DS1650 Datasheet, PDF (14/26 Pages) National Semiconductor (TI) – Quad Differential Line Receivers

RT1650
Functional Description
Description of the Wireless Power System
A wireless power system is composed by a power
transmitter with one or more primary coils and a power
receiver in a mobile system. Power transmitter will
transfer power via a DC-to-AC inverter to drive a
strong-coupled inductor to power receiver in a mobile
device.
The power transferred to power receiver is controlled
by itself. The power receiver sends communication
packets with control error voltage information to the
power transmitter for power tracking. The bit rate of the
communication link from receiver to transmitter is
2kbps.
Mobile Device
Load
Output
Power
Sensing&
Control
Sensing
Power Pick-up
Communications
Unit
Control _{& Control Unit}
Power
Conversion
Unit
Sensing
Communications
Control _{& Control Unit}
Input
Power
Sensing &
Control
System Unit
Base Station
Figure 1. Wireless Power System
Start-up
When the receiver is placed on the power pad, the
receiver coil is inductively coupled to the magnetic flux
generated by the coil in the power pad which
consequently induces a voltage in the receiver coil. The
internal synchronous rectifier feeds this voltage to the
RECT pin which has the filter capacitor. The RT1650
communicates to the transmitter by switching on and
off the COM FETs.
Power Transfer phases
There are 4 power transfer phases for the WPC V1.1.
 Selection : As soon as the Power Transmitter applies
a Power Signal, the Power Receiver shall enter the
selection phase.
 Ping : The power Receiver should send the Digital
Ping Packet to power Transmitter then into next
phase. If not, the system shall revert to the Selection
phase. The power Receiver also can send the End
Power transfer Packet to stop the power Transmitter.
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is a registered trademark of Richtek Technology Corporation.
DS1650-00 July 2015