Texas Instruments TXB0108PWR does the voltage translation in between Spark Core's 3.3V logic level and Arduino's 5V logic.

 

Due to the limited number of pin to function combinations, only three analog channels are mapped i.e A0, A1 and A2. Unlike other IO pins, the analog pins are rated at only a max of 3.3V and NOT 5.0V. Please remember NOT to exceed this voltage at anytime.The shield has an onboard voltage regulator and can be powered from 7V to 15V DC. You could also power it via the USB plug on the Spark Core alone but the current would be limited to 500mA.

 

SPECS:

·         Operating voltage: 7 to 15V DC

·         Current consumption: standalone 7mA at 9V DC

·         Voltage translator with auto direction detect: TXB0108PWR

·         Dedicated MOSFET based voltage translator on I2C lines

·         Separate unidirectional quad buffer for driving heavy loads: 74ACT125

·         Diode protection on ADC pins

·         Dimensions: 3.4" x 2.1"

·         Weight: 28 gms