SLVSBJ0F August   2012  – August 2016 TPS22965

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics—VBIAS = 5 V
    6. 7.6 Electrical Characteristics—VBIAS = 2.5 V
    7. 7.7 Switching Characteristics
    8. 7.8 Typical DC Characteristics
    9. 7.9 Typical Switching Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Adjustable Rise Time
      2. 9.3.2 Quick Output Discharge (QOD) (Optional)
      3. 9.3.3 Low Power Consumption During Off State
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 ON and OFF Control
      2. 10.1.2 Input Capacitor (Optional)
      3. 10.1.3 Output Capacitor (Optional)
      4. 10.1.4 VIN and VBIAS Voltage Range
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Inrush Current
        2. 10.2.2.2 Thermal Considerations
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

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9 Detailed Description

9.1 Overview

The TPS22965x device is a single channel, 6-A load switch in an 8-pin 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.

9.2 Functional Block Diagram

TPS22965 fbd_lvsbj0.gif

9.3 Feature Description

9.3.1 Adjustable Rise Time

A capacitor to GND on the CT pin sets the slew rate. The voltage on the CT pin can be as high as 12 V; therefore, the minimum voltage rating for the CT capacitor must 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. This equation accounts for 10% to 90% measurement on VOUT and does NOT apply for CT = 0 pF. Use Table 1 to determine rise times for when CT = 0 pF.

Equation 1. TPS22965 eq1_lvsbj0.gif

where

  • SR is the slew rate (in µs/V)
  • CT is the the capacitance value on the CT pin (in pF)
  • The units for the constant 34 are µs/V. The units for the constant 0.38 are µs/(V × pF).

Rise time can be calculated by multiplying the input voltage by the slew rate. Table 1 contains rise time values measured on a typical device. Rise times shown in Table 1 are only valid for the power-up sequence where VIN and VBIAS are already in steady state condition before the ON pin is asserted high.

Table 1. Rise Time vs CT Capacitor

CT (pF) TYPICAL VALUES at 25°C with a 25 V X7R 10% CERAMIC CAPACITOR on CT(1)
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
0 180 136 94 84 74 70 60
220 547 378 232 202 173 157 129
470 962 654 386 333 282 252 206
1000 1983 1330 765 647 533 476 382
2200 4013 2693 1537 1310 1077 959 766
4700 8207 5490 3137 2693 2200 1970 1590
10000 17700 11767 6697 5683 4657 4151 3350
(1) Rise time (µs) 10% - 90%, CL = 0.1 µF, CIN = 1 µF, RL = 10 Ω, VBIAS = 5 V

9.3.2 Quick Output Discharge (QOD) (Optional)

The TPS22965 includes a 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.

9.3.3 Low Power Consumption During Off State

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

9.4 Device Functional Modes

The Table 2 lists the VOUT pin states as determined by the ON pin.

Table 2. VOUT Connection

ON TPS22965 TPS22965N
L GND Open
H VIN VIN