Power

control

interface

ADC

Controller

COMM2

bq500511

PWM2/UP_DN

SCL

SDA

PWM1/CLK_OUT

Status

indication

I2C

COMM1

Communication

input

TSENSE

VSENSE

ISENSE

LED_B

LED_A

VPEAK

LED_MODE

FOD_CAL

FOD_THR

BUZZ

LED_C

MODE

DRV_EN

PWM_CTRL

CLK_IN

bq500511

www.ti.com

SLUSCD3A – AUGUST 2015 – REVISED OCTOBER 2015

7 Detailed Description

7.1 Overview

The principle of wireless power transfer is simply an open-cored transformer consisting of transmitter and

receiver coils. The transmitter coil and electronics are typically built into a charger pad and the receiver coil and

electronics are typically built into a portable device, such as a cell phone. When the receiver coil is positioned on

the transmitter coil, magnetic coupling occurs when the transmitter coil is driven. The flux is coupled into the

secondary coil, which induces a voltage and current flows. The secondary voltage is rectified, and power can be

transferred effectively to a load, wirelessly. Power transfer can be managed through various closed loop control

schemes.

After power is applied and the transmitter device comes out of reset, it will automatically begin the process of

detecting and powering a receiver. The bq500511 sends a ping to detect the presence of a receiver on the pad.

After a receiver is detected, the bq500511 attempts to establish communication and begin power transfer. The

bq500511 is designed to operate with the bq50002 Wireless Power Transmitter Analog Front End to control a

full-bridge power stage to drive the primary coil. Through a simple interface the bq500511 instructs the bq50002

how much to increase or decrease power. The full bridge power stage allows for higher power delivery for a

given supply voltage.

7.2 Functional Block Diagram

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Product Folder Links: bq500511