Voltage switching system for integrated circuit

• US 9,343,966 B1
• Filed: 03/02/2015
• Issued: 05/17/2016
• Est. Priority Date: 03/02/2015
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Thakur, Nishant Singh
• Primary Examiner(s): Tran, Nguyen
• Application Number:
  US14/635,891
• Time in Patent Office: 442 Days
• Field of Search: 323223-225, 323/249, 323/251, 323/265, 323/266, 323/268, 323/350, 323311-317, 713/300, 713/310, 713/320, 713/324, 713/330, 713/340
• US Class Current: 1/1
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A voltage switching system for an integrated circuit (IC) operable in first and second operational modes includes a handover module, first and second voltage regulators, a switch driver, a transistor, and a comparator. When the IC transitions between modes, the handover module receives ramp control and hand-over start signals, generates comparator and bandwidth control signals based on the hand-over start signal and a ramp signal based on the ramp control signal. The switch driver generates a power control signal based on the comparator control signal and a gate input signal based on the ramp signal. The comparator compares first and second voltage signals based on the power control signal and generates a hand-over complete signal. The handover module generates a final hand-over complete signal based on the hand-over complete signal, indicative of completion of transition between the first and second operational modes.

Claims

1. A voltage switching system connected to an integrated circuit (IC), wherein the IC is operable in first and second operational modes, the voltage switching system comprising:

a handover module for receiving ramp control and handover start signals and a first voltage signal, generating first and second reference voltage signals, generating bandwidth control and comparator control signals based on the handover start signal, and a ramp signal based on the ramp control signal, and setting a voltage level of the second reference voltage signal based on the handover start signal and the first voltage signal;

a first voltage regulator having a first input terminal connected to the handover module for receiving the first reference voltage signal, a second input terminal for receiving the first voltage signal, and an output terminal connected to the handover module for generating the first voltage signal based on the first reference voltage signal when the IC is in the first operational mode and when the IC transitions between the first and second operational modes, wherein the first voltage regulator is switched off when the IC is in the second operational mode;

a second voltage regulator having a first input terminal connected to the handover module for receiving the second reference voltage signal, a second input terminal for receiving a second voltage signal, a third input terminal connected to the handover module for receiving the bandwidth control signal, and an output terminal for generating the second voltage signal based on the second reference voltage signal when the IC is in the first and second operational modes and when the IC transitions between the first and second operational modes;

a switch driver connected to the handover module for receiving the comparator control signal and the ramp signal, and for generating a power control signal based on the comparator control signal, and a gate input signal based on the ramp signal;

a transistor having a source terminal connected to the output terminal of the first voltage regulator for receiving the first voltage signal, a gate terminal connected to the switch driver for receiving the gate input signal, and a drain terminal connected to the output terminal of the second voltage regulator for receiving the second voltage signal; and

a comparator having a first input terminal connected to the source terminal of the transistor for receiving the first voltage signal, a second input terminal connected to the drain terminal of the transistor for receiving the second voltage signal, a third input terminal connected to the switch driver for receiving the power control signal, wherein the comparator compares the first and second voltage signals based on the power control signal, determines a voltage difference between the first and second voltage signals, and generates a handover complete signal at an output terminal thereof based on the voltage difference.

2. The voltage switching system of claim 1, wherein the handover module generates the bandwidth control and comparator control signals at a first logic state based on the handover start signal, and wherein the handover start signal is indicative of transition of the IC between the first and second operational modes.

3. The voltage switching system of claim 2, wherein the handover module is further connected to the output terminal of the comparator, and receives the handover complete signal, generates a final handover complete signal based on the handover complete signal indicative of completion of transition of the IC between the first and second operational modes, and generates the comparator control and bandwidth control signals at a second logic state based on the handover complete signal.

4. The voltage switching system of claim 3, wherein the second voltage regulator increases an operational bandwidth thereof when the bandwidth control signal is at the first logic state, and wherein the second voltage regulator decreases the operational bandwidth when the bandwidth control signal is at the second logic state.

5. The voltage switching system of claim 4, wherein the switch driver receives the comparator control signal and generates the power control signal at the first logic state when the comparator control signal is at the first logic state, and generates the power control signal at the second logic state when the comparator control signal is at the second logic state.

6. The voltage switching system of claim 5, wherein the comparator stops comparing the first and second voltage signals when the power control signal is at the second logic state.

7. The voltage switching system of claim 4, wherein the handover module further generates the second reference voltage signal at an intermediate reference voltage level based on the handover start signal and the first voltage signal, and at a final reference voltage level based on the handover complete signal, wherein the final reference voltage level is less than a voltage level of the first voltage signal.

8. The voltage switching system of claim 7, wherein the second voltage regulator regulates the second voltage signal at the intermediate reference voltage level when the bandwidth control signal is at the first logic state and regulates the second voltage signal at the final reference voltage level when the bandwidth control signal is at the second logic state.

9. The voltage switching system of claim 7, wherein the intermediate reference voltage level is higher than the voltage level of the first voltage signal when the IC transitions from the first to the second operational mode.

10. The voltage switching system of claim 7, wherein the intermediate reference voltage level is less than the voltage level of the first voltage signal when the IC transitions from the second to the first operational mode.

11. An integrated circuit (IC) operable in first and second operational modes, comprising:

a first domain that receives a first voltage signal, wherein the first domain is operable when the IC is in the first operational mode and when the IC transitions between the first and second operational modes, and wherein the first domain is switched off when the IC is in the second operational mode;

a second domain that receives a second voltage signal, wherein the second domain is operable when the IC is in the first and second operational modes and when the IC transitions between the first and second operational modes;

a handover module for receiving ramp control and handover start signals and the first voltage signal, generating first and second reference voltage signals, generating bandwidth control and comparator control signals based on the handover start signal, and a ramp signal based on the ramp control signal, and setting a voltage level of the second reference voltage signal based on the handover start signal and the first voltage signal;

a first voltage regulator having a first input terminal connected to the handover module for receiving the first reference voltage signal, a second input terminal for receiving the first voltage signal, and an output terminal connected to the handover module for generating the first voltage signal based on the first reference voltage signal when the IC is in the first operational mode and when the IC transitions between the first and second operational modes, wherein the first voltage regulator is switched off when the IC is in the second operational mode;

a second voltage regulator having a first input terminal connected to the handover module for receiving the second reference voltage signal, a second input terminal for receiving the second voltage signal, a third input terminal connected to the handover module for receiving the bandwidth control signal, and an output terminal for generating the second voltage signal based on the second reference voltage signal when the IC is in the first and second operational modes and when the IC transitions between the first and second operational modes;

a switch driver connected to the handover module for receiving the comparator control signal and the ramp signal, for generating a power control signal based on the comparator control signal, and for generating a gate input signal based on the ramp signal;

a transistor having a source terminal connected to the output terminal of the first voltage regulator for receiving the first voltage signal, a gate terminal connected to the switch driver for receiving the gate input signal, and a drain terminal connected to the output terminal of the second voltage regulator for receiving the second voltage signal; and

a comparator having a first input terminal connected to the source terminal of the transistor for receiving the first voltage signal, a second input terminal connected to the drain terminal of the transistor for receiving the second voltage signal, a third input terminal connected to the switch driver for receiving the power control signal, wherein the comparator compares the first and second voltage signals based on the power control signal, determines a voltage difference between the first and second voltage signals, and generates a handover complete signal at an output terminal thereof based on the voltage difference.

12. The IC of claim 11, wherein the handover module generates the bandwidth control and comparator control signals at a first logic state based on the handover start signal, and wherein handover start signal is indicative of transition of the IC between the first and second operational modes.

13. The IC of claim 12, wherein the handover module is further connected to the output terminal of the comparator for receiving the handover complete signal, for generating a final handover complete signal based on the handover complete signal indicative of completion of transition of the IC between the first and second operational modes, and generating the comparator control and bandwidth control signals at a second logic state based on the handover complete signal.

14. The IC of claim 13, wherein the second voltage regulator increases an operational bandwidth thereof when the bandwidth control signal is at the first logic state, and wherein the second voltage regulator decreases the operational bandwidth when the bandwidth control signal is at the second logic state.

15. The IC of claim 14, wherein the switch driver receives the comparator control signal and generates the power control signal at the first logic state when the comparator control signal is at the first logic state, and generates the power control signal at the second logic state when the comparator control signal is at the second logic state.

16. The IC of claim 15, wherein the comparator stops comparing the first and second voltage signals when the power control signal is at the second logic state.

17. The IC of claim 14, wherein the handover module further generates the second reference voltage signal at an intermediate reference voltage level based on the handover start signal and the first voltage signal and at a final reference voltage level based on the handover complete signal, wherein the final reference voltage level is less than a voltage level of the first voltage signal.

18. The IC of claim 17, wherein the second voltage regulator regulates the second voltage signal at the intermediate reference voltage level when the bandwidth control signal is at the first logic state and regulates the second voltage signal at the final reference voltage level when the bandwidth control signal is at the second logic state.

19. The IC of claim 17, wherein the intermediate reference voltage level is higher than the voltage level of the first voltage signal when the IC transitions from the first to the second operational mode.

20. The IC of claim 17, wherein the intermediate reference voltage level is less than the voltage level of the first voltage signal when the IC transitions from the second to the first operational mode.