LM8262: The output voltage waveforms of distortion. Inverting buffer and non-inverting buffer.

Ken Sato

Part Number: LM8262
Other Parts Discussed in Thread: TINA-TI, LM8261, OPA2991

Hi,

I am designing an inverting buffer circuit and a non-inverting buffer circuit.
The output voltage waveform was distorted.
How can I eliminate the distortion of the waveform?

It seems that there is enough bandwidth in the data sheet, but isn't it the correct circuit?
(Figure 14. Gain/Phase vs. Frequency, SNOS975G –MAY 2001–REVISED AUGUST 2015)

Input

- Waveform : Sine wave
- Amplitude : 8Vpp
- Offset : 0V
- Frequency : 800kHz

Supply Voltage : +5V / -5V

<TINA-TI 9>

Best regardsBuffer.TSC

over 3 years ago

0 Michael Steffes over 3 years ago

Guru 48085 points

Your output signal is asking for 20V/usec slew rate - the device provides on 12V/usec typ.

For good distortion, you need quite a lot more slew rate in the device than the signal demands.

0 kai klaas69 over 3 years ago

Guru 140200 points

Hi,

this is a typical slew rate issue: The slew rate of input signal is too high for the LM8261:

Kai

0 Tim Claycomb over 3 years ago

TI__Genius 15410 points

Hello,

Take a look at the OPA2991 which is rail to rail input/output device and has a slew rate of 21V/us. This should eliminate the slew induced distortion that Michael and Kai have identified.

I also recommend watching our TI Precision Lab Videos on Slew Rate.

Thank you,

Tim Claycomb

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LM8262: The output voltage waveforms of distortion. Inverting buffer and non-inverting buffer.