I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

Thanks!

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On 09/12/2014 01:58 PM, Jim Thompson wrote:
I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

Thanks!

...Jim Thompson


I'm a fan of the AD8605. It has fast local feedback wrapped round the
output stage, so that its output impedance doesn't climb nearly as fast
as most RROs.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

On Fri, 12 Sep 2014 14:16:12 -0400, Phil Hobbs
wrote:

On 09/12/2014 01:58 PM, Jim Thompson wrote:
I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

Thanks!

...Jim Thompson


I'm a fan of the AD8605. It has fast local feedback wrapped round the
output stage, so that its output impedance doesn't climb nearly as fast
as most RROs.

Cheers

Phil Hobbs

Thanks, Phil! That's how I design them on-chip... local feedback
cures that transconductance nastiness.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

Thanks!

...Jim Thompson

I use a lot of LM7301s, but they are 32 volt parts and cost more than
lower voltage stuff.

LMV931 is OK.

AD8565 isn't cheap, but it's a remarkable part. 16 volts RRIO, 250 mA
peak out, comes off the rails clean in a microsecond, c-load stable.


--

John Larkin Highland Technology, Inc

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

TLV237x

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

"Jim Thompson" wrote
in message ...
I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

Thanks!

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Fri, 12 Sep 2014 15:51:37 -0500, "Tim Williams"
wrote:

TLV237x

Tim

Thanks for all the tips.

I sent the client (in Taiwan) a solution using the AD8605 that Phil
suggested (and I could find a model for).

I'll provide him also with all the alternates... this is a slow loop
so I think any will do.

Thanks again.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.


--

John Larkin Highland Technology, Inc

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

On 9/13/2014 1:21 PM, John Larkin wrote:
On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.



Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
dual!

http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Cheers

Phil Hobbs



--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

On Sat, 13 Sep 2014 19:43:20 -0400, Phil Hobbs
wrote:

On 9/13/2014 1:21 PM, John Larkin wrote:
On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.



Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
dual!

http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Cheers

Phil Hobbs

But not RRIO.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Sat, 13 Sep 2014 10:21:49 -0700, John Larkin
wrote:

On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.

I'm paying less than that for the quad. Less than half for the single
(though I haven't used any). Yeah, it's a general purpose opamp with
nothing special going for it except its cost. It is R-R I/O, which
command a premium over others. I can get non R-R opamps from NJR for
well under $.10 but they're pretty old-school bipolars. I'm trying to
keep my analog rail under 5V, which kinda dictates R-R.

On 9/13/2014 8:27 PM, Jim Thompson wrote:
On Sat, 13 Sep 2014 19:43:20 -0400, Phil Hobbs
wrote:

On 9/13/2014 1:21 PM, John Larkin wrote:
On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.



Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
dual!

http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Cheers

Phil Hobbs

But not RRIO.

...Jim Thompson


Picky, picky.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

"Phil Hobbs" wrote in message
...
Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
dual!

http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Speaking of, I've been looking for "single supply" (includes ground) or
RRIO chips with higher supply voltage (12V minimum, 16 preferred for
reliability). Catch is: needs more GBW than an LM358.

Closest I've seen is CA3130, but it seems rather obscure (almost
everything CA- is utterly obsolete, though Intersil still seems to be
supporting a few).

There was one or two from TI or LT that meet or exceed (particularly in
offset), but they're no cheaper.

Decomp or current feedback would be fine (it's for gain ~ 50, GBW =
25MHz), but both are like hens' teeth, or have way too much GBW (video
amps, etc.).

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

On 9/13/2014 11:33 PM, Tim Williams wrote:
"Phil Hobbs" wrote in message
...
Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
dual!

http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Speaking of, I've been looking for "single supply" (includes ground) or
RRIO chips with higher supply voltage (12V minimum, 16 preferred for
reliability). Catch is: needs more GBW than an LM358.

Closest I've seen is CA3130, but it seems rather obscure (almost
everything CA- is utterly obsolete, though Intersil still seems to be
supporting a few).

I remember those. The CA3140 was more or less the same part, but with a
bipolar totem-pole output stage.

The CA3100 was magic back in about 1980--it was the only amp we could
find that could handle multiple channel PSK data in a 3-MHz bandwidth
with acceptable intermod.

TI makes a bunch of quite reasonable higher-voltage op amps, e.g. the
OPA188/2188/4188 chopamps.

Cheers

Phil Hobbs



There was one or two from TI or LT that meet or exceed (particularly in
offset), but they're no cheaper.

Decomp or current feedback would be fine (it's for gain ~ 50, GBW =
25MHz), but both are like hens' teeth, or have way too much GBW (video
amps, etc.).

Tim



--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

"Phil Hobbs" wrote in message
...
On 9/13/2014 1:21 PM, John Larkin wrote:
On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.



Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a dual!


http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Cheers
Phil Hobbs


But the LM358 doesn't use any bias, and so there is crossover distortion at
the mid point if used in a linear application such as audio. Maybe that's
not an issue for other applications?

-Bill




--- news://freenews.netfront.net/ - complaints: ---

On 9/14/2014 11:55 PM, Bill Bowden wrote:
"Phil Hobbs" wrote in message
...
On 9/13/2014 1:21 PM, John Larkin wrote:
On Fri, 12 Sep 2014 22:52:21 -0400, wrote:

On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
wrote:

I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
current mirror.

What specs?

What would you guys in the discrete world recommend as being
well-behaved, no peculiarities, etc? (And readily available ;-)

I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.

That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.



Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a dual!


http://octopart-clicks.com/click/vpt...077166e&vpid=1
16013415

Cheers
Phil Hobbs


But the LM358 doesn't use any bias, and so there is crossover distortion at
the mid point if used in a linear application such as audio. Maybe that's
not an issue for other applications?

-Bill

For nine cents in onesies, he expects perfection. An arrant varlet,
forsooth.

LM358s and 324s are occasionally useful, but usually in unipolar
applications, true. A figure of merit for a given design is how crappy
an amplifier you can use and have it still work well.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net