Xdsl multistandard driver circuit

Abstract

An electric circuit for amplifying an xDSL signal comprises an operational amplifier and a signal monitoring circuit. The operational amplifier is configured to amplify the xDSL signal, is powered by a variable voltage supply and has a gain which is adjustable by an operating mode control signal. The signal monitoring circuit is activated by the operating mode control signal and is configured, when activated by the operating mode control signal, to generate a control signal to adjust the voltage of the variable voltage supply in order to adjust the maximal signal swing of the output signal of said operational amplifier. The control signal is generated by comparing the amplitude of the xDSL signal applied to the electric circuit with an amplitude threshold value.

1 . An multistandard driver circuit for amplifying a signal applied to an input of the multistandard driver circuit, the multistandard driver circuit configured to be adjusted to different settings of different standards and comprising:
 an operational amplifier configured to amplify the signal applied to the multistandard driver circuit;   a voltage supply to power the operational amplifier; and   a signal monitoring circuit configured to adjust the voltage of the voltage supply in order to adjust a signal swing of an output signal of the operational amplifier, the signal monitoring circuit to adjust the voltage of the voltage supply by comparing an amplitude of the signal to an amplitude threshold value.   
     
     
         2 . The xDSL multistandard driver circuit of  claim 1 , wherein a signal gain for amplifying the signal is adjusted on the basis of an operating mode of an operating mode control signal, the operating mode control signal to active the signal monitoring circuit. 
     
     
         3 . A method for adapting an amplifier to a signal comprising:
 providing the amplifier with a supply voltage;   applying a signal associated with one of a first or second mode to the amplifier;   selecting a feedback resistance corresponding to the mode associated with the signal;   measuring the signal if the signal is associated with the second mode;   adjusting the supply voltage when a measured amplitude of the signal exceeds a threshold value.   
     
     
         4 . A multimode driver comprising:
 an amplifier configured to amplify an input signal;   a mode selector to control at least one operational parameter of the amplifier;   a signal monitor, responsive to the mode selector, to selectively measure the input signal and vary a supply voltage to the amplifier in response thereto.   
     
     
         5 . The multimode driver of  claim 4 , wherein the voltage of the supply voltage is adjusted in order to adjust a signal swing of an output signal of the amplifier. 
     
     
         6 . The multimode driver of  claim 4 , wherein the at least one operational parameter of the amplifier is varied if an amplitude of the input signal exceeds an amplitude threshold value. 
     
     
         7 . The multimode driver of  claim 4 , wherein the at least one operational parameter is at least a feedback resistance. 
     
     
         8 . The multimode driver of  claim 4 , wherein the supply voltage is directly related to an amplitude of the input signal. 
     
     
         9 . The multimode driver of  claim 4 , wherein the mode selector is to select a first mode in accordance with a first feedback resistance and a second mode in accordance with a second feedback resistance. 
     
     
         10 . The multimode driver of  claim 9 , wherein the supply voltage of the first mode is ±6V. 
     
     
         11 . The multimode driver of  claim 9 , wherein the supply voltage of the second mode is varied between a low supply voltage of ±6V and a high supply voltage of ±12V. 
     
     
         12 . The multimode driver of  claim 9 , wherein the signal monitor is inactive in the first mode. 
     
     
         13 . The multimode driver of  claim 9 , wherein the signal monitor varies the supply voltage to the amplifier in the second mode. 
     
     
         14 . The multimode driver of  claim 4 , wherein the multimode driver is a multimode xDSL driver. 
     
     
         15 . A multistandard driver to amplify a signal, the multistandard driver configured to be adjusted to different settings of different standards according to an operating mode control signal and comprising:
 an amplifier configured to amplify the signal;   a signal monitor activated by the operating mode control signal, the signal monitor configured to influence a voltage provided to the amplifier in accordance with a comparison of an amplitude of the signal to an amplitude threshold value.   
     
     
         16 . The multistandard driver of  claim 15 , wherein the voltage provided to the amplifier is to adjust a signal swing of an output signal of the amplifier. 
     
     
         17 . The multistandard driver of  claim 15 , further comprising at least one impedance and a selector, the selector configured couple the at least one impedance between an output and an input of the amplifier to adjust a gain of the amplifier. 
     
     
         18 . The multistandard driver of  claim 15 , wherein the multistandard driver is a xDSL multistandard driver. 
     
     
         19 . The multistandard driver of  claim 15 , wherein the signal monitor is deactivatable by the operating mode control signal. 
     
     
         20 . The multistandard driver of  claim 17 , wherein the selector is controlled by the operating mode control signal.