Transient power control

Abstract

Automatic transient control circuitry may be used to alleviate issues relating to large changes in power demands by a load in an integrated circuit. The transient control circuitry may inject current to or retract current from a load, for example charging or discharging a bypass capacitor associated with the load, when circuitry of the load is commanded to an operational state from a standby state or vice-versa, respectively.

1 .- 24 . (canceled) 
     
     
         25 . Circuitry useful in controlling transients in a power distribution system, comprising:
 a DC-DC switching converter coupled to a node for applying voltage to a power domain load; and   a first plurality of paths between a power source and the node, each of the first plurality of paths including at least one transistor for selectively coupling the path between the power source and the node, based on an enable signal and an output of a comparator comparing an indication of voltage at the node and at least one reference voltage.   
     
     
         26 .- 29 . (canceled) 
     
     
         30 . The circuitry of  claim 25 , wherein a magnitude of current supplied by a particular current path of the first plurality of paths is based on a magnitude of the output of the comparator. 
     
     
         31 .- 32 . (canceled) 
     
     
         33 . The circuitry of  claim 25 , further comprising an isolation switch coupled between the DC-DC switching converter and the node. 
     
     
         34 .- 36 . (canceled) 
     
     
         37 . The circuitry of  claim 25 , further comprising a second plurality of paths between the node and a lower power source, each of the second plurality of paths having a switch for selectively coupling the path between the node and the lower power source. 
     
     
         38 .- 40 . (canceled) 
     
     
         41 . The circuitry of  claim 25 , wherein the comparator is an analog comparator, the analog comparator the providing a difference signal indicative of a difference between the indication of voltage at the node and the reference voltage. 
     
     
         42 . The circuitry of  claim 41 , wherein the comparator comprises a differential amplifier. 
     
     
         43 . The circuitry of  claim 41 , further comprising a sample and hold circuit, the sample and hold circuit coupled to the comparator so as to receive the difference signal and the enable signal, an output of the sample and hold circuit coupled to the at least one transistor. 
     
     
         44 . The circuitry of  claim 41 , wherein the difference signal operates the at least one transistor in a linear range of the at least one transistor. 
     
     
         45 . The circuitry of  claim 25 , wherein the reference voltage is different for each of the first plurality of paths.