-bit ADC, running a PID, updating a PWM duty cycle — it leaves plenty of headroom. The 6 KB SRAM is tight: budget about 2 KB for stack and interrupt vectors, leaving 4 KB for data buffers.
The 51 I/O give you plenty of GPIO for parallel displays, keypads, or sensor arrays.
The STM32F101R6T6A is pin-compatible with the STM32F103 in the same 64-LQFP footprint, but it runs at 36 MHz instead of 72 MHz and lacks USB and CAN interfaces. If your firmware fits in 32 KB Flash and 6 KB SRAM and you do not need USB or CAN, it is a drop-in replacement for cost reduction. Otherwise, stay with the STM32F103 or step up to the STM32F105.
The STM32L151CBU6A is a Cortex-M3 alternative with similar peripherals (I²C, SPI, UART, 12-bit ADC) but adds USB, a DAC, and capacitive sensing, and runs at 32 MHz on a lower 1.8 V supply. It is not a pin-compatible drop-in — it comes in a different package (UFQFPN-48) — but it is a functional alternative if you need lower power or USB.