SLCS007K September   1973  – March 2017 LM111 , LM211 , LM311

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 (8-Pin Packages)
    5. 6.5 Thermal Information (20-Pin Package)
    6. 6.6 Electrical Characteristics
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 Voltage Comparison
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Input Voltage Range
        2. 9.2.2.2 Minimum Overdrive Voltage
        3. 9.2.2.3 Output and Drive Current
        4. 9.2.2.4 Response Time
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
  • P|8
  • PS|8
  • PW|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9 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. Validate and test the design implementation to confirm system functionality.

9.1 Application Information

A typical LMx11 application compares a single signal to a reference or two signals against each other. Many users take advantage of the open-drain output to drive the comparison logic output to a logic voltage level to an MCU or logic device. The wide supply range and high voltage capability makes LMx11 optimal for level shifting to a higher or lower voltage.

9.2 Typical Application

LM111 LM211 LM311 app4_lcs007.gif Figure 13. Zero-Crossing Detector

9.2.1 Design Requirements

For this design example, use the parameters listed in Table 1 as the input parameters.

Table 1. Design Parameters

PARAMETER MIN TYP MAX UNIT
VIN Input voltage range –15 13 V
VCC+ Positive supply voltage 15 V
VCC– Negative supply voltage –15
IOUT Output current 20 mA

9.2.2 Detailed Design Procedure

When using LMx11 in a general comparator application, determine the following:

  • Input voltage range
  • Minimum overdrive voltage
  • Output and drive current
  • Response time

9.2.2.1 Input Voltage Range

When choosing the input voltage range, consider the input common mode voltage range (VICR). Operation outside of this range can yield incorrect comparisons.

The following list describes the outcomes of some input voltage situations.

  • When both IN– and IN+ are both within the common-mode range:
    • If IN– is higher than IN+ and the offset voltage, the output is low and the output transistor is sinking current
    • If IN– is lower than IN+ and the offset voltage, the output is high impedance and the output transistor is not conducting
  • When IN– is higher than common mode and IN+ is within common mode, the output is low and the output transistor is sinking current
  • When IN+ is higher than common mode and IN– is within common mode, the output is high impedance and the output transistor is not conducting
  • When IN– and IN+ are both higher than common mode, the output is undefined

9.2.2.2 Minimum Overdrive Voltage

Overdrive voltage is the differential voltage produced between the positive and negative inputs of the comparator over the offset voltage (VIO). To make an accurate comparison the Overdrive voltage (VOD) must be higher than the input offset voltage (VIO). Overdrive voltage can also determine the response time of the comparator, with the response time decreasing with increasing overdrive. Figure 14 and Figure 15 show positive and negative response times with respect to overdrive voltage.

9.2.2.3 Output and Drive Current

Output current is determined by the pullup resistance and pullup voltage. The output current produces a output low voltage (VOL) from the comparator, in which VOL is proportional to the output current. Use Figure 5 to determine VOL based on the output current.

The output current can also effect the transient response.

9.2.2.4 Response Time

The load capacitance (CL), pullup resistance (RPULLUP), and equivalent collector-emitter resistance (RCE) levels determine the transient response. Equation 1 approximates the positive response time. Equation 2 approximates the negative response time. RCE can be determine by taking the slope of Figure 5 in the linear region at the desired temperature, or by Equation 3.

Equation 1. LM111 LM211 LM311 q_tp_slcs006.gif
Equation 2. LM111 LM211 LM311 q_tn_slcs006.gif
Equation 3. LM111 LM211 LM311 q_rce_slcs006.gif

where

  • VOL is the low-level output voltage
  • IOUT is the output current

9.2.3 Application Curves

LM111 LM211 LM311 tc7_lcs007.gif Figure 14. Output Response for Various Input Overdrives
LM111 LM211 LM311 tc8_lcs007.gif Figure 15. Output Response for Various Input Overdrives

9.3 System Examples

Figure 16 through Figure 33 show various applications for the LM111, LM211, and LM311 comparators.

LM111 LM211 LM311 app1_lcs007.gif Figure 16. 100-kHz Free-Running Multivibrator
LM111 LM211 LM311 app2_lcs007.gif
If offset balancing is not used, the BALANCE and BAL/STRB pins must be unconnected. It is also acceptable to short pins together.
Figure 17. Offset Balancing
LM111 LM211 LM311 app3_lcs007.gif
Do not connect strobe pin directly to ground, because the output is turned off whenever current is pulled from the strobe pin.
Figure 18. Strobing
LM111 LM211 LM311 app5_lcs007.gif Figure 19. TTL Interface With High-Level Logic
LM111 LM211 LM311 app6_lcs007.gif Figure 20. Detector for Magnetic Transducer
LM111 LM211 LM311 app8_lcs007.gif Figure 22. Comparator and Solenoid Driver
LM111 LM211 LM311 app10_lcs007.gif Figure 24. Low-Voltage Adjustable Reference Supply
LM111 LM211 LM311 app7_lcs007.gif Figure 21. 100-kHz Crystal Oscillator
LM111 LM211 LM311 app9_lcs007.gif Figure 23. Strobing Both Input and Output Stages Simultaneously
LM111 LM211 LM311 app11_lcs007.gif Figure 25. Zero-Crossing Detector Driving MOS Logic
LM111 LM211 LM311 app12_lcs007.gif Figure 26. Precision Squarer
LM111 LM211 LM311 app13_lcs007.gif Figure 27. Digital Transmission Isolator
LM111 LM211 LM311 app14_lcs007.gif Figure 28. Positive-Peak Detector
LM111 LM211 LM311 app15_lcs007.gif Figure 29. Negative-Peak Detector
LM111 LM211 LM311 app16_lcs007.gif Figure 30. Precision Photodiode Comparator
LM111 LM211 LM311 app17_lcs007.gif Figure 31. Relay Driver With Strobe
LM111 LM211 LM311 app18_lcs007.gif Figure 32. Switching Power Amplifier
LM111 LM211 LM311 app19_lcs007.gif Figure 33. Switching Power Amplifiers