Claims:1. An apparatus comprising:
one or more communication pins to couple to a charger external to the apparatus;
a first a power supply rail to couple to the charger;
a charger circuitry;
a second power supply rail coupled to the charger circuitry; and
a power delivery controller to detect connection of the charger to the apparatus via a pull-up or a pull-down termination impedance on the one or more communication pins, wherein the power delivery controller is to close a switch to couple the power supply rail with the second power supply rail in response to the detection of connection of the charger.
, Description:BACKGROUND
[0001] A Universal Serial Bus (USB) Type-C Power Consumer Sink, such as a mobile system-on-chip (SoC) host personal computer (PC) device, is expected to draw power less than or equal to a threshold power, pSnkStdby, during transitioning to a new VBUS Source voltage. The power delivery (PD) specification of the USB Type-C specifies this limit or threshold so an external source, such as wall charger, can manage the voltage transition while supplying minimal operating current for the platform. This reduces voltage overshoot transients and inrush current and avoid system shutdown while establishing power contract between the Sink and Source. Compliance of pSnkStdby power threshold during transitioning to a new VBUS Source voltage improves user experience by avoiding uneventful shutoff due to battery overload and thus extends battery life.
[0002] Mobile SoC host systems do not have a defined mechanism to control the SoC system power consumption during the Type-C Power contract or negotiation establishment. As such, user experience is worst when a Source, e.g., a charger, is connected to a system and booted with a dead battery condition. Peak power demand during boot sequence coupled with no battery power leads to platform resets many times during a boot process.

BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The embodiments of the disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure, which, however, should not be taken to limit the disclosure to the specific embodiments, but are for explanation and understanding only.
[0004] Fig. 1 illustrates a platform power delivery (PD) architecture, in accordance with some embodiments.
[0005] Fig. 2 illustrates a flowchart for stage 1 charge source port partner and host system-on-chip (SoC) sink PD and embedded controller (EC) interaction, in accordance with some embodiments.
[0006] Fig. 3 illustrates a flowchart for stage 2 charge source port partner and host SoC sink PD and EC interaction, in accordance with some embodiments.
[0007] Fig. 4 illustrates a smart device or a computer system or a SoC with improve power negotiation scheme, in accordance with various embodiments.

DETAILED DESCRIPTION
[0008] Currently there are no proper protocols or hardware interface implemented in mobile SoC host systems to reduce power consumption at or below the pSnkStdby power limit or threshold of the host system. A common usage case is for a user to find through a “Low Battery Indicator” that a charger should be connected to the mobile SoC host system. Usually the “Low Battery Indicator” has enough guard band to power the system when the charger is connected. At such time when the user connects to the external power source (e.g., a wall charger) and there is ongoing Type-C Power contract establishment or negotiation, the SoC host system consumes more power than the pSnkStdby power limit.