Drive scheme for ultrasonic transducer pixel readout

A method comprising:

• providing a diode bias signal to a sampling diode coupled with a sampling node;
• providing a receive bias signal to a first electrode;
• initiating transmission of an ultrasonic signal using a piezoelectric ultrasonic transducer having the first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes, the second electrode being coupled with the sampling node, the piezoelectric ultrasonic transducer capable of receiving a reflected portion of the ultrasonic signal and generating a response characteristic based on the reflected portion of the ultrasonic signal;
• controlling the diode bias signal to bias the diode in association with a temporary transition of a mode of operation from a normal mode to a sampling mode, the diode bias signal being driven to a first level corresponding to the normal mode and a second level corresponding to the sampling mode, wherein the first level is a non-zero voltage level that is different from the second level and from a voltage level of the receive bias signal, and wherein the second level is a non-zero voltage level that is different from the first level and from the voltage level of the receive bias signal;
• and
• enabling sampling, during the sampling mode of operation, of an electrical signal at the sampling node.

A non-transitory computer readable medium storing program code to be executed by one or more processors, the program code comprising instructions configured to cause:

• providing a diode bias signal to a sampling diode coupled with a sampling node;
• providing a receive bias signal to a first electrode;
• initiating transmission of an ultrasonic signal using a piezoelectric ultrasonic transducer having the first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes, the second electrode being coupled with the sampling node, the piezoelectric ultrasonic transducer capable of receiving a reflected portion of the ultrasonic signal and generating a response characteristic based on the reflected portion of the ultrasonic signal;
• controlling the diode bias signal to bias the diode in association with a temporary transition of a mode of operation from a normal mode to a sampling mode, the diode bias signal being driven to a first level corresponding to the normal mode and a second level corresponding to the sampling mode, wherein the first level is a non-zero voltage level that is different from the second level and from a voltage level of the receive bias signal, and wherein the second level is a non-zero voltage level that is different from the first level and from the voltage level of the receive bias signal;
• and
• enabling sampling, during the sampling mode of operation, of an electrical signal at the sampling node.

An apparatus comprising:

• transducer means for generating an ultrasonic wave and receiving a reflected portion of the wave, the transducer means having a first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes, the first electrode configured to receive a receive bias signal, the second electrode being coupled with a sampling node;
• diode bias means for at least partially driving an electrical signal at the sampling node, the diode bias means coupled with the sampling node, the diode bias means providing a diode bias signal to a sampling diode at a first level corresponding to a normal mode of operation and a second level corresponding to a sampling mode of operation, wherein the first level is a non-zero voltage level that is different from the second level and from a voltage level of the receive bias signal, and wherein the second level is a non-zero voltage level that is different from the first level and from the voltage level of the receive bias signal;
• and
• reading means for reading the electrical signal, the reading means coupled with the sampling node.