ULTRASOUND TRANSMITTER

• US 20100113936A1
• Filed: 10/30/2008
• Published: 05/06/2010
• Est. Priority Date: 10/30/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Loloee, Arash, Koen, Myron J., Oguzman, Ismail H.
• Granted Patent: US 8,721,550 B2
• Time in Patent Office: Days
• US Class Current: 600/459
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: B06B 1/0215 for generating pulses, e.g. bursts of oscillations, envelopes

Abstract

A system and method for providing a high voltage ultrasonic drive signal from an ultrasound transmitter are disclosed herein. An ultrasound transmitter includes a first driver and a bias network. The first driver includes a first plurality of drive transistors that when activated drive an ultrasound transmitter output to a first voltage. The first bias network is coupled to the first plurality of drive transistors, and, at least in part, controls distribution, across the drive transistors, of voltage at the ultrasound transmitter output. Control inputs of the first driver are decoupled from the ultrasound transmitter output.

Claims

1. An ultrasound transmitter, comprising:

a first driver comprising a first plurality of drive transistors that when activated drive a ultrasound transmitter output to a first voltage;

a first bias network coupled to the first plurality of drive transistors, that, at least in part, controls distribution across the drive transistors of voltage at the ultrasound transmitter output;

wherein control inputs of the first driver are decoupled from the ultrasound transmitter output.

2. The ultrasound transmitter of claim 1, wherein a node of the first bias network is grounded.

3. The ultrasound transmitter of claim 1, wherein current flow through the first bias network is reduced when the first driver is disabled.

4. The ultrasound transmitter of claim 1, wherein the transmitter output voltage is not fed back into the first bias network.

5. The ultrasound transmitter of claim 1, wherein the first driver drives a positive voltage onto the transmitter output, and the first plurality of drive transistors comprises a P-type device coupled in series between the ultrasound transmitter output and an N-type device.

6. The ultrasound transmitter of claim 1, further comprising a buffer driver coupled between the bias network and a drive transistor of the first driver.

7. The ultrasound transmitter of claim 1, further comprising:

a second driver comprising a second plurality of drive transistors that when activated drive the ultrasound transmitter output to a second voltage;

a second bias network coupled to the second plurality of drive transistors, that, at least in part, controls distribution across the drive transistors of voltage at the ultrasound transmitter output;

wherein control inputs of the second driver are decoupled from the ultrasound transmitter output.

8. The ultrasound transmitter of claim 7, wherein the control inputs of the first driver are decoupled from the control inputs of the second driver.

9. The ultrasound transmitter of claim 7, wherein a node of the second bias network is grounded.

10. The ultrasound transmitter of claim 7, wherein the transmitter comprises no clamping circuit that brings the ultrasound transmitter output to ground when the first and second drivers are disabled.

11. The ultrasound transmitter of claim 7, wherein the second driver drives a negative voltage onto the ultrasound transmitter output, and the second plurality of drive transistors comprises an N-type device coupled in series between the ultrasound transmitter output and a P-type device.

12. An ultrasound imaging system, comprising:

a ultrasound receiver that receives detected ultrasonic signals;

an ultrasound transmitter that drives a transducer that converts electrical signals

into acoustic signals, the transmitter comprising;

a high-side driver that drives a transmitter output to a positive voltage;

a low-side driver that drives the transmitter output to a negative voltage; and

a bias network that substantially equalizes the voltage across drive transistors of each of the high-side driver and the low-side driver;

wherein a node of the bias network is connected to ground.

13. The ultrasound imaging system of claim 12, wherein disabling the high-side driver and the low-side driver reduces current flow in the bias network.

14. The ultrasound imaging system of claim 12, wherein the bias network is decoupled from the transmitter output.

15. The ultrasound imaging system of claim 12, wherein control of the high-side driver and the low-side driver is decoupled from the transmitter output.

16. The ultrasound imaging system of claim 12, wherein each of the first driver and the second driver comprises a pair of stacked complementary drive transistors.

17. The ultrasound imaging system of claim 12, wherein transmitter output current flows through an N-channel field effect transistor (“

FET”

) to a P-channel FET, and through the P-channel FET to the transmitter output.

18. The ultrasound imaging system of claim 12, wherein transmitter output current flows from the transmitter output through an N-channel FET to a P-channel FET.

19. An ultrasound transmitter, comprising:

a plurality of drive transistor that drive an ultrasound transmitter output; and

means for decoupling the control inputs of the plurality of drive transistors from the ultrasound transmitter output.

20. The ultrasound transmitter of claim 19, further comprising:

means for reducing current flow in a bias network that controls voltage drop across each drive transistor of the plurality of drive transistors when ultrasound transmitter output drive is disabled.