Single-ended trans-impedance amplifier (TIA) for ultrasound device
An ultrasound circuit comprising a single-ended trans-impedance amplifier (TIA) is described, The TIA is coupled to an ultrasonic transducer to amplify an electrical signal generated by the ultrasonic transducer in response to receiving an ultrasound signal. The TEA is followed by further processing circuitry configured to filter, amplify, and digitize the signal produced by the TIA.
1. An ultrasound apparatus, comprising:
an ultrasonic transducer; and
a single-ended trans-impedance amplifier (TIA) having an input terminal coupled to the ultrasonic transducer and configured to receive and amplify an analog electrical signal from the ultrasonic transducer;
wherein:
the ultrasonic transducer is a first ultrasonic transducer and the single-ended TIA is a first single-ended TIA;
the ultrasound apparatus comprises a plurality of ultrasonic transducers including the first ultrasonic transducer and a plurality of respective single-ended TIAs coupled to the respective ultrasonic transducers, the plurality of respective single-ended TIAs including the first single-ended TIA; and
the ultrasound apparatus further comprises:
an averaging circuit having an input coupled to the plurality of respective single-ended TIAs;
a filter and a time gain compensation (TGC) circuit, the filter being coupled electrically between the averaging circuit and the TGC circuit;
an analog-to-digital converter (ADC) coupled to an output terminal of the TGC circuit; and
an ADC driver coupled to the ADC and configured to drive the ADC, the ADC driver comprising a folded cascode super source follower.
2. The ultrasound apparatus of claim 1 , further comprising a switch coupled between the first ultrasonic transducer and the input terminal of the first single-ended TIA.
3. The ultrasound apparatus of claim 1 , wherein the plurality of respective single-ended TIAs are configured to exhibit a first voltage swing, and wherein the TGC circuit is configured to exhibit a second voltage swing greater than the first voltage swing.
4. The ultrasound apparatus of claim 3 , wherein the second voltage swign is between 1.5 and five times greater than the first voltage swing.
5. The ultrasound apparatus of claim 3 , wherein the averaging circuit and filter are configured to exhibit a voltage swing less than the second voltage swing.
6. The ultrasound apparatus of claim 5 , wherein the averaging circuit and filter are configured to exhibit the first voltage swing.
7. The ultrasound apparatus of claim 3 , wherein the plurality of ultrasonic transducers, plurality of respective single-ended TIAs, filter, and TGC circuit are formed on a single substrate.
8. The ultrasound apparatus of claim 7 , wherein the plurality of ultrasonic transducers are capacitive micromachined ultrasonic transducers (CMUTs).
9. The ultrasound apparatus of claim 1 , wherein the first single-ended TIA comprises a common source circuit coupled to a source follower.
10. An ultrasound circuit, comprising:
an ultrasonic transducer; and
a plurality of analog processing stages coupled to an output of the ultrasonic transducer and including one analog processing stage configured to exhibit a greater voltage swing than other analog processing stages of the plurality of analog processing stages;
wherein the one analog processing stage configured to exhibit the greater voltage swing is a time gain compensation (TGC) circuit.
11. The ultrasound circuit of claim 10 , wherein the TGC circuit is the last analog processing stage before an analog-to-digital converter (ADC).
12. The ultrasound circuit of claim 10 , wherein the one analog processing stage configured to exhibit a greater voltage swing is the last analog processing stage before an analog-to-digital converter (ADC).
13. The ultrasound circuit of claim 10 , wherein the plurality of analog processing stages comprises a single-ended trans-impedance amplifier.
14. The ultrasound circuit of claim 10 , further comprising an analog-to-digital converter (ADC) and an ADC driver coupled to a last analog processing stage of the plurality of analog processing stages, the ADC driver comprising a folded cascode super source follower.
15. An ultrasound circuit, comprising:
an ultrasonic transducer;
an amplifier having an input terminal coupled to the ultrasonic transducer; and
a time gain compensation (TGC) circuit, wherein the amplifier is electrically coupled between the ultrasonic transducer and the TGC circuit, and
wherein the amplifier is configured to exhibit a first voltage swing and the TGC circuit is configured to exhibit a second voltage swing greater than the first voltage swing.
16. The ultrasound circuit of claim 15 , wherein the amplifier is a single-ended trans-impedance amplifier (TIA).
17. The ultrasound circuit of claim 16 , wherein the single-ended TIA comprises a common source circuit coupled to a source follower.
18. The ultrasound circuit of claim 15 , further comprising an analog-to-digital converter (ADC) driver coupled electrically downstream of the TGC, the ADC driver comprising a folded cascode super source follower.