P9038-RNDGI datasheet(11/18 Pages) IDT

11 / 18 page

P9038 DATASHEET

P9038 August 1, 2016

The P9038 monitors the VBUS_SNS pin for over-voltage

conditions and shuts off the OVP MOSFET to implement

over-voltage protection. This OVP threshold can be

configured via a single pin as shown in Table 6.

Table 6: VBUS OVP Threshold Selection

A secondary over voltage protection with a 9.5V threshold is

implemented on REG_IN for cases where the OVP MOSFET

is not used. If the REG_IN threshold is exceeded, the P9038

is disabled until the REG_IN voltage drops below 8V.

Demodulation

Power transfer from the P9038 to a WPC-compliant wireless

power receiver, such as P9025AC-R, is controlled by the

receiver. Communication packets are superimposed on the

power link between the two devices, and are demodulated by

the P9038. Further information about the WPC

communication protocol can be found at the WPC website.

Communication can be made more robust by running traces

from Shield1 and Shield2 along both sides of the HPF trace.

Analog-to-Digital Converter [ADC]

The ADC is the main functional block which the MCU uses for

IC operation, including Foreign Object Detection. The ADC

also digitizes several internal and external voltages and

currents for overall system control and improved

demodulation functionality.

USB DP/DM Functionality

The P9038 implements USB D+/D- detection derived from the

BCS1.2 specification. This determines whether the USB

power source is a Standard Port (such as from a computer) or

a dedicated USB power supply Charger Port. When a Charger

Port is detected, the P9038 will set its GPIO-5 pin to a

logic-high state to indicate power is from a Charger Port. This

information may be used for any purpose, but has no direct

effect on the actual operation of the P9038.

Operation of the P9038 follows the commonly accepted

practice in wireless charging to draw as much power as the

source will allow. A Charger Port will provide its rated output,

which is usually greater than the normal 500mA limit that

could be typically expected from a Standard Port.

Foreign Object Detection and Input

Over-current Protection

The P9038 makes precision measurements of the input

voltage and input current, which are sampled by the internal

ADC and processed in firmware for WPC 1.2.2 Foreign Object

Detection [FOD] compliance. Two external pins, ISNS_AVG

and VSNS_AVG, are provided for filtering the input current

sense and input voltage sense signals respectively.

The input current sense signal is generated differentially from

the ISNSP_IN and ISNSN_IN pins. This input current sense

signal is filtered by an internal 50k

 output resistor combined

with an external capacitor on the ISNS_AVG pin.

Input voltage measurements are also filtered by an internal

33k

 output resistor on the VSNS_AVG pin combined with an

external capacitor on the VSNS_AVG pin. It is recommended

to follow approximately the filter time constants used on the

VSNS_AVG and ISNS_AVG signals as shown in the

reference design to insure time alignment of the resulting

measurements and accurate power calculation for FOD and

other purposes.

External Chip Reset and EN

The P9038 can be externally reset by pulling the RESET pin

to a logic high (above the VIH level).

The RESET pin is a dedicated high-impedance active-high

digital input, and its effect is similar to the automatic power-up

reset function. Because of the internal low voltage monitoring/

reset scheme, the use of the external RESET pin is not

mandatory. When RESET is HIGH, the micro-controller's

registers are set to the default configuration. When the

RESET pin is released to a LOW, the micro-controller starts

loading and executing the firmware from the program memory.

If the particular application requires the P9038 to be disabled,

this can be accomplished with the EN pin.

When the EN pin is pulled high, the device is shuts off and

placed in a very low current condition.When EN is connected

to logic LOW, the device will become active, and the

micro-controller starts loading and executing the firmware

from the program memory.

The current into EN is approximately equal to:

or close to zero if V(EN) is less than 2V.

OVP_SEL Pin Connection

OVP threshold

220kΩ to ground

6.3V

Grounded

7.15V

Floating

7.85V

–

300K

-------------------

P9038-RNDGI Datasheet(PDF) 11 Page - Integrated Device Technology

P9038-RNDGI Datasheet(HTML) 11 Page - Integrated Device Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Datasheet Descarga

Enlace URL