Apparatus for high voltage tolerant driver

Patent metadata

Field	Value
Publication number	US-9813064-B2
Application number	US-201314109484-A
Country	US
Kind code	B2
Filing date	Dec 17, 2013
Priority date	Dec 17, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

Described is an apparatus which comprises: a first power supply; a second power supply lower than the first power supply; first and second transistors coupled in series and to be biased, the first and second transistors coupled to a pad; a first pull-up transistor coupled to the first power supply and to one of the first or second transistors; a pull-down transistor coupled to one of the first or second transistors; and a second pull-up transistor coupled to the second power supply, the pull-down transistor, and to one of the first or second transistors.

First claim

We claim:

1. An apparatus comprising:
a first power supply;
a second power supply lower than the first power supply;
first and second transistors coupled in series and coupled to a bias signal and a pad;
a first pull-up transistor coupled to the first power supply and to the first transistor;
a pull-down transistor coupled to the second transistor; and
a second pull-up transistor coupled to the second power supply, the pull-down transistor, and to the second transistor, wherein the first pull-up transistor, the first and second transistors and the pull-down transistor form a first driver to operate in a first mode of operation, and the second pull-up transistor, the pull-down transistor and the second transistor form a second driver to operate in a second mode of operation.

2. The apparatus of claim 1 , wherein the second pull-up transistor is operable to be turned off in the first mode of operation in which the first pull-up transistor is turned on.

3. The apparatus of claim 1 , wherein the second pull-up transistor is operable to be turned on in the second mode of operation in which the first pull-up transistor is turned off.

4. The apparatus of claim 1 , wherein the first transistor and the first pull-up transistor are p-type devices.

5. The apparatus of claim 1 , wherein the second transistor and the pull-down transistor are n-type devices.

6. The apparatus of claim 1 , wherein the first power supply is substantially 3.3V and the second power supply is in the range of 0.5V to 1.2V.

7. The apparatus of claim 1 , wherein the second pull-up transistor is a p-type device.

8. The apparatus of claim 1 , wherein the first driver is a USB compliant high speed (HS) driver for lower power operation, the second driver is a USB compliant classic (CL) driver for higher power operation.

9. A driver comprising:
a first pull-up transistor coupled to a first power supply, the first pull-up transistor controllable by a first pre-driver;
a second pull-up transistor coupled to a second power supply, the second pull-up transistor controllable by a second pre-driver;
first and second transistors coupled in series and coupled to a first bias signal and a first pad, the first and second transistors separating the first pull-up transistor from the second pull-up transistor, the first transistor coupled to the first pull-up transistor and the second transistor coupled to the second pull-up transistor; and
a first pull-down transistor coupled to the second pull-up transistor,
wherein the first pull-up transistor, the first and second transistors and the pull-down transistor form a first driver to operate in a first mode of operation, and the second pull-up transistor, the pull-down transistor and the second transistor form a second driver to operate in a second mode of operation.

10. The driver of claim 9 , wherein the second pull-up transistor is operable to be turned off in the first mode of operation in which the first pull-up transistor is turned on.

11. The driver of claim 9 , wherein the second pull-up transistor is operable to be turned on in the second mode of operation in which the first pull-up transistor is turned off.

12. The driver of claim 9 , wherein the first power supply is greater than the second power supply.

13. The driver of claim 9 , wherein the first pull-up transistor, second pull-up transistor, first and second transistors, and first pull-down transistor are part of a USB transmitter.

14. The driver of claim 8 further comprises:
a third pull-up transistor coupled to the first power supply, the third pull-up transistor controllable by a third pre-driver;
a fourth pull-up transistor coupled to the second power supply, the fourth pull-up transistor controllable by a fourth pre-driver;
third and fourth transistors coupled in series and coupled to a second bias signal and a second pad, the third and fourth transistors separating the third pull-up transistor from the fourth pull-up transistor; and
a second pull-down transistor coupled to the second pull-up transistor.

15. The driver of claim 14 , wherein the first and third pull-up transistors, second and fourth pull-up transistors, first, second, third, and fourth transistors, and first and second pull-down transistors are part of a differential USB transmitter.

16. The driver of claim 14 , wherein the first and second pads output differential output signals.

17. The driver of claim 9 , wherein the first power supply is substantially 3.3V and the second power supply is in the range of 0.5V to 1.2V.

18. The driver of claim 9 , wherein the first driver is a USB compliant high speed (HS) driver for lower power operation, and the second driver is a USB compliant classic (CL) driver for higher power operation.

19. A driver comprising:
a first pull-up transistor coupled to a first power supply, the first pull-up transistor controllable by a first pre-driver;
a second pull-up transistor coupled to a second power supply, the second pull-up transistor controllable by a second pre-driver;
first and second transistors coupled in series between the first pull-up transistor and the second pull-up transistor and coupled to a first bias signal and a first pad;
a first pull-down transistor coupled to the second pull-up transistor;
a third pull-up transistor coupled to the first power supply, the third pull-up transistor controllable by a third pre-driver;
a fourth pull-up transistor coupled to the second power supply, the fourth pull-up transistor controllable by a fourth pre-driver;
third and fourth transistors coupled in series between the third pull-up transistor and the fourth pull-up transistor and coupled to a second bias signal and a second pad; and
a second pull-down transistor coupled to the second pull-up transistor.

20. The driver of claim 19 , wherein the first and third pull-up transistors, second and fourth pull-up transistors, first, second, third, and fourth transistors, and first and second pull-down transistors are part of a differential USB transmitter.

Assignees

• Low Chia How
• Leong Chee Seng
• Ho Yick Yaw
• Intel Corp

Inventors

• Low Chia How
• Leong Chee Seng
• Ho Yick Yaw

Classifications

• H03K3/011

  Modifications of generator to compensate for variations in physical values, e.g. voltage, temperature {(to maintain energy constant H03K3/015)} · CPC title

• Y10T307/305

  Cross-Sectional Technologies · mapped topic

• H03K19/017581 Primary

  programmable · CPC title