P9235A-R Datasheet

© 2016 Integrated Device Technology, Inc

13

May 17, 2016

using two narrow transitions. A logic ZERO bit is encoded using two wider transitions as shown in Figure 9.

Figure 9. Bit encoding scheme.

ONE

ZERO

ONE

ZERO

ONE

ONE

ZERO

ZERO

Each byte in the communication packet comprises 11 bits in an asynchronous serial format. The start bit is always LO. This is followed by 8

bits of data. The final two bits are parity and stop, as shown in Figure 10.

Figure 10. Byte encoding scheme.

Start

Stop

Parity

b

0

1

2

3

4

5

6

7

b

b

b

b

b

b

b

The wireless power receiver communicates with the wireless power transmitter via communication packets. Each communication packet has

the following structure:

Figure 11. Communication packet structure

Preamble

Header

Message

Checksum

LED Pattern Selection

A green LED and a red LED indicate status. The LED Patterns depend on the selected LED mode. The voltage applied through resistor

divider to the LED_PAT pin selects the desired LED mode. Table 8 shows the available selections. Note that the LED pin selection is

combined with the input current sense resistor. Pulling the LED_PAT pin to GND via a 47 kΩ resistor will set the LED pattern to the default

Mode 1.