Controlled power switch chain sequencing for both power up and power down of a power domain
OwnerJose L. Flores, Sureshkumar Govendarajinventors
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Abstract
This invention makes the change in current drawn from the power grid in an integrated circuit gradual by sequencing the power switch chains differently for both power up and power down. During power up, this invention establishes a reasonable connection with the power grid through a series of weak power switches and then starts turning on the strong power switches. During power down, this invention reverses the process. Strong switches are all turned off before turning off the weak switches.
Claims4
A power control system for a power domain on an integrated circuit comprising:
- a power supply;
- a plurality of power switches, each having a first terminal connected to said power supply, a second terminal connected to a power supply input of the power domain and an input for control of conduction between said first terminal and said second terminal;
- and
- a power supply controller having a plurality of outputs, each output connected to said input of a corresponding power switch, said power supply controller operable to
- power up the power domain by supplying signals on said outputs to inputs of corresponding power switches to sequentially conduct via more and more power switches until all power switches conduct, and
- power down the power domain by supplying signals on said outputs to inputs of corresponding power switches to sequentially conduct via fewer and fewer power switches until no power switch conducts.
A method for supplying power to a power domain on an integrated circuit comprising the steps of:
- powering up the power domain by sequentially conducting more and more current until a maximum current is reached;
- and
- powering down the power domain by sequentially conducting via less and less current until no current is conducted.
Dependencies are inferred from the claim text.