The TPS61322 datasheet shows a typical circuit like this:

typical TPS61322 circuit

However, it later shows a "layout example" that differs slightly:

layout example of the tps61322

The second picture shows a resistor and capacitor between SW and VOUT pins. I don't know the purpose of these components nor how to go about determining the values of them. The circuit works fine without them.

Why is there a resistor and capacitor between SW and VOUT?


1 Answer 1


They form a snubber circuit:

A snubber circuit consisting of a resistor R1 and a capacitor C2 is needed if the Schottky diode D1 is soldered. The capacitance of C2 must be larger than triple times of the diode capacitance. The typical value of the resistor R1 is 5 Ω, and the typical value of the capacitor C2 is 120 pF.

TPS61322 datasheet p. 17

  • \$\begingroup\$ Thanks for bringing this to my attention. I don't know how I missed this. \$\endgroup\$ Commented Sep 19, 2023 at 21:47
  • \$\begingroup\$ @SoberTillNoon Happy to help. It's much easier when you know what to look for -- I knew it was a snubber so I just hit Ctrl+F "snub" and found the quoted text. Thanks for accepting the answer! \$\endgroup\$
    – Null
    Commented Sep 19, 2023 at 21:49

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