SBOS321E March   2005  – April 2016 TLV3501 , TLV3502


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information: TLV3501
    5. 6.5 Thermal Information: TLV3502
    6. 6.6 Electrical Characteristics
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Operating Voltage
      2. 7.3.2 Input Overvoltage Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Adding External Hysteresis
    2. 8.2 Typical Application
      1. 8.2.1 Relaxation Oscillator
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      2. 8.2.2 High-Speed Window Comparator
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. TI Precision Designs
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Community Resource
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information


机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)

10 Layout

10.1 Layout Guidelines

For any high-speed comparator or amplifier, proper design and printed-circuit board (PCB) layout are necessary for optimal performance. Excess stray capacitance on the active input, or improper grounding, can limit the maximum performance of high-speed circuitry.

Minimizing resistance from the signal source to the comparator input is necessary to minimize the propagation delay of the complete circuit. The source resistance, along with input and stray capacitance, creates an RC filter that delays voltage transitions at the input, and reduces the amplitude of high-frequency signals. The input capacitance of the TLV350x, along with stray capacitance from an input pin to ground, results in several picofarads of capacitance.

The location and type of capacitors used for power-supply bypassing are critical to high-speed comparators. The suggested 2.2-μF tantalum capacitor does not need to be as close to the device as the 0.1-μF capacitor, and may be shared with other devices. The 2.2-μF capacitor buffers the power-supply line against ripple, and the 0.1-μF capacitor provides a charge for the comparator during high-frequency switching.

In a high-speed circuit, fast rising and falling switching transients create voltage differences across lines that would be at the same potential at DC. To reduce this effect, use a ground plane to reduce difference in voltage potential within the circuit board. A ground plane has the advantage of minimizing the effect of stray capacitances on the circuit board by providing a more desirable path for the current to flow. With a signal trace over a ground plane, at high-frequency the return current (in the ground plane) tends to flow right under the signal trace. Breaks in the ground plane (as simple as through-hole leads and vias) increase the inductance of the plane, making it less effective at higher frequencies. Breaks in the ground plane for necessary vias must be spaced randomly.

10.2 Layout Examples

Figure 22 shows an evaluation layout for the TLV3501 8-pin SOIC package; Figure 23 is for the 5-pin SOT-23 package. Both evaluation layouts are shown with SMA connectors that bring signals on and off the board. RT1 and RT2 are termination resistors for +VIN and −VIN, respectively. C1 and C2 are power-supply bypass capacitors. Place the 0.1-μF capacitor closest to the comparator. The ground plane is not shown, but the pads connecting the resistors and capacitors are shown. Figure 24 shows a schematic of this circuit.

TLV3501 TLV3502 tlv3501d_so-8_samp_layout.gif Figure 22. TLV3501D (SOIC) Sample Layout
TLV3501 TLV3502 tlv3501d_sot23_samp_layout.gif Figure 23. TLV3501DBV (SOT-23) Sample Layout
TLV3501 TLV3502 layout_sch.gif Figure 24. Layout Schematic