Granted Patent B2

US 9,442,501 · App. 14/287,395 · Granted Sep 13, 2016

Abstract

Claims (40)

1. A voltage regulator comprising:

a single substrate including circuitry to implement:

a first amplifier stage operable to provide a first gain level at a first bandwidth;

a second amplifier stage coupled to the first amplifier stage, the second amplifier stage operable to provide a second gain level at a second bandwidth, wherein the first gain level is higher than the second gain level, and the second bandwidth is higher than the first bandwidth;

a dynamic compensation circuit coupled to an output of the second amplifier stage, the dynamic compensation circuit operable to provide a varying level of compensation to the second amplifier stage, the varying level of compensation proportional to a current level associated with a load; and

a current compensation circuit coupled to an output of a third amplifier stage, the current compensation circuit operable to allow a minimum current level at the third amplifier stage, the third amplifier stage coupled to the first and second amplifier stages.

2. The voltage regulator of claim 1 , wherein the minimum current level is constant.

3. The voltage regulator of claim 1 , wherein the minimum current level is a function of the load.

4. The voltage regulator of claim 1 , wherein the dynamic compensation circuit comprises a transistor having a gate voltage modulated by a current level associated with the third amplifier stage.

5. The voltage regulator of claim 1 , wherein the output of the third amplifier stage is coupled directly to an output pin of the single substrate.

6. The voltage regulator of claim 1 , wherein the load is formed on the single substrate.

7. The voltage regulator of claim 1 , wherein the direct voltage gain of the voltage regulator is greater than forty decibels.

8. The voltage regulator of claim 1 , wherein the voltage regulator is responsive to a direct current equivalent load within the range of two to five hundred milliamps (2-500 mA).

9. The voltage regulator of claim 1 , wherein an equivalent capacitance coupled to an output of the voltage regulator is within the range of five to one hundred nanofarads (5-100 nF).

10. The voltage regulator of claim 1 , wherein the voltage regulator is operable to provide a phase margin greater than thirty degrees.

11. The voltage regulator of claim 1 , wherein the current compensation circuit comprises:

a first transistor of the first type having a first current electrode coupled to a first electrode of a resistor, a control electrode coupled to a bias voltage, and a second current electrode coupled to a first supply voltage;

a capacitor coupled in parallel between a second electrode of the resistor and a second supply voltage; and

a first transistor of a second type having a first current electrode coupled to an input voltage, a control electrode coupled to the second electrode of the resistor, and a second current electrode coupled to the second supply voltage.

12. The voltage regulator of claim 1 , wherein the dynamic compensation circuit comprises:

a first transistor of a first type having a first current electrode coupled to an output of the second amplifier stage, a second current electrode coupled to a source voltage; and

a second transistor of the first type having a first current electrode coupled to the source voltage, and a second current electrode and a control electrode coupled to: one another, and a control electrode of the first transistor of the first type.

13. A semiconductor device comprising:

a load;

a voltage regulator coupled to the load, the voltage regulator comprising:

a multipath amplifier stage;

a driver stage coupled to the multipath amplifier stage;

a dynamic compensation circuit coupled to the multipath amplifier stage, the dynamic compensation circuit operable to provide a varying level of compensation to the multipath amplifier stage, the varying level of compensation proportional to a current level associated with the load; and

a current compensation circuit coupled between the load and the input to the multipath amplifier stage, the current compensation circuit operable to provide a minimum current level at the driver stage and includes:

a first transistor of the first type having a first current electrode coupled to an input signal and a first electrode of a resistor, a control electrode coupled to a bias voltage, and a second current electrode coupled to a first supply voltage;

a capacitor coupled in parallel between a second electrode of the resistor and the first supply voltage; and

a first transistor of a second type having a first current electrode coupled to an input voltage, a control electrode coupled to the second electrode of the resistor, and a second current electrode coupled to a second supply voltage.

14. The semiconductor device of claim 13 , wherein the load and the voltage regulator are formed on the same substrate.

15. The semiconductor device of claim 13 , wherein an output of the driver stage is an output of the semiconductor device.

16. The semiconductor device of claim 13 , wherein the minimum current level is constant.

17. The semiconductor device of claim 13 , wherein the minimum current level is a function of the load.

18. The semiconductor device of claim 13 , wherein the dynamic compensation circuit comprises a transistor coupled to a compensation resistor, the transistor having a gate voltage modulated by a current level associated with a third amplifier stage.

19. The semiconductor of claim 13 , wherein the dynamic compensation circuit comprises:

a first transistor of a first type having a first current electrode coupled to an output of the multipath amplifier stage, a second current electrode coupled to a source voltage; and

a second transistor of the first type having a first current electrode coupled to the source voltage, and a second current electrode and a control electrode coupled to: one another, a control electrode of the first transistor of the first type, and an input signal.

Assignments (16)