LF442CN/NOPB

Do you have a data sheet?

If you overdrive the input, the output should slew at 0.6V/us or faster.  The Gain Bandwidth Product gives you an idea of how fast the output should respond but will be affected by how you use the OpAmp (Gain of 10 means only 60kHz bandwidth, for instance).  I saw numbers from a quick search for the part number.

Hi John,

Thanks for your response.

Datasheet for your reference.

Hi Venkatesh,

the rise and fall times can be estimated from the small signal response:

What would you deduce from these figures?

Kai

The data sheet was for YOUR reference.  If you see the slew rate and the gain bandwidth, you can determine how fast your output can transition.

Venkatesh,

Rise and fall time depend on input signal and feedback component selection. The data sheet parameters that play a part are slew rate and bandwith like John was saying. 

Hi John & Ron,

As per Simulation, LF442 Part Rise time looks better than TL032CP.

Please find attachments for reference.

But as per Datasheet & calculation.

TL032CP:

LF442CN/NOPB:

Tr = 0.35/BW

BW = 1Mhz.

Tr = 0.35/1000000 = 350nS

As per Calculation TL032CP looks better than LF442CN which makes sense as per Datasheet parameter Slew rate, which is better in TL032CP.

2.9V/uS of TL032CP vs 1V/uS of LF442CN/NOPB.

Kindly help me understand better.

Thanks,

Venkatesh

LF442 vs TL032CP.docx

Venkatesh,

The rise and fall time is for a VIpp of 10 mV, not 10V. Where did you get the 10V VIpp value?

Hi Ron,

Thanks for your response.

My Application use case is 0-5V ...

For comparison purpose, i used 10Vp-p. 

I tried simulating with 10mVp-p...same response like 10V.

Just for my better understanding, Rise time & Fall time is for 10mVp-p. Why?  

Regards,

Venkatesh

Venkatesh,

Can you provide a schematic of this op amp section? 

10mV is used as a small signal response time. 

Hi Ron,

My signal input is 0 - 5v to this OpAmp.

i believe it should be considered as large step signal.

Can you help me understand in general for calculating rise time & fall time of 0-5V input range?

Regards,

Venkatesh

Hi Venkatesh,

you might want to read this article:

Kai

Thanks Ron for your support.

LF442 Datasheet response curve is with 10K Ohms & 10pF. whereas TL032 is 10K & 100pF. But i agree with your point since TL032 has better slew rate than LF442CN/NOPB part i would expect its response to be faster.

But the simulations response is opposite of Slew rate? Can you please help me understand that.Am i missing something?

Regards,

Venky

Hi Venkatesh,

this is a TINA-TI simulation:

venkatesh_lf442.TSC

Kai