OPA564-Q1: help needed to identify an opamp meeting all criteria

Hi Shubhangi,

It looks like you found the ideal device in your previous post, OPA564-Q1 is likely the best option here. 

Note, since the BW is just 17MHz, you may find that you have some inaccuracies in buffering a faster AC signal due to the device running low on loop gain.

Best,

Jacob

Hi Shubhangi,

Yes OPA561 is a similar device in this family of high BW power amps. This device could be a better fit due to the higher slew rate 

OPA561:

OPA564Q1

You are correct on the device ratings, we say 0 to 125C recommended. This is a device from over 20 years ago, so the expectations for industrial temp grade were different. We picked 0 to 125C but as you can see in the datasheet, we still tested some parameters down to -65C:

To put simply, I have very high confidence that this device will operate below 0C.

We unfortunately do not specify a minimum abs max junction temperature, but you can use the storage temp as a reference for what this number would likely be:

Please let me know if you have any questions.

Best,

Jacob

Hi Shubhangi,

10MHz is pretty fast, and we will now potentially run into issues with a lack of loop gain. Loop gain helps the amplifier create accurate voltages on the output of the amplifier. 

If we were to run at 10MHz, there is a high likelihood that that the -3dB point will be so close that we see slight attenuation of the output signal. In other words, if I want to output 1Vpp at 10MHz, I might actually output .8Vpp.

This is further complicated by the challenge in that some devices will have more or less than 17MHz in BW. This means your attenuation factor will potentially change over temperature and process variation. 

What voltage level accuracy do we need here? 

Is it common to see this system operate at 10MHz?

Thanks,

Jacob

Hi Shubhangi,

shubhangi bagal said:

One more thing, the datasheet does show voltage requirements to V+ PWR and V- PWR pins. Should they be connected to V+ and V- respectively?

Yes, this device has separate supplies for the output stage and the input stage. 

Most customers connect these resources together, but there are some customers who like to modulate the output supply voltage to improve efficiency.

shubhangi bagal said:

While I am trying to find out whether 10MHz is a must condition , can you please let me know whether there is  EVB available for these 2 parts - OPA564-Q1 and OPA561? I need to have a look at schematic. Also we may need to order an EVB first.

Due to the age of this device, we unfortunately do not have an EVM available. This device can be put on a standard 20 pin HTSSOP footprint and air wired if needed. 

Thansk,

Jacob

Hey Shubhangi,

Just responded over direct message. 

Please let me know if you have any questions.

Best,

Jacob