Signal conditioner

Abstract

A signal conditioner can include a state machine configured to detect a predetermined protocol level mode of a data signal on a bi-directional serial bus. The signal conditioner can also include a re-driver configured to inject current into at least one of a rising edge and a falling edge of the data signal on the bi-directional serial bus in response to the detection of the predetermined protocol level mode.

What is claimed is: 
     
         1 . A signal conditioner comprising:
 a state machine configured to detect a predetermined protocol level mode of a data signal on a bi-directional serial bus; and   a re-driver configured to inject current into at least one of a rising edge and a falling edge of the data signal on the bi-directional serial bus in response to the detection of the predetermined protocol level mode.   
     
     
         2 . The signal conditioner of  claim 1 , wherein the bi-directional serial bus is a universal serial bus (USB). 
     
     
         3 . The signal conditioner of  claim 2 , wherein the predetermined protocol level mode is the High-Speed USB protocol. 
     
     
         4 . The signal conditioner of  claim 3 , wherein the data signal is provided on the D+ and D− lines of the USB. 
     
     
         5 . The signal conditioner of  claim 1 , wherein the state machine is configured to disable the re-driver in response to detecting a protocol level mode other than the predetermined protocol level mode. 
     
     
         6 . The signal conditioner of  claim 1 , wherein the re-driver further comprises:
 a rising edge detector configured to detect a rising edge of the data signal that has a rise time greater than a predetermined maximum rise time; and   a falling edge detector configured to detect a falling edge of the data signal that has a fall time greater than a predetermined maximum fall time.   
     
     
         7 . The signal conditioner of  claim 6 , wherein the re-driver further comprises:
 a positive current booster configured to inject a positive current in to the data signal in response to an given activation signal provided from the rising edge detector; and   a negative current booster configured to inject a negative current in to the data signal in response to another activation signal provided from the falling edge detector.   
     
     
         8 . The signal conditioner of  claim 7 ,
 wherein the positive current booster is further configured to not provide the given activation signal to the positive current booster in response to determining that the rising edge of the data signal has a rise time less than the predetermined maximum rise time; and   wherein the negative current booster is further configured to not provide the another activation signal to the negative current booster in response to determining that the falling edge of the data signal has a fall time less than the predetermined maximum fall time.   
     
     
         9 . The signal conditioner of  claim 6 , wherein the positive current booster comprises an independent current source with a programmable current range of about 2 milliamperes (mA) to about 6 mA. 
     
     
         10 . The signal conditioner of  claim 1 , wherein the state machine is further configured to detect the predetermined protocol level mode based on waveform properties of the data signal. 
     
     
         11 . The signal conditioner of  claim 1 , wherein the state machine and the re-driver are implemented on separate integrated circuit (IC) chips. 
     
     
         12 . An integrated circuit (IC) chip comprising the signal conditioner of  claim 1 . 
     
     
         13 . A system comprising:
 a given universal serial bus (USB) device that communicates with another USB device via a USB channel; and   a signal conditioner comprising:
 a state machine configured to detect a predetermined protocol level mode of a data signal propagated on the USB channel; and 
 a re-driver configured to inject current into at least one of a rising edge and a falling edge of the data signal on the USB channel in response to the detection of the predetermined protocol level mode. 
   
     
     
         14 . The system of  claim 13 , wherein the predetermined protocol level mode is the High-Speed USB protocol. 
     
     
         15 . The system of  claim 14 , wherein the state machine is configured to disable the re-driver in response to detecting a protocol level mode other than the High-Speed USB protocol. 
     
     
         16 . The system of  claim 13 , wherein the signal conditioner is implemented in an integrated circuit (IC) chip located within a USB port of the given USB device. 
     
     
         17 . The system of  claim 13 , wherein the state machine is further configured to detect the predetermined protocol level mode based on waveform properties of the data signal. 
     
     
         18 . A method comprising:
 detecting, at a state machine, a predetermined protocol level mode of a data signal propagated across a universal serial bus (USB);   injecting, by a re-driver, a positive current into the data signal in response to detecting a rising edge of the data signal that has a rise time greater than a predetermined maximum rise time; and   injecting, by the re-driver, a negative current into the data signal in response to detecting a falling edge of the data signal that has a fall time greater than a predetermined maximum fall time.   
     
     
         19 . The method of  claim 18 , further comprising preventing, by the state machine, the injecting of the positive current and the negative current in response to detecting a protocol level mode other than the predetermined protocol level mode on the USB. 
     
     
         20 . The method of  claim 19 , wherein the predetermined protocol level mode is the High-Speed USB protocol.