Patent ID: 8715192

Claim:
An ultrasound transmitter, comprising: a high side driver and a low side driver, wherein each of the a high side driver and a 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 the first input to the second input on an input side of the ultrasound transmitter, and coupled between the gate of the N-type FET of the high side driver and the gate of the P-type FET of the low side driver on an output side of the ultrasound transmitter, wherein a first buffer is coupled between the first resistance and the second resistance and the gate of the high side P-type FET; wherein a second 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 driver and the low side driver; 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.