Multi-level pulser and related apparatus and methods

Abstract

Apparatus and methods are provided directed to a device, including at least one ultrasonic transducer, a multi-level pulser coupled to the at least one ultrasonic transducer; the multi-level pulser including a plurality of input terminals configured to receive respective input voltages, an output terminal configured to provide an output voltage, and a signal path between a first input terminal and the output terminal including a first transistor having a first conductivity type coupled to a first diode and, in parallel, a second transistor having a second conductivity type coupled to a second diode.

What is claimed is: 
     
         1 - 20 . (canceled) 
     
     
         21 . An ultrasound device, comprising:
 an ultrasonic transducer;   a pulser coupled to the ultrasonic transducer and configured to output a pulse to the ultrasonic transducer, the pulser comprising:
 a first transistor comprising a first gate terminal, a first source terminal, and a first drain terminal, wherein:
 the first source terminal is coupled to a first reference voltage; and 
 the first drain terminal is coupled, through a first diode, to the ultrasonic transducer; and 
 
   control circuitry integrated on a single semiconductor substrate together with the pulser and configured to:
 control the pulser to change a voltage of the pulse to approximately the first reference voltage by outputting a first control signal to the first gate terminal of the first transistor such that a conductive channel is created between the first source terminal and the first drain terminal of the first transistor. 
   
     
     
         22 . The ultrasound device of  claim 21 , wherein the first transistor is a p-channel metal-oxide-semiconductor (pMOS) transistor, the first control signal comprises the first reference voltage combined with a voltage value, and the control circuitry is configured to control the pulser to decrease the voltage of the pulse. 
     
     
         23 . The ultrasound device of  claim 21 , wherein the first transistor is an n-channel metal-oxide-semiconductor (nMOS) transistor, the first control signal comprises the first reference voltage combined with a voltage value, and the control circuitry is configured to control the pulser to decrease the voltage of the pulse. 
     
     
         24 . The ultrasound device of  claim 21 , wherein the pulser further comprises:
 a second transistor comprising a second gate terminal, a second source terminal, and a second drain terminal, wherein:
 the second source terminal is coupled to a second reference voltage; and 
 the second drain terminal is coupled, through a second diode, to the ultrasonic transducer; and wherein: 
   the control circuitry is further configured to:
 control the pulser to change the voltage of the pulse to approximately the second reference voltage by outputting a second control signal to the second gate terminal of the second transistor such that a conductive channel is created between the second source terminal and the second drain terminal of the first transistor. 
   
     
     
         25 . The ultrasound device of  claim 24 , wherein the second transistor is a pMOS transistor, the second control signal comprises the second reference voltage combined with a voltage value, and the control circuitry is configured to control the pulser to decrease the voltage of the pulse. 
     
     
         26 . The ultrasound device of  claim 24 , wherein the second transistor is an nMOS transistor, the second control signal comprises the second reference voltage combined with a voltage value, and the control circuitry is configured to control the pulser to decrease the voltage of the pulse. 
     
     
         27 . The ultrasound device of  claim 21 , wherein the pulser is configured to generate N-level pulses and comprises 2N−2 transistors. 
     
     
         28 . The ultrasound device of  claim 21 , wherein the pulser is configured to generate N-level pulses and comprises 2N−4 diodes. 
     
     
         29 . The ultrasound device of  claim 21 , wherein the pulser is configured to generate N-level pulses and comprises N−1 pMOS transistors and N−1 nMOS transistors. 
     
     
         30 . The ultrasound device of  claim 21 , wherein the first reference voltage is between approximately −300V and 300V. 
     
     
         31 . The ultrasound device of  claim 21 , wherein the first reference voltage is between approximately −200V and 200V. 
     
     
         32 . The ultrasound device of  claim 21 , wherein the ultrasonic transducer comprises a capacitive micromachined ultrasonic transducer (CMUT). 
     
     
         33 . The ultrasound device of  claim 21 , wherein the ultrasonic transducer comprises a piezoelectric micromachined ultrasonic transducer (PMUT). 
     
     
         34 . An ultrasound device, comprising:
 an ultrasonic transducer;   a multi-level pulser coupled to the ultrasonic transducer and configured to output an N-level pulse to the ultrasonic transducer, wherein:
 the pulser comprises 2N−2 transistors; 
 each of a plurality of the 2N−2 transistors comprises a respective gate terminal, a respective source terminal, and a respective drain terminal; 
 a first transistor of the plurality of the 2N−2 transistors has at least one inverter coupled to the respective gate terminal; 
 the respective source terminal is coupled to a respective reference voltage; and 
 the respective drain terminal is coupled, through a respective diode, to the ultrasonic transducer. 
   
     
     
         35 . The ultrasound device of  claim 34 , wherein the pulser comprises 2N−4 diodes. 
     
     
         36 . The ultrasound device of  claim 34 , wherein the pulser comprises N−1 pMOS transistors and N−1 nMOS transistors. 
     
     
         37 . The ultrasound device of  claim 34 , wherein the respective reference voltage is between approximately −300V and 300V. 
     
     
         38 . The ultrasound device of  claim 34 , wherein the respective reference voltage is between approximately −200V and 200V. 
     
     
         39 . The ultrasound device of  claim 34 , wherein the ultrasonic transducer comprises a capacitive micromachined ultrasonic transducer (CMUT). 
     
     
         40 . The ultrasound device of  claim 34 , wherein the ultrasonic transducer comprises a piezoelectric micromachined ultrasonic transducer (PMUT).