Compensation device for feedback loops, and corresponding integrated circuit

• US 9,479,180 B2
• Filed: 07/10/2015
• Issued: 10/25/2016
• Est. Priority Date: 07/18/2014
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Bellitra, Matteo, Botti, Edoardo
• Primary Examiner(s): Hernandez, William
• Application Number:
  US14/796,396
• Publication Number:
  US 20160020755A1
• Time in Patent Office: 473 Days
• Field of Search: 327/306, 327/331, 327/332, 327/362, 327/363, 327/538, 327/540, 327/541, 327/543, 327/590
• US Class Current: 1/1
• CPC Class Codes: G05F 1/613 using semiconductor devices in parallel with the load as final control devices G05F1/461 takes precedence
• CPC Class Codes: H03K 19/00315 in field-effect transistor circuits
• CPC Class Codes: H03K 5/003 Changing the DC level reinsertion of dc component of a television signal H04N5/16
• CPC Class Codes: H03L 5/00 Automatic control of voltage, current, or power

Abstract

An electronic device includes an output terminal, an output transistor having a control terminal and a conduction terminal coupled to the output terminal, and a resistor-capacitor (RC) compensation network configured to act on the control terminal of the output transistor. In addition, the electronic device includes a transconductance amplifier configured to drive the output terminal through the control terminal of the output transistor, and a Miller effect stage coupled to the RC compensation network and having an input port coupled to the transconductance amplifier and an output port coupled to the control terminal of the output transistor.

Claims

1. An electronic device comprising:

an output terminal;

an output transistor having a control terminal and a conduction terminal coupled to the output terminal;

a resistor-capacitor (RC) compensation network configured to act on the control terminal of the output transistor;

a transconductance amplifier configured to drive the output terminal through the control terminal of the output transistor; and

a Miller effect stage coupled to the RC compensation network in a current flow path between the output terminal and a reference voltage, and having an input port coupled to the transconductance amplifier and an output port coupled to the control terminal of the output transistor.

2. The electronic device of claim 1, wherein the Miller effect stage comprises a first pair of transistors and a second pair of transistors coupled together.

3. The electronic device of claim 2, wherein the first and second pair of transistors each includes respective first and second transistors cascaded in the current flow path between the output terminal and the reference voltage.

4. The electronic device of claim 2, wherein the first transistors of the first and second pairs of transistors have respective control terminals configured to be driven by the transconductance amplifier.

5. The electronic device of claim 2, wherein the capacitor of the RC compensation network is between respective control terminals of the second transistors in the first and second pairs of transistors;

and

the control terminal of the output transistor is configured to be driven via a point of a current flow path through the second pair of transistors and between the transistors of the second pair of transistors.

6. The electronic device of claim 2, further comprising:

a first resistor in the current flow path between the output terminal and the reference voltage passing through the first pair of transistors; and

a second resistor in the current flow path between the output terminal and the reference voltage passing through the second pair of transistors.

7. The electronic device of claim 5, wherein the current flow path between the output terminal and the reference voltage passing through the first pair of transistors and the current flow path between the output terminal and the reference voltage passing through the second pair of transistors have a common section, and a common resistor is in the common section.

8. The electronic device of claim 3, further comprising a current generator to counter turning-off of the first transistors that are driven by the transconductance amplifier.

9. The electronic device of claim 3, wherein the RC compensation network comprises a low-pass RC network.

10. The electronic device of claim 9, wherein the low-pass RC network is between the control terminals of the second transistors of the first and second pairs of transistors.

11. The electronic device of claim 2, wherein the first pair of transistors and the second pair of transistors include transistors of opposite polarities.

12. The electronic device of claim 2, wherein the output transistor, the first and second pairs of transistors are field effect transistors having a gate acting as the control terminal and having a current flow path between source and drain.

13. The electronic device of claim 1, further comprising a semiconductor substrate;

and wherein the output transistor, transconductance amplifier, and Miller effect stage are on the semiconductor substrate.

14. An electronic device comprising:

an output terminal;

an output transistor having a control terminal and a conduction terminal coupled to the output terminal;

a resistor-capacitor (RC) compensation network;

a transconductance amplifier coupled to the control terminal of the output transistor; and

a Miller effect stage coupled to the RC compensation network in a current flow path between the output terminal and a reference voltage, and having an input port coupled to the transconductance amplifier and an output port coupled to the control terminal of the output transistor.

15. The electronic device of claim 14, wherein the Miller effect stage comprises a first pair of transistors and a second pair of transistors coupled thereto.

16. The electronic device of claim 15, wherein the first and second pair of transistors each includes respective first and second transistors cascaded in the current flow path between the output terminal and the reference voltage.

17. A method of providing compensation with a device comprising an output terminal, an output transistor having a control terminal and a conduction terminal coupled to the output terminal, a resistor-capacitor (RC) compensation network, a transconductance amplifier coupled to the control terminal of the output transistor, and a Miller effect stage coupled to the RC compensation network in a current flow path between the output terminal and a reference voltage, and having an input port coupled to the transconductance amplifier and an output port coupled to the control terminal of the output transistor, the method comprising:

driving the output terminal through the control terminal of the output transistor via the transconductance amplifier; and

acting on the control terminal of the output transistor via the RC compensation network.

18. The method of claim 17, wherein the Miller effect stage comprises a first pair of transistors and a second pair of transistors coupled thereto.

19. The method of claim 18, wherein the first and second pair of transistors each includes respective first and second transistors cascaded in the current flow path between the output terminal and the reference voltage.