The Supertex MD1811 is a high speed, quad MOSFET driver designed to drive high voltage P/N-channel MOSFETs for medical ultrasound applications and other applications requiring a high output current for a capacitive load. The high-speed input stage of the MD1811 can operate from a 1.2 to 5.0 volt logic interface with an optimum operating input signal range of 1.8 to 3.3 volts. An adaptive threshold circuit is used to set the level translator switch threshold to the average of the input logic 0 and logic 1 levels. The input logic levels may be ground referenced, even though the driver is putting out bipolar signals. The level translator uses a proprietary circuit, which provides DC coupling together with high-speed operation.