SDLS973 june   2023 LSF0101

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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  LSF0101 AC Performance (Translating Down) Switching Characteristics , VCCB = 3.3 V
    7. 6.7  LSF0101 AC Performance (Translating Down) Switching Characteristics, VCCB = 2.5 V
    8. 6.8  LSF0101 AC Performance (Translating Up) Switching Characteristics, VCCB = 3.3 V
    9. 6.9  LSF0101 AC Performance (Translating Up) Switching Characteristics, VCCB = 2.5 V
    10. 6.10 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Auto Bidirectional Voltage Translation
      2. 8.3.2 Output Enable
    4. 8.4 Device Functional Modes
      1. 8.4.1 Up and Down Translation
        1. 8.4.1.1 Up Translation
        2. 8.4.1.2 Down Translation
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Open-Drain Interface (I2C, PMBus, SMBus, and GPIO)
        1. 9.2.1.1 Design Requirements
          1. 9.2.1.1.1 Enable, Disable, and Reference Voltage Guidelines
          2. 9.2.1.1.2 Bias Circuitry
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Bidirectional Translation
          2. 9.2.1.2.2 Pull-Up Resistor Sizing
          3. 9.2.1.2.3 Single Supply Translation
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Voltage Translation for Vref_B < Vref_A + 0.8 V
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.1.2.2 Pull-Up Resistor Sizing

The pull-up resistor value needs to limit the current through the pass transistor when it is in the ON state to about 15 mA. Doing this causes a voltage drop of 260 mV to 350 mV to have a valid LOW signal on the downstream channel. If the current through the pass transistor is higher than 15 mA, the voltage drop is also higher in the ON state. To set the current through each pass transistor at 15 mA, calculate the pull-up resistor value using the following equation:

Equation 3. Rpu = (Vpu - 0.35 V)0.015 A 

Table 9-3 provides resistor values, reference voltages, and currents at 8 mA, 5 mA, and 3 mA. The resistor value shown in the +10% column (or a larger value) should be used so that the voltage drop across the transistor is 350 mV or less. The external driver must be able to sink the total current from the resistors on both sides of the LSF family device at 0.175 V, although the 15 mA applies only to current flowing through the LSF family device. The device driving the low state at 0.175 V must sink current from one or more of the pull-up resistors and maintain VOL. A decrease in resistance will increase current, and thus result in increased VOL.

Table 9-3 Pull-Up Resistor Values
VPU(1)(2)8 mA5 mA3 mA
NOMINAL (Ω)+10%(3) (Ω)NOMINAL (Ω)+10%(3) (Ω)NOMINAL (Ω)+10%(3) (Ω)
5 V581639930102315501705
3.3 V3694065906499831082
2.5 V269296430473717788
1.8 V181199290319483532
1.5 V144158230253383422
1.2 V106117170187283312
(1) Calculated for VOL = 0.35 V
(2) Assumes output driver VOL = 0.175 V at stated current
(3) +10% to compensate for VDD range and resistor tolerance