ZHCSGF6A April   2017  – July 2017 TPD2S701-Q1

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
  4. 修订历史
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings—AEC Specification
    3. 6.3  ESD Ratings—IEC Specification
    4. 6.4  ESD Ratings—ISO Specification
    5. 6.5  Recommended Operating Conditions
    6. 6.6  Thermal Information
    7. 6.7  Electrical Characteristics
    8. 6.8  Power Supply and Supply Current Consumption Chracteristics
    9. 6.9  Timing Requirements
    10. 6.10 Typical Characteristics
  7. Parameter Measurement Information
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 OVP Operation
      2. 8.3.2 OVP Threshold
      3. 8.3.3 D± Clamping Voltage
    4. 8.4 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Device Operation
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 VREF Operation
          1. 9.2.2.1.1 Mode 0
          2. 9.2.2.1.2 Mode 1
        2. 9.2.2.2 Mode 1 Enable Timing
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 VPWR Path
    2. 10.2 VREF Pin
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 文档支持
      1. 12.1.1 相关文档
    2. 12.2 接收文档更新通知
    3. 12.3 社区资源
    4. 12.4 商标
    5. 12.5 静电放电警告
    6. 12.6 Glossary
  13. 13机械、封装和可订购信息

Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

Application Information

The TPD2S701-Q1 offers 2-channels of short-to-VBUS protection and IEC ESD protection for automotive high speed interfaces such as USB 2.0. For the overvoltage protection (OVP), this device integrates N-channel FET’s which quickly isolate (200 ns) the protected circuitry in the event of an overvoltage condition on the VD+ and VD– lines. With respect to the ESD protection, the TPD2S701-Q1 has an internal clamping diode on each data line (VD+ and VD–) which provides 8-kV contact ESD protection and 15-kV air-gap ESD protection. More details on the internal components of the TPD2S701-Q1 can be found in the Overview section.

The TPD2S701-Q1 also has the ability to vary the OVP threshold based on the configuration of the Mode pin and the voltage present on the VREF pin (0.6 V-4.5 V). This functionality is discussed in greater depth in the OVP Threshold section. Once the VREF threshold is crossed, a fault is detectable to the user through the FLT pin, where 5 V on the pin indicates no fault is detected, and 0 V-0.4 V represents a fault condition. Figure 21 shows the TPD2S701-Q1 in a typical application, interfacing between the protected internal circuitry and the connector side, where ESD vulnerability is at its highest.

Typical Application

TPD2S701-Q1 USB2_0_Port_Short_to_Battery_1_701.gif Figure 21. USB 2.0 Port With Short-to-VBUS and IEC ESD Protection

Design Requirements

Device Operation

Table 1 gives the complete device functionality in response to the EN pin, to overvoltage conditions at the connector (VD± pins), to thermal shutdown, and to the conditions of the VPWR, VREF, and MODE pins.

Table 1. Device Operation Table

Functional Mode EN MODE VREF VPWR VD± TJ FLT Comments
NORMAL OPERATION
Mode 0 unpowered 1 X Rbot ≤ 2.6 kΩ X X X X H Device unpowered, data switches open
Mode 0 unpowered 2 X Rbot ≤ 2.6 kΩ X X X X H Device unpowered, data switches open
Mode 1 unpowered X Rtop | | Rbot > 14 kΩ X X X X H Device unpowered, data switches open
Mode 0 disabled H Rbot ≤ 2.6 kΩ >UVLO >UVLO X <TSD H Device disabled, data switches open
Mode 1 disabled H Rtop | | Rbot > 14 kΩ Set by Rtop and Rbot >UVLO X <TSD H Device disabled, data switches open, VREF is disabled
Mode 0 enabled L Rbot ≤ 2.6 kΩ >UVLO >UVLO <OVP <TSD H Device enabled, data switches closed, VREF is the value set by the power supply on VREF
Mode 1 enabled L Rtop | | Rbot > 14 kΩ Set by Rtop and Rbot >UVLO <OVP <TSD H Device enabled, data switches closed, VREF is the value set by the Rtop and Rbot resistor divider
FAULT CONDITIONS
Mode 0 thermal shutdown X Rbot ≤ 2.6 kΩ X >UVLO X >TSD L Thermal shutdown, data switches opened, FLT pin asserted
Mode 1 thermal shutdown X Rtop | | Rbot > 14 kΩ Set by Rtop and Rbot >UVLO X >TSD L Thermal shutdown, data switches opened, VREF is disabled, FLT pin asserted
Mode 0 OVP fault L Rbot ≤ 2.6 kΩ >UVLO >UVLO >OVP <TSD L Data line overvoltage protection mode. OVP is set relative to the voltage on VREF. Data switches opened, FLT pin asserted
Mode 1 OVP fault L Rtop | | Rbot > 14 kΩ Set by Rtop and Rbot >UVLO >OVP <TSD L Data line overvoltage protection mode. OVP is set relative to the voltage on VREF. Data switches opened, fault pin asserted

Detailed Design Procedure

VREF Operation

The TPD2S701-Q1 has two modes of operation which vary the way the VREF pin functions. In Mode 0, the VREF pin is connected to an external regulator which sets the voltage on the VREF pin. In Mode 1, the TPD2S701-Q1 uses an adjustable internal regulator to set the VREF voltage. Mode 1 enables the system designer to operate the TPD2S701-Q1 with a single power supply, and have the flexibility to easily set the VREF voltage to any voltage between 0.6 V and 3.8 V with two external resistors.

Mode 0

To set the device into Mode 0, ensure that Rbot, resistance between the MODE pin and ground, is less than 2.6 kΩ. The easiest way to implement Mode 0 is to directly connect the mode pin to GND on your PCB. With this resistance condition met, connect VREF to an external regulator to set the VREF voltage.

Mode 1

To operate in Mode 1, ensure that Rtop || Rbot, resistance between the MODE pin and ground, is greater than 14 kΩ. This is accomplished by insuring Rtop || Rbot > 14 kΩ because when the device is initially powered up, VREF is at ground until the internal circuitry recognizes if the device is in Mode 1 or Mode 2.

In Mode 1, VREF is set by using an internal regulator to set the voltage. Using a resistor divider off of a feedback comparator is how to set VREF, similar to a standard LDO or DC/DC. VREF is set in Mode 1 according to Equation 5.

Equation 5. TPD2S701-Q1 Equation_1.gif

Equation 5 yields the typical value for VREF. When using ±1% resistors RTOP and RBOT, VREF accuracy is going to be ±5%. Therefore, the minimum and maximum values for VREF can be calculated off of the typical VREF. The parametric tables above give example RTOP and RBOT resistors to use for standard output VREF voltages for Mode 1.

Mode 1 Enable Timing

In Mode 1, when the TPD2S701-Q1 is disabled, the output regulator is disabled, leading VREF to discharge to 0 V through RTOP and RBOT. It is desired for VREF to be at 0 V when the device is disabled to minimize the clamping voltage during a power disabled ESD event. If VREF is at 0 V, this holds D± near ground during these fault events.

When enabling the TPD2S701-Q1, VREF is quickly charged up to insure a quick turnon time of the Data FETs. Data FET turnon is gated by VREF reaching 80% of its final voltage plus 150 µs to insure a proper OVP threshold is set before passing data. This prevents false OVPs due to normal operation. Because Data FET turnon is gated by charging the VREF clamping capacitor, the size of the capacitor influences the turnon time of the Data switches. The TPD2S701-Q1’s internal regulator uses a constant current source to quickly charge the VREF clamping capacitor, so the charging time of CVREF can easily be calculated with Equation 6.

Equation 6. TPD2S701-Q1 Equation_2.gif

Where CVREF is the clamping capacitance on VREF, VREFFINAL is the final value VREF is set to, and ICHG_VREF = 22 mA (typical). If VREF = 1 V, 0.8 is used in the above equation because 80% of VREF is the amount of time that gates the turnon of the Data FETs. Once tCHG_CVREF is calculated, the typical turnon time of the Data FETs can be calculated from Equation 7.

Equation 7. TPD2S701-Q1 Mode_Enable_Equation_4.gif

Application Curves

TPD2S701-Q1 D018_SLLSEU8.gif
Figure 22. USB2.0 Eye Diagram (Board Only, Through Path)
TPD2S701-Q1 D019_SLLSEU8.gif
Figure 23. USB2.0 Eye Diagram (System from Typical Application Schematic)