09/01/15

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5W, QI WIRELESS POWER RECEIVER WITH INTEGRATED RECTIFIER AND LDO OUTPUT

P9025AC DATASHEET

Status Output

The STAT output goes low when the LDO output is enabled.

Interrupt Output

The INT output goes low to indicate that an Over-Current,

Over-Voltage or Over-Temperature event has occurred. See

the Electrical Specifications for threshold levels.

Enable Input

If the particular application requires the P9025AC to be

disabled, this can be accomplished with the EN pin. When the

EN pin is pulled high, the device is suspended and placed in

low current (sleep) mode. If the EN pin is pulled low or floating,

the device is active.

TEOP Input

The P9025AC can optionally be shut down with the TEOP pin.

This pin is typically used to shut down the P9025AC if the

battery charger or host system determines an over-limit high

temperature condition. When the TEOP pin is pulled high, the

P9025AC will disable its LDO output, and also send an

End-of-Power packet to the transmitter with code 0x03

(Over-Temperature code). In response to the End-of-Power

packet, the transmitter will immediately stop power transfer

and go into a sleeping (no power offered) condition for some

period of time. The amount of sleep time is not prescribed by

WPC and varies among different transmitters. A common

value used for this over-temperature sleep time is

approximately 5-minutes.

CHG_END / CS100

This pin has two functions. The Charge-End default function

can be used to terminate power transfer with the transmitter.

When CHG_END is pulled high, the P9025AC will send a

WPC End-of-Charge packet with a code value of 0x01

(Charge Complete code). In response to this, the transmitter

should immediately stop power transfer and go into a sleeping

(no power offered) condition for some period of time. The

amount of sleep time is not prescribed by WPC and varies

from 5-seconds to much longer, depending on the transmitter

design.

If the pin is set in Charge-Status mode, the device will send a

WPC Charge Status packet with value 100 (100% charge)

indicating a fully charged battery.

LDO

The primary output of the P9025AC device is a linear regulator

the system and/or charging circuitry. The output provides a

nominal 5.3V with 1 A output current capability. The voltage is

intentionally set 0.3V higher than the standard 5V rail to

provide extra headroom for voltage drops that may be

encountered in the system under heavy loads.

Modulation/Communication

Receiver-to-transmitter communication is accomplished by

modulating the load seen by the receiver's inductor. To the

transmitter, this appears as an impedance change, which

results in measurable variations of the transmitter's output

waveform. Modulation is done with AC Modulation, using

internal switches to connect external capacitors from AC1 and

AC2 to ground. The communication protocol is covered in the

next section.

WPC Communication

The P9025AC communicates with the base via

communication packets. Each communication packet has the

following structure:

Figure 3. Communication Packet Structure

In accordance with the WPC specification, the power receiver

communicates with the power transmitter using load

modulation. The load seen by the power transmitter's inductor

is modulated on the receiver side in a periodic fashion to send

packets. The power transmitter detects this as a modulation of

coil current/voltage to receive the packet information.

7V

6.3V

5.5V

5.45V