P9412 Datasheet

R35DS0011EU0120 Rev.1.2

Jul.6.21

Page 19

Each byte has a start bit, 8 data bits, a parity bit, and a single stop bit.

3.13.7.

System Feedback Control

The P9412 is fully compatible with the WPC (latest specification), and has all necessary circuitry to communicate

with the base station or with a receiver via WPC communication packets. The overall WPC system behavior

between the transmitter and receiver follows the state machine shown below

.

Selection

Ping

Identification

& Configuration

Negotiation

EP

Calibration

EP

Renegotiation

EP

Power Transfer

No response

or no power

needed

Object

detected

Negotiation failure

or error condition

Calibration failure

or error condition

Negotiation

successful

Power receiver

present

Error

condition

Negotiation

requested

No negotiation requested

(≤ 5W power receiver only)

Power transfer complete

or error condition

START

Renegotiation

requested

Renegotiation

completed

Calibration

successful

Error

condition

Figure 10. WPC System Feedback Control

The P9412 goes through four phases: Selection, Ping, Identification & Configuration, Negotiation, Calibration

and Power Transfer.

3.13.8.

Selection

In this phase, the P9412 senses or delivers the wireless power and proceeds to the PING state. It monitors the

rectified voltage or DEMOD signal, and when the voltage is above the VUVLO_rising threshold, the P9412 prepares

to communicate with the base station or enter power PING mode.

3.13.9.

Ping

In this phase, the P9412 transmits a Signal Strength Packet as the first communication packet to instruct the

base to keep the power signal ON (or the P9412 detects a Signal Strength Packet). After sending/receiving the

Signal Strength Packet, the P9412 proceeds to the Identification and Configuration phase. If, instead, an End of

Power Packet is sent or an invalid response is sent, then it remains in the PING phase.

In this phase, the P9412 sends/expects the following packets:

•

Signal Strength Packet

•

End of Power Packet

3.13.10. Identification and Configuration (ID and Config)

In this phase, the P9412 sends or expect the following packets:

•

Identification Packet

•

Configuration Packet

After the transmission of the Configuration Packet, the P9412 proceeds to the Negotiation phase.