SNVA432D March   2010  – January 2022 LM21305

 

  1.   Trademarks
  2. 1 LM21305 Overview
  3. 2 Typical Application Circuit
  4. 3 Evaluation Board Schematic
  5. 4 Evaluation Board Bill of Materials (BOM)
  6. 5 Connection Descriptions
  7. 6 Jumper Settings
  8. 7 Other Design Examples
  9. 8 Typical Performance Characteristics
  10. 9 Component Selection
    1. 9.1 Input Capacitors
    2. 9.2 AVIN Filter
    3. 9.3 Switching Frequency Selection
    4. 9.4 Inductor
    5. 9.5 Output Capacitor
    6. 9.6 Compensation Circuit
  11. 10PCB Layout
  12. 11Revision History

5 Connection Descriptions

Terminal Silkscreen Description
PVIN Connect the power supply between this terminal and the GND terminal beside it. The device is rated between 3 V to 18 V. The absolute maximum voltage rating is 20 V.
GND The GND terminals are meant to provide a close return path to the power and signal terminal beside them. They are all connected together on the board.
SW The SW terminal is connected to the switch node of the power stage. It can be used to monitor the switch node waveform using an oscilloscope.
VOUT The VOUT terminal is connected to the output capacitor on the board and should be connected to the load.
AVIN_EXT The LM21305 evaluation board facilitates using a separate supply voltage to AVIN through JP1 selection and connection to the AVIN_EXT terminal. An AVIN voltage of 5 V will result in optimal efficiency in most cases.
EN This terminal connects to the EN pin of the device. The EN is pulled up to AVIN through a 10-kΩ resistor on the board. It also can be externally controlled through this terminal. If driven externally, a voltage typically greater than 1.2 V will enable the device.
PGOOD This terminal connects to the power-good output of the device. There is a 100-kΩ pullup resistor from this pin to the 2V5 bias rail.