SNOSAW8E May   2008  – September 2015 LM7321 , LM7322

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description continued
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 2.7-V Electrical Characteristics
    6. 7.6 ±5-V Electrical Characteristics
    7. 7.7 ±15-V Electrical Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Output Short Circuit Current and Dissipation Issues
      2. 8.3.2 Estimating the Output Voltage Swing
    4. 8.4 Device Functional Modes
      1. 8.4.1 Driving Capacitive Loads
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Similar High-Output Devices
      2. 9.1.2 Other High Performance SOT-23 Ampliers
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  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 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
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. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

9.1.1 Similar High-Output Devices

The LM7332 is a dual rail-to-rail amplifier with a slightly lower GBW capable of sinking and sourcing 100 mA. It is available in SOIC and VSSOP packages.

The LM4562 is dual op amp with very low noise and 0.7-mV voltage offset.

The LME49870 and LME49860 are single and dual low-noise amplifiers that can work from ±22-V supplies.

9.1.2 Other High Performance SOT-23 Ampliers

The LM7341 is a 4-MHz rail-to-rail input and output part that requires only 0.6 mA to operate, and can drive unlimited capacitive load. It has a voltage gain of 97 dB, a CMRR of 93 dB, and a PSRR of 104 dB.

The LM6211 is a 20-MHz part with CMOS input, which runs on ±12-V or 24-V single supplies. It has rail-to-rail output and low noise.

The LM7121 has a gain bandwidth of 235 MHz.

Detailed information on these parts can be found at www.ti.com.

9.2 Typical Application

Figure 67 shows a typical application where the LM732xx is used as a buffer amplifier for the VCOM signal employed in a TFT LCD flat panel:

LM7321 LM7322 20205758.png Figure 67. VCOM Driver Application Schematic

9.2.1 Design Requirements

For this example application, the supply voltage is +5 V, and noninverting gain is necessary.

9.2.2 Detailed Design Procedure

Figure 68 shows the time domain response of the amplifier when used as a VCOM buffer/driver with VREF at ground. In this application, the op amp loop will try and maintain its output voltage based on the voltage on its noninverting input (VREF) despite the current injected into the TFT simulated load. As long as this load current is within the range tolerable by the LM732xx (45-mA sourcing and 65-mA sinking for ±5-V supplies), the output will settle to its final value within less than 2 μs.

LM7321 LM7322 20205759.png Figure 68. VCOM Driver Performance Scope Photo

9.2.3 Application Curve

LM7321 LM7322 20205768.gif Figure 69. Crosstalk Rejection vs. Frequency