Differential ultrasonic transducer element for ultrasound devices
Aspects of the technology described herein relate to ultrasound circuits that employ a differential ultrasonic transducer element, such as a differential micromachined ultrasonic transducer (MUT) element. The differential ultrasonic transducer element may be coupled to an integrated circuit that is configured to operate the differential ultrasonic transducer element in one or more modes of operation, such as a differential receive mode, a differential transmit mode, a single-ended receive mode, and a single-ended transmit mode.
1. An ultrasound device, comprising:
a differential capacitive micromachined ultrasonic transducer (CMUT) element operable in each of a plurality of modes including:
a differential receive mode,
a differential transmit mode,
a single-ended receive mode, and
a single-ended transmit mode; and
an integrated circuit, coupled to the differential CMUT element, that:
selects a mode from the plurality of modes; and
operates the differential CMUT element in the selected mode.
2. The ultrasound device of claim 1 , wherein the integrated circuit is configured to operate the differential CMUT element in the differential receive mode and the differential transmit mode.
3. The ultrasound device of claim 1 , wherein
the differential CMUT element is integrated into an ultrasonic transducer array, and
the integrated circuit and the ultrasonic transducer array are disposed on a single semiconductor die.
4. The ultrasound device of claim 1 , wherein
the differential CMUT element comprises:
a first CMUT that is configured to be biased with a first bias voltage; and
a second CMUT that is configured to be biased with a second bias voltage.
5. The ultrasound device of claim 4 , wherein
when operating the differential CMUT element in the differential transmit mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have opposite polarities; and
drives the first CMUT and the second CMUT with pulse signals having opposite polarities.
6. The ultrasound device of claim 4 , wherein
the ultrasound device further comprises one or more receive circuits, and
when operating the differential CMUT element in the differential receive mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have opposite polarities; and
couples the differential CMUT element to the one or more receive circuits.
7. The ultrasound device of claim 4 , wherein
when operating the differential CMUT element in the single-ended transmit mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have a same polarity; and
drives the first CMUT and the second CMUT with pulse signals having a same polarity.
8. The ultrasound device of claim 4 , wherein
the ultrasound device further comprises one or more receive circuits, and
when operating the differential CMUT element in the
single-ended receive mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have a same polarity; and
couples the differential CMUT element to the one or more receive circuits.
9. The ultrasound device of claim 1 , wherein
the differential CMUT element comprises a first CMUT and a second CMUT,
the ultrasound device further comprises a pulser circuit that drives the first CMUT with a first pulse signal and drives the second CMUT with a second pulse signal, and
the first pulse signal is phase-shifted relative to the second pulse signal.
10. The ultrasound device of claim 1 , wherein
the differential CMUT element comprises a first CMUT and a second CMUT, and
the ultrasound device further comprises:
a receive circuit comprising a first terminal and a second terminal; and
a switch matrix that selectively couples the first CMUT and the second CMUT to the first terminal or the second terminal of the receive circuit.
11. An ultrasound device, comprising:
a differential micromachined ultrasonic transducer (MUT) element; and
an integrated circuit coupled to the differential MUT element and configured to operate the differential MUT element in at least one of a differential receive mode and a differential transmit mode and at least one of a single-ended receive mode and a single-ended transmit mode.
12. The ultrasound device of claim 11 , wherein the integrated circuit is configured to operate the differential MUT element in the differential receive mode and the differential transmit mode.
13. The ultrasound device of claim 11 , wherein
the differential MUT element is integrated into an ultrasonic transducer array, and
the integrated circuit and the ultrasonic transducer array are disposed on a single semiconductor die.
14. The ultrasound device of claim 11 , wherein
the differential MUT element comprises:
a first MUT that is configured to be biased with a first bias voltage; and
a second MUT that is configured to be biased with a second bias voltage.
15. The ultrasound device of claim 14 , wherein
when operating the differential MUT element in the differential transmit mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have opposite polarities; and
drives the first MUT and the second MUT with pulse signals having opposite polarities.
16. The ultrasound device of claim 14 , wherein
the ultrasound device further comprises one or more receive circuits, and
when operating the differential MUT element in the differential receive mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have opposite polarities; and
couples the differential MUT element to the one or more receive circuits.
17. The ultrasound device of claim 14 , wherein
when operating the differential MUT element in the single-ended transmit mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have a same polarity; and
drives the first MUT and the second MUT with pulse signals having a same polarity.
18. The ultrasound device of claim 14 , wherein
the ultrasound device further comprises one or more receive circuits, and
when operating the differential MUT element in the single-ended receive mode, the integrated circuit:
causes the first bias voltage and the second bias voltage to have a same polarity; and
couples the differential MUT element to the one or more receive circuits.
19. The ultrasound device of claim 11 , wherein
the differential MUT element comprises a first MUT and a second MUT,
the ultrasound device further comprises a pulser circuit that drives the first MUT with a first pulse signal and drives the second MUT with a second pulse signal, and
the first pulse signal is phase-shifted relative to the second pulse signal.
20. The ultrasound device of claim 11 , wherein
the differential MUT element comprises a first MUT and a second MUT, and
the ultrasound device further comprises:
a receive circuit comprising a first terminal and a second terminal; and
a switch matrix that selectively couples the first MUT and the second MUT to the first terminal or the second terminal of the receive circuit.