Using the TPS6102x with Ceramic Output Caps

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Using the TPS6102x with Ceramic Output Caps

description

Using the TPS6102x with Ceramic Output Caps. Datasheet Requires ESR above 30 mOhm. Test Results. TPS61020EVM-025 evaluated with a DC load and with a load transient Evaluated with both recommended output capacitors and non-recommend output ceramic capacitors - PowerPoint PPT Presentation

Transcript of Using the TPS6102x with Ceramic Output Caps

Page 1: Using the TPS6102x with Ceramic Output Caps

Using the TPS6102x with Ceramic Output Caps

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Datasheet Requires ESR above 30 mOhm

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Test Results

• TPS61020EVM-025 evaluated with a DC load and with a load transient

• Evaluated with both recommended output capacitors and non-recommend output ceramic capacitors

• Test conditions: 2.5V in, 3.3V out, DC load 500 mA, transient load 200 mA to 500 mA

• Slides 4-7 are the standard EVM circuit with the proper output capacitor, while slides 8-12 use only ceramic

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Output Voltage Ripple (DC Coupled)

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Output Voltage Ripple (AC Coupled)

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Transient Response (DC Coupled)

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Transient Response (AC Coupled)

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EVM Modified by Replacing C3 with 22uF ceramic

Insert 22uF ceramic

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Output Voltage Ripple (DC Coupled)

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Output Voltage Ripple (AC Coupled)

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Transient Response (DC Coupled)

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Transient Response (AC Coupled)

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Conclusion

• TPS6102x is unstable with ceramic output capacitors, which have low ESR– Shows low frequency oscillation/ripple– Performance is normal when output capacitors with

sufficient ESR are used• If ceramic output capacitors are required:– Use the newer, smaller TPS61200– Use ceramic output capacitors with a discrete 30

mOhm resistors in series to give them the needed ESR