MD0101 is a four channel, high voltage, current limiting protection device. It is designed to protect a low noise receiver from the high voltage transmit pulses in ultrasound applications and is commonly referred to as a T/R (transmit and receive) switch. Each channel has three terminals; Tx, Rx, and RGND. The analog switch terminals are Tx and Rx. Rx has integrated clamping diodes to RGND to protect the receiver against high voltages. Voltages greater than ±0.6V will start forward biasing the clamp diodes to RGND. The MD0101 can be considered as a normally closed switch with a typical switch resistance of 15O, allowing small signals to pass. Once the voltage drop across the switch exceeds a nominal value of ±1.0V, the device will start to turn off. In the off state, the MD0101 can withstand up to ±100V across its terminals. A small amount of current, 200µA, is allowed to flow through. The MD0101 is not limited to just ultrasound applications. It can also be used for resettable fuses to protect power lines, output short circuit protection, and data acquisition. The MD0101 is available in an 18-Lead, 5x5mm DFN package as a four channel device for high density requirements.

• Up to ±100V input voltage protection
• Low on resistance - 15Ω typical
• Integrated clamp diodes
• Fast switching speed
• Four electrically isolated channels
• No external supplies needed