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# LT1994 Bandwidth

Hi

My customers are considering LT1994 and received questions about bandwidth.

<conditions>
Input signal: ± 1 V
Gain: × 4

#1   What is the bandwidth at this time?
Considering from GBP (70 MHz) when Vs = 3 V,
Is it about 70 ÷ 4 = 17.5 MHz?

Best Regards,

Yuya

• Hi Yuya,

Given that LT1994 has a GBP of 70 MHz, then at gain of 4 the bandwidth could up to 17.5 MHz at Vs = 3V. May I know the application?

Regards.

• Hi Yuya,

I forgot to mention that at large signal applications, we don't consider the Gain-Bandwidth product since it's for small signal. In this case we will use Slew Rate as the limiting factor.

Given LT1994's SR to 65 V/us, the maximum non-distorted signal frequency you can operate the device is Fmax = SR/(2*pi*A).

Vpp = 8 Vpp

A = 4 V

SR = 65 V/us

Therefore; Fmax = 65 V/us /(2*3.1416*4) = 2.59 MHz.

Regards,

Jino

• Hi, JinoL

The application is an oscilloscope.

The condition you taught me is Vs = 3V.

Since VIN = ± 1 V, I think that my customer use it with Vs = ± 5 V.
Is the band of large amplitude in that case the same as Vs = 3V?

Best Regards,

Yuya

• Hi,Jino

Thank you very much for explaining in detail.

When dealing with signals with large amplitudes, I understood using SR, not GBP.

Best Regards,

Yuya