Time gain compensation circuit and related apparatus and methods
An ultrasound device, including a profile generator, an encoder configured to receive a profile signal from the profile generator, and an attenuator configured to receive a signal representing an output of an ultrasound sensor and coupled to the encoder to receive a control signal from the encoder, the attenuator including a plurality of attenuator stages, the attenuator configured to produce an output signal that is an attenuated version of the input signal.
1. An ultrasound device, comprising:
an ultrasound sensor configured to produce an ultrasound sensor output signal; and
a time-gain compensation circuit including an attenuator coupled to the ultrasound sensor and comprising a plurality of attenuation stages, the attenuator configured to:
receive an input signal representing the ultrasound sensor output signal, and
produce an attenuator output signal that is an attenuated version of the input signal.
2. The ultrasound device of claim 1 , wherein at least two of the plurality of attenuation stages comprises one or more fixed resistors.
3. The ultrasound device of claim 2 , wherein the one or more fixed resistors are digitally enabled.
4. The ultrasound device of claim 2 , where the one or more fixed resistors of each of the at least two of the plurality of attenuation stages are connected in series or parallel with a switch.
5. The ultrasound device of claim 4 , wherein:
the attenuator further comprises a shift register comprising a plurality of flip-flops; and
each flip-flop of the plurality of flip-flops is configured to output a digital signal to a respective switch of a respective attenuation stage of the at least two of the plurality of attenuation stages to cause the respective switch to open or close.
6. The ultrasound device of claim 5 , wherein the attenuator is configured to receive:
a first control signal controlling when shifting of values in the shift register occurs; and
a second control signal controlling a direction of shifting of values in the shift register.
7. The ultrasound device of claim 1 , further comprising:
a profile generator; and
an encoder configured to receive a profile signal from the profile generator;
wherein the attenuator is configured to receive a control signal from the encoder.
8. The ultrasound device of claim 1 , wherein the time-gain compensation circuit further includes a fixed gain amplifier having a gain greater than 0 dB and configured to receive the attenuator output signal from the attenuator and to amplify the attenuator output signal.
9. The ultrasound device of claim 8 , wherein the fixed gain amplifier has a gain between approximately 1 dB and 100 dB.
10. The ultrasound device of claim 8 , wherein the fixed gain amplifier has a gain between approximately 3 dB and 30 dB.
11. The ultrasound device of claim 8 , wherein the fixed gain amplifier has a gain between approximately 5 dB and 20 dB.
12. The ultrasound device of claim 8 , wherein the attenuator has an attenuation between approximately 1 dB and 100 dB.
13. The ultrasound device of claim 8 , wherein the attenuator has an attenuation between approximately 3 dB and 30 dB.
14. The ultrasound device of claim 8 , wherein the attenuator has an attenuation between approximately 5 dB and 20 dB.
15. The ultrasound device of claim 8 , wherein the attenuator and the fixed gain amplifier are configured to perform time-gain compensation on the input signal.