Always-on low-dropout (LDO) regulator for coin-cell-based wireless local area network (WLAN) device
AssigneeQUALCOMM Incorporated
InventorSunghyun Park
Life of this patent
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Abstract
Techniques and apparatus for operating an always-on low-dropout (LDO) voltage regulator during cold boot and different sleep mode scenarios for a device including the LDO regulator. The LDO regulator may be disposed, for example, in a wireless local area network (WLAN) device powered by a coin cell battery. One example apparatus may be an integrated circuit (IC), which may be disposed in such a WLAN device and/or may be a power management unit (PMU). The IC generally includes a first port for coupling to a battery, a second port, a switched-mode power supply (SMPS) including a power supply input coupled to the second port, and an LDO regulator including a power supply input selectively coupled to the first port or to an output of the SMPS.
Claims26
An integrated circuit (IC) for power management, the IC comprising:
- a first port for coupling to a battery;
- a second port different than the first port;
- a switched-mode power supply (SMPS) including a power supply input coupled to the second port;
- a low-dropout (LDO) regulator including a power supply input selectively coupled to the first port or to an output of the SMPS;
- and
- a switch including a first terminal coupled to the first port, a second terminal coupled to the output of the SMPS, and a third terminal coupled to the power supply input of the LDO regulator, wherein the switch is configured to selectively couple the first terminal or the second terminal to the third terminal and wherein during a cold boot of the IC, the switch is configured to couple the first terminal to the third terminal, such that the LDO regulator is configured to be powered by the battery.
An integrated circuit (IC) for power management, the IC comprising:
- a first port for coupling to a battery;
- a second port different than the first port;
- a switched-mode power supply (SMPS) including a power supply input coupled to the second port;
- a low-dropout (LDO) regulator including a power supply input selectively coupled to the first port or to an output of the SMPS;
- a transistor;
- and
- a switch including a first terminal coupled to a source of the transistor and a second terminal coupled to a drain of the transistor, wherein to enter a sleep mode of the IC, when an output voltage from the SMPS is available, the power supply input of the LDO regulator is coupled to the output of the SMPS, the switch is configured to be closed to bypass the transistor, and the LDO regulator is configured to be disabled.
An integrated circuit (IC) for power management, the IC comprising:
- a first port for coupling to a battery;
- a second port different than the first port;
- a switched-mode power supply (SMPS) including a power supply input coupled to the second port;
- a low-dropout (LDO) regulator including a power supply input selectively coupled to the first port or to an output of the SMPS;
- a first transistor having a source coupled to the first port and having a drain coupled to an output of the LDO regulator;
- a second transistor having a source coupled to the first port and having a drain coupled to the output of the LDO regulator;
- a first comparator having a first input coupled to a first reference voltage node and having a second input coupled to the output of the LDO regulator;
- first logic coupled between an output of the first comparator and a gate of the first transistor;
- a second comparator having a first input coupled to a second reference voltage node and having a second input coupled to the output of the LDO regulator, wherein the first reference voltage node is configured to have a higher voltage than the second reference voltage node;
- and
- second logic coupled between an output of the second comparator and a gate of the second transistor.
A method for managing power in an integrated circuit (IC) comprising a low-dropout (LDO) regulator and a switched-mode power supply (SMPS), the method comprising:
- during a cold boot of the IC, coupling a power supply input of the LDO regulator to a battery input of the IC, such that the LDO regulator is powered by a battery for the cold boot;
- and
- after the cold boot of the IC, coupling the power supply input of the LDO regulator to an output of the SMPS, such that the LDO regulator is powered by the SMPS.
Dependencies are inferred from the claim text.