Circuit to Control the Effect of Dielectric Absorption in Dynamic Voltage Scaling Low Dropout Regulator
First Claim
1. A dielectric absorption current compensation circuit for generating a profile compensation current that is applied to an output of the low dropout voltage regulator and in parallel with a load capacitor to compensate for the dielectric absorption current comprising:
- a profile current generator that generates the profile compensation current and in communication with the output of the low dropout voltage regulator for transferring the profile compensation current to the load capacitor to compensate for the dielectric absorption current.
1 Assignment
0 Petitions
Accused Products
Abstract
A circuit and method provides compensation for disturbance of an output voltage caused by dielectric absorption of a load capacitor of a low dropout voltage regulator after a modification of the output voltage level of the low dropout voltage regulator. A dielectric absorption current compensation circuit generates a profile current that is applied to an output of the low dropout voltage regulator and in parallel with the load capacitor to compensate for the dielectric absorption current. The dielectric absorption current compensation circuit has a programmable profile current generator that generates the profile current. A switchable current mirror transfers a mirror profile compensation current to the load capacitor to compensate for the dielectric absorption current. In some embodiments, the profile current is a continuous profile dielectric absorption compensation current and in other embodiments, the profile current is a digital profile dielectric absorption compensation current.
14 Citations
26 Claims
-
1. A dielectric absorption current compensation circuit for generating a profile compensation current that is applied to an output of the low dropout voltage regulator and in parallel with a load capacitor to compensate for the dielectric absorption current comprising:
a profile current generator that generates the profile compensation current and in communication with the output of the low dropout voltage regulator for transferring the profile compensation current to the load capacitor to compensate for the dielectric absorption current. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
11. A low dropout voltage regulator comprises:
a dielectric absorption current compensation circuit for generating a profile compensation current that is applied to an output of the low dropout voltage regulator and in parallel with a load capacitor to compensate for the dielectric absorption current comprising; a profile current generator that generates the profile compensation current and in communication with the output of the low dropout voltage regulator for transferring the profile compensation current to the load capacitor to compensate for the dielectric absorption current. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
21. A method for compensating for the dielectric absorption current from the recharging of the output load capacitor of a low dropout voltage regulator comprising the steps of:
-
requesting the low voltage regulator to decrease its output voltage; enabling an internal load current source to decrease the output voltage of the low dropout voltage regulator by adjusting the charge of the output load capacitor; ramping down an output voltage level of the low dropout voltage regulator until it brought to a lower voltage level; disabling the internal load voltage source is disabled; applying a profile compensation current after the low dropout voltage regulator is disabled to counteract the dielectric absorption current of the recharging output load capacitor to prevent the low dropout voltage regulator from becoming unregulated. - View Dependent Claims (22, 23)
-
-
24. An apparatus for compensating for the dielectric absorption current from the recharging of the output load capacitor of a low dropout voltage regulator comprising:
-
means for requesting the low voltage regulator to decrease its output voltage; means for enabling an internal load current source to decrease the output voltage of the low dropout voltage regulator by adjusting the charge of the output load capacitor; means for ramping down an output voltage level of the low dropout voltage regulator until it brought to a to a lower voltage level; means for disabling the internal load voltage source is disabled; and means for applying a profile compensation current after the low dropout voltage regulator is disabled to counteract the dielectric absorption current of the recharging output load capacitor to prevent the low dropout voltage regulator from becoming unregulated. - View Dependent Claims (25, 26)
-
Specification