SLIS146G June   2012  – September 2017 BQ24392

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Charger Detection
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Using the BQ24392 GPIOs
        1. 8.1.1.1 CHG_AL and CHG_DET
        2. 8.1.1.2 SW_OPEN
        3. 8.1.1.3 GOOD_BAT
        4. 8.1.1.4 Slow Plug-in Event
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
  12. 12Mechanical, Packaging, and Orderable Information

7 Detailed Description

7.1 Overview

The BQ24392 is a USB 2.0 high-speed isolation switch with charger detection capabilities for use with micro and mini-USB ports. Upon plugin of a Battery Charging Specification 1.2 (BCv1.2) compliant, Apple™, TomTom™, or other USB charger into a micro or mini-USB connector, the device will automatically detect the charger and operate the USB 2.0 high-speed isolation switch.

The BQ24392 device is powered through VBUS when a charger is attached to the micro or mini-USB port and has a 28-V tolerance to avoid the need for external protection.

7.2 Functional Block Diagram

BQ24392 fbd_slis146.gif

7.3 Feature Description

7.3.1 Charger Detection

BQ24392 chg_det_slis146.gif Figure 3. Charge Detection Block Diagram

When a micro or mini-USB accessory is inserted into the connector and once VBUS is greater than VVBUS_VALID threshold, the BQ24392 will enter into the Data Contact Detection (DCD) state which includes a 600-ms timeout feature that is prescribed in the USB Battery Charging Specification version 1.2 (BCv1.2). If the micro or mini-USB accessory is determined to be USB BCv1.2 compliant, a 130-ms debounce period will initiate and the BQ24392 will proceed to its primary detection and then secondary detection states to determine if a Dedicated Charging Port (DCP), Standard Downstream Port (SDP), or Charging Downstream Port (CDP) is attached to the USB-port. The minimum detection time for a DCP, SDP, and CDP is 130 ms, but can be as long as 600 ms due to the slow plug in effect.

If the GOOD_BAT pin is high, the USB 2.0 switches are automatically closed to enable data transfer after the device detects a Standard Downstream Port (SDP) or Charging Downstream Port (CDP) was connected.

If Data Contact Detection (DCD) fails, the BQ24392 proceeds to detect whether an Apple or TomTom charger was inserted by checking the voltage level on DP_CON and DM_CON. Thus, for Apple and TomTom chargers, detection time typically takes ~600 ms.

The 3 output pins CHG_AL_N, CHG_DET, and SW_OPEN change their status at the end of detection. Table 1 is the detection table with the GPIO status for each type of supported charger. More information on how to use the GPIOs is available in Using the BQ24392 GPIOs .

Table 1. Detection Table

Device Type VBUS DP_CON
(D+)		 DM_CON
(D–)		 GOOD_BAT
(Input)		 CHG_AL_N
(Output)		 CHG_DET
(Output)		 SW_OPEN
(Output)		 Switch Status Charge Current
Standard
Downstream Port		 > 3.5 V Pull-down R to GND Pull-down R to GND HIGH LOW LOW LOW Connected Charge with 100 mA/ Change the input current based on enumeration
LOW LOW LOW High-Z Not Connected Charge with 100 mA
Charging
Downstream Port		 > 3.5 V Pull-down R to GND VDM_SRC HIGH LOW HIGH LOW Connected Charge with full current
LOW LOW HIGH High-Z Not Connected Charge with 100 mA
Dedicated
Charging Port		 > 3.5 V Short to D– Short to D+ X LOW HIGH High-Z Not Connected Charge with full current
Apple Charger > 3.5 V 2.0 < VDP_CON < 2.8 2.0 < VDM_CON < 2.8 X LOW HIGH High-Z Not Connected Charge with full current
TomTom Charger > 3.5 V 2.0 < VDP_CON < 3.1 2.0 < VDM_CON < 3.1 X LOW HIGH High-Z Not Connected Charge with full current
PS/2 Charger > 3.5 V Pull-up R to VVBUS Pull-up R to VVBUS X LOW LOW High-Z Not Connected Charge with 100 mA
Non-compliant
USB Charger		 > 3.5 V Open Open X LOW LOW High-Z Not Connected Charge with 100 mA
Any Device < 3.5 V Open Open X High-Z LOW High-Z Not Connected No Charge
Any Device DBP
Timer Expired		 > 3.5 V X X LOW High-Z LOW High-Z Not Connected No Charge

If a charge has been detected and the GOOD_BAT pin is low, a Dead Battery Provision (DBP) timer is initiated. If the GOOD_BAT continues to be low for 30 minutes (maximum of 45 minutes), charging is disabled and CHG_AL_N goes into the High-Z state to indicate this. Toggling GOOD_BAT high after the DBP timer expires re-starts detection and the DBP timer.

7.4 Device Functional Modes

The BQ24392 has two functional modes USB switch ON and USB switch OFF.