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Chips with built-in RFI protection

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magic:
Presumably there is nothing wrong with their new parts. But it's weird :P
One consequence is that you can no longer get a DIP 072 from them.

BTW, TI's could be called TLC072 in accordance with their old naming scheme.

Kleinstein:
There is an TLC072 already  (looks more like an improved version of the TLC272).

The naming of the TL072 H is really confusing.  It looks more like a lower cost version of the OPA2991 / TLV9352.
They really should have given it a different name.

A rail to rail design with the cross over between the stages in the middle of the range is odd. That can cause quite some nasty surprised.

magic:
Yep, I too went to their parametric search and these parts are about the only ones rated for 40V supply that they have.

I'm not really convinced that it's RRI because the discontinuity is less severe than in OPA2991 and there is some sign of trouble starting at 2V above the negative rail. But then I don't know what the mid-supply discontinuity is. Some X-Files stuff :scared:

It could simply be that they replaced the P-ch input stage with N-ch which is the reason for all the input-related differences (noise, offset) if the process was optimized for P-ch. And they sell it as 072 because it addresses the "I want something cheap with input range to Vcc" problem.

Still, :palm:

magic:
JRC also plays the RF immunity game :popcorn:

https://www.njr.com/electronic_device/products/NJM8087.html

T3sl4co1l:

--- Quote from: magic on August 25, 2021, 07:08:42 pm ---It's not even remotely comparable to any classic JFET part and it smells a lot like CMOS.

Output saturation curve - straight line, starting from 0V at 0mA. Not only is it R2R, but a bipolar part would typically have some minimum saturation voltage and less output impedance when saturated.
Input offset vs common mode: discontinuous at mid-supply, like in R2R inputs but at a different threshold.
PSRR vs frequency: that one is weird too, equal on both sides.

--- End quote ---

Suspect the Vos vs. Vcm is an artifact of the measurement.  Wouldn't make any sense for that to happen if it's an RRI structure, how would it know what GND is?  It's certainly NOT an RRI type, as it doesn't include GND, but does include VCC as any other classic JFET input stage.

The output range is suspicious, and at the very least must be common-emitter, but could in fact be BiCMOS.  It's also PTC, i.e. the apparent Rds(on) increases with temperature.

Slew rate appears to be the boosted kind, with a high-slew bypass at high |Vin| and smooth settling otherwise.  Rates are somewhat asymmetrical, again suggesting a monopolar input stage.

Ed: oh also, the input bias current, is very clearly not a junction.  JFET gate leakage increases exponentially with temperature, from <pA at RT to ~nA at max.  The -H shows pretty flat ~pA, ticking up only a little at high temp.  That, plus the input noise being literally worse than a fucking TL431, is pretty damning.

Tim

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