STM32F103CBT6 Maple Mini 32-Bit ARM Development Board

Description
The Maple Mini is the breadboard friendly Maple development board featuring a smaller, 48-pin STM32 with the same speed and memory as the original Maple. Smaller than a stick of gum, the Maple Mini sports 120 KB Flash memory, 34 GPIOs and 20 KB of SRAM. The Maple is a 32-bit ARM development board that is coupled with the Maple IDE.
If your current Arduino-based project is pushing against the performance limits of the ATmega, porting it over to Maple may be the fastest and easiest way to continue developing your project without starting from scratch.
Power regulation on the Maple is provided by two low dropout linear voltage regulators. 
The part is the MCP1703 from Microchip, in the SOT-23A package. 
One of the regulators supplies power to the digital voltage plane; the other supplies power to the analog voltage plane.
If you are planning to draw a lot of current from the Maple board, it is necessary to provide input power as close to 3.3V as possible. 
Powering the microcontroller circuitry and LEDs on the board alone takes approximately 30mA, so if you are powering the board with 12V that leaves only 10mA (at best) available for powering any user circuitry. 

Features
CPU: STM32F103CBT6, a 32-bit ARM Cortex M3 microprocessor
Clock Speed: 72 MHz
Flash: 128 KB
SRAM: 20 KB
34 Digital I/ pins (GPIOs)
12 PWM pins at 16-bit resolution
9 analog input (ADC) pins at 12-bit resolution
2 SPI peripherals
2 I2C peripherals
7 Channels of Direct Memory Access (DMA) (dma.h)
3 USART (serial port) peripherals
1 advanced and 3 general-purpose timers
Dedicated USB port for programming and communications
JTAG
Supplies up to 500 mA at 3.3 V, with separate 250 mA digital and analog regulators for
Low-Noise analog performance
Open source, four-layer design
Support for low power, sleep, and standby modes (<500 µA)
Operating Voltage: 3.3 V
Input Voltage (recommended): 3 V ” 12 V
Size: 20mm x 7mm

Note:
1- The silkscreen on the Maple Mini suggests it will accept an input voltage up to 16 V. We recommend applying no greater than 12 V, and potentially even lower depending upon the current draw requirements of the application. Please see Power Regulation on the Maple Mini for more information.
2- Attempting to draw more than 10mA runs the risk of shorting out the power regulators and bricking your board.