SNVA113B April   2006  – February 2022 LM2745 , LM2748

 

  1.   Trademarks
  2. 1Introduction
  3. 2Additional Footprints
  4. 3Typical Application Circuit
  5. 4Performance Characteristics (Output Ripple Voltage and Switch Node Voltage)
  6. 5PCB Layout Diagrams
  7. 6Revision History

2 Additional Footprints

An additional footprint D1 is available for a Schottky diode to be placed in parallel with the low-side MOSFET. This component can improve efficiency, due to the lower forward drop than the low-side MOSFET body diode conducting during the anti-shoot–through period. Select a Schottky diode that maintains a forward drop around 0.4 V to 0.6 V at the maximum load current (consult the I-V curve). In addition, select the reverse breakdown voltage to have sufficient margin above the maximum input voltage.

Footprint C13 is available for a multilayer ceramic capacitor (MLCC) connected flush to the source of the low-side MOSFET and drain of the high-side MOSFET, in order to provide low supply impedance. For example, component C13 is used in combination with aluminum electrolytic input filter capacitors, placed in designators C12 and C14. If MLCCs are used in designators C12 and C14, component C13 is not necessary.