USB integrated bidirectional digital isolator

• US 20090031056A1
• Filed: 07/26/2007
• Published: 01/29/2009
• Est. Priority Date: 07/26/2007
• Status: Active Grant

• Current Assignee: Kinetic Technologies International Holdings LP
• Original Assignee: Akros Silicon, Inc. (Kinetic Technologies Incorporated)
• Inventors: Bliss, Davis, Ghoshal, Sajol
• Granted Patent: US 7,899,968 B2
• Time in Patent Office: Days
• US Class Current: 710/31
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence

Abstract

An interface between USB devices employs isolation techniques to provide electrical isolation of a USB signal for transmission of the USB signal between the devices. Unidirectional isolator channels are utilized to transmit the USB signals, and a selection of an isolator channel operating in an intended direction is performed by either direction control logic or a USB hub function. Logic may be employed to detect a device attempting to initiate a USB signal. The logic operates to enable a transmitter on a receiving side and isolate the USB signal through an isolator channel operating in a transmission direction.

Claims

1. A method of communicating and isolating a digital signal across an interface between two devices, the method comprising:

detecting an initiation for a transmission of the digital signal from a transmitting device to a receiving device;

transmitting the digital signal through an isolator channel in a direction of the transmission of the digital signal;

enabling a receiving device transceiver for receiving the digital signal; and

transmitting the isolated digital signal to the receiving device.

2. The method of claim 1, wherein detecting an initiation for a transmission of the digital signal comprises monitoring the digital signal for a transition from an idle state to a non-idle state.

3. The method of claim 1, further comprising:

detecting a completion of the transmission of the digital signal; and

disabling the receiving device transceiver

4. The method of claim 3, wherein detecting a completion of the transmission of the digital signal comprises monitoring the digital signal for a transition from a non-idle state to an idle state.

5. The method of claim 3, wherein disabling the receiving device transceiver comprises disabling the receiving device transceiver after a predetermined number of cycles elapse after the detection of the completion of the transmission of the digital signal.

6. The method of claim 1, wherein one of the two devices is a USB host, and wherein the second of the two devices is a USB device.

7. A USB isolator component for providing electrical isolation between a USB host and a USB device, wherein a USB signal is communicated between the USB host and the USB device, the USB isolator component comprising:

bidirectional communication ports for transmitting and receiving the USB signal between the two devices;

USB physical layer components connected to the bidirectional communication ports for receiving and transmitting the USB signal;

a USB hub controller connected to the USB physical layer components for determining a direction of transmission of the USB signal; and

isolator channels for isolating and transmitting the USB signal in the determined transmission direction.

8. The USB isolator component of claim 7, wherein a USB physical layer component is divided into a clock data recovery component and a transceiver component.

9. The USB isolator component of claim 8, wherein the isolator channels are connected between the clock data recovery component and the transceiver component of the divided USB physical layer component.

10. The USB isolator component of claim 7, wherein the isolator channels are connected between the USB hub controller and one USB physical layer component.

11. One or more integrated circuit device having a process embodied in said integrated circuit device, said process performing a method of isolating a digital signal across a USB interface between two USB devices, the method comprising:

detecting an initiation for a transmission of the digital signal;

determining a transmission direction of the digital signal;

transmitting the digital signal through an isolator channel in the determined transmission direction; and

transmitting the isolated digital signal to the receiving device.

12. The one or more integrated circuit device of claim 11, wherein detecting an initiation for a transmission of the digital signal comprises monitoring the digital signal for a transition from an idle state to a non-idle state.

13. The one or more integrated circuit device of claim 11, wherein said process performs the further method of:

enabling a receiving device transceiver for transmitting the digital signal to the receiving device.

14. The one or more integrated circuit device of claim 12, wherein said process performs the further method of:

disabling the receiving device transceiver upon completion of the transmission of the digital signal.

15. The one or more integrated circuit device of claim 14, wherein said process performs the further method of:

detecting completion of the transmission of the digital signal by monitoring the digital signal for a transition from a non-idle state to an idle state.