T
Terry Given
- Jan 1, 1970
- 0
What level of GBW production spread should I assume for worst-case
testing? the opamp is a TLV274, GBW 3MHz or so.
Cheers
Terry
testing? the opamp is a TLV274, GBW 3MHz or so.
Cheers
Terry
Terry said:What level of GBW production spread should I assume for worst-case
testing? the opamp is a TLV274, GBW 3MHz or so.
Terry said:What level of GBW production spread should I assume for worst-case
testing? the opamp is a TLV274, GBW 3MHz or so.
Cheers
Terry
What level of GBW production spread should I assume for worst-case
testing? the opamp is a TLV274, GBW 3MHz or so.
Cheers
Terry
John said:I read somewhere recently (LTC appnote on thermocouple acquisition, I
think) that opamp gbw and open-loop gain can have bad tc's, so it's
best to way overkill on gain when precision matters.
John
Terry said:I dont care about Aol, only GBW. Its easy to do the simulations, but I
still kind of need a guesstimate for GBW range. 2-6MHz is perhaps enough?
Pooh said:Terry Given wrote:
Easily I would say. +/- 1MHz would be my guess.
Nice to have that data though. Just been using an Infineon CoolMOS part and
the data sheet shows both typical Ron and another 'worst case' curve for 98%
of all devices. They don't say how bad the other 2% are though !
Graham
What level of GBW production spread should I assume for worst-case
testing? the opamp is a TLV274, GBW 3MHz or so.
Cheers
Terry
Jim said:The compensation corner is sufficiently below the transistor effects
that they can be ignored.
Resistors are typically +/- 20%
Capacitors are typically +/- 15%
GBW is proportional to 1/RC
So you're looking at 0.725x < GBW < 1.47x
BUT, The data sheet will usually specify a minimum, so max GBW would
be ~2x the specification minimum.
(TC's ignored, but typically inconsequential.)
...Jim Thompson
Terry said:Hi Jim,
thanks for that - exactly what I/m looking for. Archived with thanks
Note that GBW is usually determined by: Av=gm.Xc where,
gm is 40Ic, Xc is the capaciter reactance. Gm is not a resister.
However, this current is ultimately set by a resister, somewhere.
Kevin Aylward wrote...
Jim's simplification, GBW proportional to 1/RC, still holds.
Winfield said:Kevin Aylward wrote...
Jim's simplification, GBW proportional to 1/RC, still holds.