SNVS052E September   1999  – April 2016 LM809 , LM810

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 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 Benefits of Precision Reset Thresholds
        1. 7.3.1.1 Ensuring a Valid Reset Output Down to VCC = 0 V
        2. 7.3.1.2 Negative-Going VCC Transients
        3. 7.3.1.3 Interfacing to µPs with Bidirectional Reset Pins
    4. 7.4 Device Functional Modes
      1. 7.4.1 VCC Supply Voltage Low
      2. 7.4.2 VCC Supply Voltage High
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

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 LM809 and LM810 are a supervisor circuit for microprocessor and digital systems. With a low supply current of only 15 µA, the LM809 and LM810 are ideal for use in portable equipment.

8.2 Typical Application

LM809 LM810 10105701.gif Figure 10. Microprocessor RESET Circuit

8.2.1 Design Requirements

For this design example, use the parameters listed in Table 2 as the input parameters.

Table 2. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
Input supply voltage range 1 V to 5.5 V
Reset output voltage (high) Input supply
Reset output voltage (low) 0 V

8.2.2 Detailed Design Procedure

For the typical application circuit, all that is required is the LM809 or LM810 IC, but TI recommends an input capacitor to help with input voltage transients. A typical input capacitor value is 0.1 uF and must be rated for the highest expected input voltage.

8.2.3 Application Curve

LM809 LM810 typ_app_reset_delay_snvs052.gif Figure 11. Reset Active Timeout