ZHCSA62B August   2012  – August 2014 TPS22965

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用范围
  3. 3 说明
  4. 4 简化电路原理图
  5. 5 修订历史记录
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics, VBIAS = 5.0 V
    6. 7.6 Electrical Characteristics, VBIAS = 2.5 V
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
    9. 7.9 Typical Switching Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Adjustable Rise Time
      2. 8.3.2 Quick Output Discharge
      3. 8.3.3 Low Power Consumption During Off State
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 ON/OFF Control
      2. 9.1.2 Input Capacitor (Optional)
      3. 9.1.3 Output Capacitor (Optional)
      4. 9.1.4 VIN and VBIAS Voltage Range
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inrush Current
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12器件和文档支持
    1. 12.1 商标
    2. 12.2 静电放电警告
    3. 12.3 术语表
  13. 13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 Detailed Description

8.1 Overview

The device is a single channel, 6-A load switch in an 8-terminal SON package. To reduce the voltage drop in high current rails, the device implements an ultra-low resistance N-channel MOSFET. The device has a programmable slew rate for applications that require specific rise-time.

The device has very low leakage current during off state. This prevents downstream circuits from pulling high standby current from the supply. Integrated control logic, driver, power supply, and output discharge FET eliminates the need for any external components, which reduces solution size and bill of materials (BOM) count.

8.2 Functional Block Diagram

fbd_lvsbj0.gif

8.3 Feature Description

8.3.1 Adjustable Rise Time

A capacitor to GND on the CT terminal sets the slew rate. The voltage on the CT terminal can be as high as 12 V. Therefore, the minimum voltage rating for the CT cap should be 25 V for optimal performance. An approximate formula for the relationship between CT and slew rate when VBIAS is set to 5 V is shown in Equation 1 below. This equation accounts for 10% to 90% measurement on VOUT and does NOT apply for CT = 0 pF. Use table below to determine rise times for when CT = 0 pF.

Equation 1. eq1_lvsbj0.gif

Where,

SR = slew rate (in µs/V)
CT = the capacitance value on the CT terminal (in pF)
The units for the constant 13.4 are µs/V. The units for the constant 0.39 are µs/(V*pF).

Rise time can be calculated by multiplying the input voltage by the slew rate. The table below contains rise time values measured on a typical device. Rise times shown below are only valid for the power-up sequence where VIN and VBIAS are already in steady state condition before the ON terminal is asserted high.

Table 1. Rise Time vs CT Capacitor

CT (pF) RISE TIME (µs) 10% - 90%, CL = 0.1 µF, CIN = 1 µF, RL = 10 Ω, VBIAS = 5 V
TYPICAL VALUES at 25°C with a 25V X7R 10% CERAMIC CAPACITOR on CT
VIN = 5 V VIN = 3.3 V VIN = 1.8 V VIN = 1.5 V VIN = 1.2 V VIN = 1.05 V VIN = 0.8 V
0 127 93 62 55 51 46 42
220 475 314 188 162 141 125 103
470 939 637 359 304 255 218 188
1000 1869 1229 684 567 476 414 344
2200 4020 2614 1469 1211 1024 876 681
4700 8690 5746 3167 2703 2139 1877 1568
10000 18360 12550 6849 5836 4782 4089 3449

8.3.2 Quick Output Discharge

The TPS22965 includes a Quick Output Discharge (QOD) feature. When the switch is disabled, a discharge resistor is connected between VOUT and GND. This resistor has a typical value of 225-Ω and prevents the output from floating while the switch is disabled.

8.3.3 Low Power Consumption During Off State

The ISD VIN supply current is 0.01-µA typical at 1.8-VIN. Typically, the downstream loads would have a significantly higher off-state leakage current. The load switch allows system standby power consumption to be reduced.

8.4 Device Functional Modes

Table 2. Functional Table

ON VIN to VOUT VOUT to GND
L Off On
H On Off