Patent ID: 8721550

Claim:
An ultrasound transmitter, comprising: a high side driver and a low side driver, wherein each of the high side driver and the low side driver comprising an N- type field effect transistor (FET) serially coupled to a P-type FET, where, the N-type FET and P-type FET of each of the high side driver and the low side driver configured to switch current to an output of the driver in response to a driver switching control signal; buffer drivers comprising inputs and outputs where inputs are coupled to the bias network and outputs are coupled to both the high side and the low side drivers; a bias network that substantially equalizes the voltage drop across the N-type FET and the P-type FET of the high side and the low side drivers; wherein the bias network further comprises: a first, second, third and fourth resistance coupled in series between a high side driver input and a low side driver input on an input side of the ultrasound transmitter, wherein the high side buffer is coupled between the first resistance and the second resistance and the gate of the high side P-type FET; wherein the low side buffer is coupled between the third resistance and the fourth resistance and the gate of the low side N-type FET; and wherein a node between the second resistor and the third resistor is coupled to a node between the high side buffer and the low side buffer, and the high side buffer and low side buffer are coupled to ground; wherein current flow through the bias network becomes substantially zero when the first and second drivers are disabled; and wherein activation of the high side driver drives the ultrasound transmitter output to a first voltage and activation of the low side driver drives the ultrasound transmitter output to a second voltage, said activations producing a high voltage ultrasonic drive signal at the ultrasound transmitter output preserving a symmetry of the high-side and the low-side.