SDLS967H may   2016  – july 2023 LSF0108-Q1

PRODMIX  

  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 (Q1)
    5. 6.5 Electrical Characteristics - RKS Package
    6. 6.6 Electrical Characteristics - PW Package
    7. 6.7 Switching Characteristics (Translating Down)
    8. 6.8 Switching Characteristics (Translating Up)
    9. 6.9 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
      3. 8.3.3 Wettable Flanks
    4. 8.4 Device Functional Modes
      1. 8.4.1 Up and Down Translation
  10. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 I2C PMBus, SMBus, 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 LSF0108-Q1 Bandwidth
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Mixed-Mode Voltage Translation
        1. 9.2.2.1 Single Supply Translation
        2. 9.2.2.2 Voltage Translation for Vref_B < Vref_A + 0.8 V
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.1.1.1 Enable, Disable, and Reference Voltage Guidelines

As shown in Figure 9-1, Vref_B is connected through a 200-kΩ resistor to the VPU power supply at 5 V and Vref_A is connected to a 1.8 V power supply. The A1 and A2 channels have a maximum output voltage equal to Vref_A , and the B1 and B2 channels have a maximum output voltage equal to VPU .

The LSF0108-Q1 has an EN input that is used to disable the device by setting EN LOW, which places all I/Os in the high-impedance state. The power consumption is very low because LSF0108-Q1 is a switch-type voltage translator. It is recommended to always enable LSF0108-Q1 for bidirectional application (I2C, SMBus, PMBus, or MDIO).

Table 9-2 Application Operating Condition - RKS Package
PARAMETERMINTYPMAXUNIT
Vref_A(1)reference voltage (A)0.655.5V
Vref_Breference voltage (B)Vref_A + 0.85.5V
VI(EN)input voltage on EN pinVref_A + 0.85.5V
Vpupull-up supply voltage0Vref_BV
Table 9-3 Application Operating Condition - PW Package
PARAMETER MIN TYP MAX UNIT
Vref_A(1) reference voltage (A) 0.9 5.5 V
Vref_B reference voltage (B) Vref_A + 0.8 5.5 V
VI(EN) input voltage on EN pin Vref_A + 0.8 5.5 V
Vpu pull-up supply voltage 0 Vref_B V
(1) Vref_A have to be the lowest voltage level across all of inputs and outputs.
Note: The 200 kΩ, bias resistor is required to allow Vref_B to regulate the EN input.

A filter capacitor on Vref_B is recommended. Also Vref_B and VI(EN) are recommended to be at 1.0 V higher than Vref_A for best signal integrity.