Compensating a two stage amplifier
View Patent ↗Systems and techniques are disclosed for configuring a circuit containing a two-stage amplifier including a first stage containing at least a differential amplifier, a second stage containing at least a transistor, and a sensing circuit configured to provide a gate voltage to a compensation component. The compensation component may be configured to connect the first stage and the second stage and to generate a lead-lag compensation. The compensation component may contain a compensation capacitor and a variable compensation resistive component in series connection with the compensation capacitor.
1. A circuit comprising:
a two-stage amplifier comprising:
a first stage comprising a differential amplifier; and
a second stage comprising a transistor;
a sensing circuit, to detect a first voltage and a second voltage, where the second voltage is detected based on the first voltage;
a compensator in signal communication with the first stage and with the second stage, the compensator comprising:
a compensation capacitor; and
a variable compensation resistive component, the value of which is determined based on the detected second voltage, in series with the compensation capacitor,
wherein the compensator generates a lead-lag compensation.
2. The circuit of claim 1 , configured to output a reference voltage, wherein the reference voltage is substantially fixed for a range of load currents.
3. The circuit of claim 2 , wherein the resistance value of the variable compensation resistive component is determined based on the output voltage.
4. The circuit of claim 2 , wherein the resistance value of the variable compensation resistive component is determined based on the load current.
5. The circuit of claim 3 , further configured to:
detect the first voltage based on at least one selected from the group consisting of: the output voltage and the load current.
6. The circuit of claim 5 , wherein the variable compensation resistive component comprises a first transistor in parallel with a resistor, the first transistor configured to have a gate voltage proportional to the second voltage.
7. The circuit of claim 1 , wherein the resistive value for the variable compensation resistive component is configured to maintain a stable output voltage.
8. The circuit of claim 1 , wherein variable compensation resistive component comprises:
a resistor; and
a first transistor in parallel with the resistor.
9. The circuit of claim 8 , wherein the first transistor is biased in the triode region.
10. The circuit of claim 1 , wherein the transistor comprises a bi-polar junction transistor.
11. The circuit of claim 1 , wherein the transistor comprises a field-effect transistor is at least one selected from the group consisting of: a metal-oxide semiconductor field-effect transistor and a junction gate field-effect transistor.
12. A system comprising:
a two-stage amplifier comprising:
a first stage comprising at least a differential amplifier; and
a second stage comprising a transistor;
a sensing circuit, to detect a first voltage and a second voltage, where the second voltage is detected based on the first voltage;
a compensator in signal communication with the first stage and with the second stage, the compensator comprising:
a compensation capacitor; and
a variable compensation resistive component, the value of which is determined based on the detected second voltage, in series with the compensation capacitor;
wherein the compensator generates a lead-lag compensation.
13. The system of claim 12 , configured to output a reference voltage, wherein the reference voltage is substantially fixed for a range of load currents.
14. The system of claim 13 , wherein the resistance value of the variable compensation resistive component is determined based on the output voltage.
15. The system of claim 13 , wherein the resistance value of the variable compensation resistive component is determined based on the load current.
16. The system of claim 14 , further configured to:
detect the first voltage based on at least one selected from the group consisting of: the output voltage and the load current.
17. The system of claim 16 , wherein the variable compensation resistive component comprises a first transistor in parallel with a resistor, the first transistor configured to have a gate voltage proportional to the second voltage.
18. The system of claim 12 , wherein the resistive value for the variable compensation resistive component is configured to maintain a stable output voltage.
19. The system of claim 12 , wherein variable compensation resistive component comprises:
a resistor; and
a first transistor in parallel with the resistor.
20. The system of claim 19 , wherein the first transistor is biased in the triode region.
21. The system of claim 12 , wherein the transistor comprises a bi-polar junction transistor.
22. The system of claim 12 , wherein the transistor comprises a field-effect transistor is at least one selected from the group consisting of: a metal-oxide semiconductor field-effect transistor and a junction gate field-effect transistor.