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Transmitter
the Power Transmitter proceeds to the ping phase—and eventually to the power transfer phase. If the
Power Transmitter does not select a Power Receiver for power transfer—and is not actively providing
power to a Power Receiver for an extended amount of time—the Power Transmitter enters a stand-by
mode of operation.
Ping
In this phase, the Power Transmitter executes a Digital Ping, and listens for a response. If the Power
Transmitter discovers a Power Receiver, the Power Transmitter may extend the Digital Ping, i.e. maintain
the Power Signal at the level of the Digital Ping. This causes the system to proceed to the identification &
configuration phase. If the Power Transmitter does not extend the Digital Ping, the system shall revert to
the selection phase.
Identification & Configuration
In this phase, the Power Transmitter identifies the selected Power Receiver, and obtains configuration
information such as the maximum amount of power that the Power Receiver intends to provide at its
output. The Power Transmitter uses this information to create a Power Transfer Contract. This Power
Transfer Contract contains limits for several parameters that characterize the power transfer in the power
transfer phase. At any time before proceeding to the power transfer phase, the Power Transmitter may
decide to terminate the extended Digital Ping and returns the system to the selection phase.
Power Transfer
In this phase, the Power Transmitter continues to provide power to the Power Receiver, adjusting its
Primary Cell current in response to control data that it receives from the Power Receiver. Throughout this
phase, the Power Transmitter monitors the parameters that are contained in the Power Transfer Contract.
A violation of any of the stated limits on any of those parameters causes the Power Transmitter to abort
the power transfer—returning the system to the selection phase. Finally, the system may also leave the
power transfer phase on request of the Power Receiver. For example, the Power Receiver can request to
terminate the power transfer—battery fully charged—reverting the system to the selection phase, or
request to renegotiate the Power Transfer Contract—change to trickle charging the battery using a lower
maximum amount of power—reverting the system to the identification & configuration phase.
At any time a user can remove a Mobile Device that is receiving power. The Power Transmitter can
recognize such an event from a time-out in the communications from the Power Receiver, or from a
violation of the Power Transfer Contract. As a result, the Power Transmitter aborts the power transfer and
the system reverts to the selection phase.
© 2014 Copyright, Active-Semi International, Inc.
No portion of this document may be reproduced or reused in any form without Active-Semi's prior written consent
PAC5220WP A11 WPC
Power Application Controller
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Rev 1.7 May, 2014
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