ZHCSF07A March   2016  – January 2017 TLV62095

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用范围
  3. 3 说明
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommend 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 PWM Operation
      2. 7.3.2 Power Save Mode Operation
      3. 7.3.3 Low Dropout Operation (100% Duty Cycle)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enable (EN)
      2. 7.4.2 Soft Startup (SS) and Hiccup Current Limit During Startup
      3. 7.4.3 Voltage Tracking (SS)
      4. 7.4.4 Short Circuit Protection (Hiccup-Mode)
      5. 7.4.5 Output Discharge Function
      6. 7.4.6 Power Good Output
      7. 7.4.7 Undervoltage Lockout
      8. 7.4.8 Thermal Shutdown
      9. 7.4.9 Charge Pump (CP, CN)
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 1.8-V Output Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Output Filter
          3. 8.2.1.2.3 Inductor Selection
          4. 8.2.1.2.4 Input and Output Capacitor Selection
          5. 8.2.1.2.5 Setting the Output Voltage
        3. 8.2.1.3 Application Performance Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Consideration
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 开发支持
        1. 11.1.2.1 使用 WEBENCH® 工具定制设计方案
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 Glossary
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

8 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.

8.1 Application Information

The TLV62095 is a 4-A high frequency synchronous step-down converter optimized for small solution size, high efficiency and suitable for battery powered applications.

8.2 Typical Applications

8.2.1 1.8-V Output Converter

TLV62095 typ_app_TLV62095.gif Figure 7. TLV62095 Typical Application Circuit

8.2.1.1 Design Requirements

The design guideline provides a component selection to operate the device within the recommended operating conditions. For the typical application example, the following input parameters are used.

Table 2. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
Input voltage range 2.5 V to 5.5 V
Output voltage 1.8 V
Output ripple voltage < 30 mV
Output current rating 4 A

Table 3 shows the list of components for the Application Characteristic Curves.

Table 3. List of Components

REFERENCE DESCRIPTION MANUFACTURER
TLV62095 High efficiency step-down converter Texas Instruments
L1 Inductor: 1 µH Coilcraft XAL4020-102
C1, C2 Ceramic capacitor: 22 μF (6.3V, X5R, 0805)
C4, C5 Ceramic capacitor, 10 nF Standard
R1, R2, R3 Resistor Standard

8.2.1.2 Detailed Design Procedure

8.2.1.2.1 Custom Design With WEBENCH® Tools

Click here to create a custom design using the TLV62095 device with the WEBENCH® Power Designer.

  1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements.
  2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial.
  3. Compare the generated design with other possible solutions from Texas Instruments.

The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time pricing and component availability.

In most cases, these actions are available:

  • Run electrical simulations to see important waveforms and circuit performance
  • Run thermal simulations to understand board thermal performance
  • Export customized schematic and layout into popular CAD formats
  • Print PDF reports for the design, and share the design with colleagues

Get more information about WEBENCH tools at www.ti.com/WEBENCH.

8.2.1.2.2 Output Filter

The first step is the selection of the output filter components. To simplify this process, Table 4 outlines possible inductor and capacitor value combinations.

Table 4. Output Filter Selection

INDUCTOR VALUE [µH](3) OUTPUT CAPACITOR VALUE [µF](2)
10 22 2 x 22 100 150
0.47
1.0 √(1) √ √
2.2
(1) Typical application configuration. Other check mark indicates alternative filter combinations
(2) Capacitance tolerance and bias voltage de-rating is anticipated. The effective capacitance can vary by +20% and –50%.
(3) Inductor tolerance and current de-rating is anticipated. The effective inductance can vary by +20% and –30%.

8.2.1.2.3 Inductor Selection

The inductor selection is affected by several parameters like inductor ripple current, output voltage ripple, transition point into Power Save Mode, and efficiency. See Table 5 for typical inductors.

Table 5. Inductor Selection

INDUCTOR VALUE COMPONENT SUPPLIER(1) SIZE (LxWxH mm) Isat / DCR
1 µH Coilcraft XAL4020-102 4.0 x 4.0 x 2.1 8.75A / 13.2 mΩ
0.47 µH TOKO DFE322512C 3.2 x 2.5 x 1.2 5.9A / 21 mΩ
(1) See Third-Party Products disclaimer

In addition, the inductor has to be rated for the appropriate saturation current and DC resistance (DCR). The inductor needs to be rated for a saturation current as high as the typical switch current limit of 5.5A or according to Equation 5 and Equation 6. Equation 5 and Equation 6 calculate the maximum inductor current under static load conditions. The formula takes the converter efficiency into account. The converter efficiency can be taken from the data sheet graphs or 80% can be used as a conservative approach. The calculation must be done for the maximum input voltage where the peak switch current is highest.

Equation 5. TLV62095 eq_IL_slvsaw2.gif
Equation 6. TLV62095 eq_IL_2_slvsaw2.gif

where


ƒ = Converter switching frequency (typically 1.4MHz)
L = Inductor value
η = Estimated converter efficiency (use the number from the efficiency curves or 0.80 as a conservative assumption)

Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation current. A margin of 20% should be added to cover for load transients during operation.

8.2.1.2.4 Input and Output Capacitor Selection

For best output and input voltage filtering, low ESR (X5R or X7R) ceramic capacitors are recommended. The input capacitor minimizes input voltage ripple, suppresses input voltage spikes and provides a stable system rail for the device. A 22-μF or larger input capacitor is recommended. The output capacitor value can range from 10 μF up to 150 μF and beyond. Load transient testing and measuring the bode plot are good ways to verify stability with larger capacitor values.

The recommended typical output capacitor value is 2 x 22 μF (nominal) and can vary over a wide range as outline in the output filter selection table. Ceramic capacitor have a DC-Bias effect, which has a strong influence on the final effective capacitance. Choose the right capacitor carefully in combination with considering its package size and voltage rating.

8.2.1.2.5 Setting the Output Voltage

The output voltage is set by an external resistor divider according to the following equations:

Equation 7. TLV62095 EQ2_vout_lvsaw2.gif
Equation 8. TLV62095 EQ3_R2_lvsaw2.gif
Equation 9. TLV62095 EQ4_R1_lvsaw2.gif

When sizing R2, in order to achieve low quiescent current and acceptable noise sensitivity, use a minimum of 5 µA for the feedback current IFB. Larger currents through R2 improve noise sensitivity and output voltage accuracy.

8.2.1.3 Application Performance Curves

TA = 25°C, VIN = 3.6 V, VOUT = 1.8 V, unless otherwise noted.

TLV62095 D001_SLVSBD8_TPS62095.gif
Figure 8. Efficiency, VOUT = 1.8 V
TLV62095 D018_SLVSBD8_TPS62095.gif
Figure 10. Efficiency, VOUT = 2.6 V
TLV62095 D002_SLVSBD8_TPS62095.gif
Figure 12. Load Regulation, VOUT = 1.8 V, VIN = 3.3 V
TLV62095 D008_SLVSBD8_TPS62095.gif
Figure 14. Switching Frequency, VOUT = 1.8 V
TLV62095 D010_SLVSBD8_TPS62095.gif
Figure 16. Output Ripple, VOUT = 1.8 V, IOUT = 3.5 A
TLV62095 D012_SLVSBD8_TPS62095.gif
Figure 18. Startup, Relative to EN, RLOAD = 1.5 Ω
TLV62095 D014_SLVSBD8_TPS62095.gif
Figure 20. Load Transient, VOUT = 1.8 V
TLV62095 D016_SLVSBD8_TPS62095.gif
Figure 22. Short Circuit, HICCUP Protection Exit
TLV62095 D017_SLVSBD8_TPS62095.gif
Figure 9. Efficiency, VOUT = 1.2 V
TLV62095 D019_SLVSBD8_TPS62095.gif
Figure 11. Efficiency, VOUT = 3.3 V
TLV62095 D007_SLVSBD8_TPS62095.gif
Figure 13. Line Regulation, VOUT = 1.8 V, IOUT = 1.0 A
TLV62095 D009_SLVSBD8_TPS62095.gif
Figure 15. Output Ripple, VOUT = 1.8 V, IOUT = 100 mA
TLV62095 D011_SLVSBD8_TPS62095.gif
Figure 17. Startup, Relative to VIN, RLOAD = 1.5 Ω
TLV62095 D013_SLVSBD8_TPS62095.gif
Figure 19. Load Transient, VOUT = 1.8 V
TLV62095 D015_SLVSBD8_TPS62095.gif
Figure 21. Short Circuit, HICCUP Protection Entry