Synchronous switching regulator circuit

• US 10,270,348 B2
• Filed: 10/12/2017
• Issued: 04/23/2019
• Est. Priority Date: 02/23/2017
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Inventors: Cha, Choong Yul, Li, Dandan, Chien, Hung-Ming, Bu, Long, Au, Stephen C.
• Primary Examiner(s): Zhang, Jue
• Assistant Examiner(s): Jackson, Lakaisha
• Application Number:
  US15/782,753
• Publication Number:
  US 20180241312A1
• Time in Patent Office: 558 Days
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 3/137 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H03L 7/06 using a reference signal applied to a frequency- or phase-locked loop
• CPC Class Codes: H03L 7/08 Details of the phase-locked loop
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence

Abstract

A synchronous switching regulator circuit for supply regulation of a switching circuit includes a pass transistor to couple the switching circuit to a supply voltage. The synchronous switching regulator circuit further includes a switch that is operable to synchronously turn off a flow of a supply current through the pass transistor. The switching circuit can be controlled by a switching signal, and the switch can operate in synchronization with the switching circuit.

Claims

1. A synchronous switching regulator circuit, the circuit comprising:

a pass transistor configured to couple a switching circuit to a supply voltage; and

a switch operable to synchronously turn off a flow of a supply current through the pass transistor,

wherein;

the switching circuit is configured to be controlled by a switching signal, and

the switch is configured to be controlled by the switching signal to operate in synchronization with the switching circuit.

2. The circuit of claim 1, wherein the switching signal comprises a pulse-width modulated (PWM) signal, and the switch is configured to be controlled by the PWM signal.

3. The circuit of claim 1, wherein the switch is coupled between the pass transistor and the supply voltage.

4. The circuit of claim 1, wherein the switch is coupled between the pass transistor and the switching circuit.

5. The circuit of claim 1, wherein the switching circuit comprises one of a charge pump (CP) or a time-to-digital converter (TDC) circuit.

6. The circuit of claim 1, wherein the synchronous switching regulator circuit comprises a synchronous low dropout (LDO) switching regulator circuit.

7. The circuit of claim 1, further comprising a charge holding capacitor coupled between an output node of the synchronous switching regulator circuit connected to the switching circuit and a ground potential.

8. The circuit of claim 1, wherein the switch is operable to reduce supply ringing and fluctuation caused by load modulation of the synchronous switching regulator circuit.

9. The circuit of claim 1, further comprising an amplifier configured to drive the pass transistor and to control a current of the pass transistor based on a difference between an output voltage of the pass transistor and a reference voltage.

10. A wireless communication device, the device comprising:

a phased lock loop (PLL) including a switching circuit; and

a synchronous switching regulator configured to supply an operating voltage to the switching circuit,

wherein;

the synchronous switching regulator comprises;

a pass transistor configured to couple a voltage supply to the switching circuit; and

a switch operable to control a flow of a supply current through the pass transistor to the switching circuit based on a switching signal, wherein the switching circuit is configured to be controlled by the switching signal.

11. The device of claim 10, wherein the switch is coupled between the pass transistor and a voltage supply.

12. The device of claim 10, wherein the switch is coupled between the pass transistor and the switching circuit.

13. The device of claim 10, wherein the switching circuit comprises one of a charge pump (CP) or a time-to-digital converter (TDC) circuit.

14. The device of claim 10, wherein the switching signal comprises a pulse-width modulated (PWM) signal, and the switch is configured to be controlled by the PWM signal.

15. The device of claim 10, further comprising coupling a charge holding capacitor between an output node of the synchronous switching regulator circuit connected to the switching circuit and a ground potential.

16. The device of claim 10, wherein the switch is operable to reduce load modulation effects on synchronous switching regulator circuit and to reduce noise.

17. A method of providing a synchronous switching regulator circuit, the method comprising:

providing a pass transistor to couple a switching circuit to a supply voltage;

providing a switch;

configuring the switch to be controlled by the switching signal to operate in synchronization with the switching circuit and to turn off a flow of a supply current through the pass transistor in response to a switching signal; and

configuring the switching circuit to switch in response to the switching signal.

18. The method of claim 17, further comprising coupling the switch between the pass transistor and the supply voltage.

19. The method of claim 17, further comprising coupling the switch between the pass transistor and the switching circuit.

20. The method of claim 17, further comprising coupling a charge holding capacitor between an output node of the synchronous switching regulator circuit connected to the switching circuit and a ground potential.