SLIS183 June   2017 LM193-MIL

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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 Voltage Comparison
  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
        1. 8.2.2.1 Input Voltage Range
        2. 8.2.2.2 Minimum Overdrive Voltage
        3. 8.2.2.3 Output and Drive Current
        4. 8.2.2.4 Response Time
      3. 8.2.3 Application Curves
  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 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 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 device will typically be used to compare 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 this comaprator optimal for level shifting to a higher or lower voltage.

8.2 Typical Application

LM193-MIL symapp_slis183.gif Figure 7. Single-Ended and Differential Comparator Configurations Using the LM2903

8.2.1 Design Requirements

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

Table 1. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
Input Voltage Range 0 V to Vsup-2 V
Supply Voltage 4.5 V to VCC maximum
Logic Supply Voltage 0 V to VCC maximum
Output Current (RPULLUP) 1 µA to 4 mA
Input Overdrive Voltage 100 mV
Reference Voltage 2.5 V
Load Capacitance (CL) 15 pF

8.2.2 Detailed Design Procedure

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

  • Input Voltage Range
  • Minimum Overdrive Voltage
  • Output and Drive Current
  • Response Time

8.2.2.1 Input Voltage Range

When choosing the input voltage range, the input common mode voltage range (VICR) must be taken in to account. If temperature operation is below 25°C the VICR can range from 0 V to VCC– 2.0 V. This limits the input voltage range to as high as VCC– 2.0 V and as low as 0 V. Operation outside of this range can yield incorrect comparisons.

The following is a list of input voltage situation and their outcomes:

  1. When both IN- and IN+ are both within the common-mode range:
    1. If IN- is higher than IN+ and the offset voltage, the output is low and the output transistor is sinking current
    2. If IN- is lower than IN+ and the offset voltage, the output is high impedance and the output transistor is not conducting
  2. When IN- is higher than common-mode and IN+ is within common-mode, the output is low and the output transistor is sinking current
  3. 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
  4. When IN- and IN+ are both higher than common-mode, the output is low and the output transistor is sinking current

8.2.2.2 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) should 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 8 and Figure 9 show positive and negative response times with respect to overdrive voltage.

8.2.2.3 Output and Drive Current

Output current is determined by the load/pull-up resistance and logic/pullup voltage. The output current will produce a output low voltage (VOL) from the comparator. In which VOL is proportional to the output current. Use Typical Characteristics to determine VOL based on the output current.

The output current can also effect the transient response. See Response Time for more information.

8.2.2.4 Response Time

Response time is a function of input over drive. See Application Curves for typical response times. The rise and falls times can be determined by the load capacitance (CL), load/pullup resistance (RPULLUP) and equivalent collector-emitter resistance (RCE).

  • The rise time (τR) is approximately τR ~ RPULLUP × CL
  • The fall time (τF) is approximately τF ~ RCE × CL
    • RCE can be determine by taking the slope of Typical Characteristics in its linear region at the desired temperature, or by dividing the VOL by Iout

8.2.3 Application Curves

The following curves were generated with 5 V on VCC and VLogic, RPULLUP = 5.1 kΩ, and 50 pF scope probe.

LM193-MIL C004_alm2402Q1.png Figure 8. Response Time for Various Overdrives
(Positive Transition)
LM193-MIL C006_alm2402Q1.png Figure 9. Response Time for Various Overdrives
(Negative Transition)