Forums

CMOS opamp 18V+, RR in and DIP-14?

Started by Joerg April 25, 2015
Gentlemen,

Got an EMI (susceptibility) situation, existing design from a vendor, no 
major changes possible at this point other than 1:1 component swaps. 
It's a quad DIP-14 in standard pinout. Bipolar right now which is 
EMI-prone so it has to be CMOS.

JFET amps are out because we need the input range down to the negative 
rail and they can't do that. CMOS for 18V and higher is slim pickens. 
There are very few like the AD8659 but only available in SO-package. We 
can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount 
but for production that gets old.

Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard 
pinout at up to 18V single supply? The input only needs to reach the 
negative rail, positive doesn't matter.

-- 
Regards, Joerg

http://www.analogconsultants.com/
On 4/25/2015 2:53 PM, Joerg wrote:
> Gentlemen, > > Got an EMI (susceptibility) situation, existing design from a vendor, no > major changes possible at this point other than 1:1 component swaps. > It's a quad DIP-14 in standard pinout. Bipolar right now which is > EMI-prone so it has to be CMOS. > > JFET amps are out because we need the input range down to the negative > rail and they can't do that. CMOS for 18V and higher is slim pickens. > There are very few like the AD8659 but only available in SO-package. We > can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount > but for production that gets old. > > Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard > pinout at up to 18V single supply? The input only needs to reach the > negative rail, positive doesn't matter. >
LMC6484 with a 3V zener in the supply lead? 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, 25 Apr 2015 11:53:20 -0700, Joerg wrote:

> Gentlemen, > > Got an EMI (susceptibility) situation, existing design from a vendor, no > major changes possible at this point other than 1:1 component swaps. > It's a quad DIP-14 in standard pinout. Bipolar right now which is > EMI-prone so it has to be CMOS. > > JFET amps are out because we need the input range down to the negative > rail and they can't do that. CMOS for 18V and higher is slim pickens. > There are very few like the AD8659 but only available in SO-package. We > can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount > but for production that gets old. > > Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard > pinout at up to 18V single supply? The input only needs to reach the > negative rail, positive doesn't matter.
It's good that you're not picky, Joerg. (And alas no, I haven't got a clue.) -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
On 2015-04-25 12:09 PM, Phil Hobbs wrote:
> On 4/25/2015 2:53 PM, Joerg wrote: >> Gentlemen, >> >> Got an EMI (susceptibility) situation, existing design from a vendor, no >> major changes possible at this point other than 1:1 component swaps. >> It's a quad DIP-14 in standard pinout. Bipolar right now which is >> EMI-prone so it has to be CMOS. >> >> JFET amps are out because we need the input range down to the negative >> rail and they can't do that. CMOS for 18V and higher is slim pickens. >> There are very few like the AD8659 but only available in SO-package. We >> can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount >> but for production that gets old. >> >> Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard >> pinout at up to 18V single supply? The input only needs to reach the >> negative rail, positive doesn't matter. >> > LMC6484 with a 3V zener in the supply lead? >
The zener is unfortunately not possible because that would be a hack where the whole certification goes out the window. Only a part change can be justified at this point. The LMC6484 is abs maxed at 16V and we have a nominal 15V supply with the usual tolerances. That would be a white-knuckle ride. If it was abs max 18V it would be a perfect fit. I thought about changing the supply voltage but that has a whole slew of ramifications. -- Regards, Joerg http://www.analogconsultants.com/
On Sat, 25 Apr 2015 11:53:20 -0700, Joerg <news@analogconsultants.com>
wrote:

>Gentlemen, > >Got an EMI (susceptibility) situation, existing design from a vendor, no >major changes possible at this point other than 1:1 component swaps. >It's a quad DIP-14 in standard pinout. Bipolar right now which is >EMI-prone so it has to be CMOS. > >JFET amps are out because we need the input range down to the negative >rail and they can't do that. CMOS for 18V and higher is slim pickens. >There are very few like the AD8659 but only available in SO-package. We >can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount >but for production that gets old. > >Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard >pinout at up to 18V single supply? The input only needs to reach the >negative rail, positive doesn't matter.
I was recently looking at an announcement for an opamp that is specifically EMI hardened. But I can't remember where. Analog Devices, I think. But DIP14? Try a museum maybe! -- John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On 4/25/2015 3:27 PM, Joerg wrote:
> On 2015-04-25 12:09 PM, Phil Hobbs wrote: >> On 4/25/2015 2:53 PM, Joerg wrote: >>> Gentlemen, >>> >>> Got an EMI (susceptibility) situation, existing design from a vendor, no >>> major changes possible at this point other than 1:1 component swaps. >>> It's a quad DIP-14 in standard pinout. Bipolar right now which is >>> EMI-prone so it has to be CMOS. >>> >>> JFET amps are out because we need the input range down to the negative >>> rail and they can't do that. CMOS for 18V and higher is slim pickens. >>> There are very few like the AD8659 but only available in SO-package. We >>> can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount >>> but for production that gets old. >>> >>> Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard >>> pinout at up to 18V single supply? The input only needs to reach the >>> negative rail, positive doesn't matter. >>> >> LMC6484 with a 3V zener in the supply lead? >> > > The zener is unfortunately not possible because that would be a hack > where the whole certification goes out the window. Only a part change > can be justified at this point. The LMC6484 is abs maxed at 16V and we > have a nominal 15V supply with the usual tolerances. That would be a n > white-knuckle ride. If it was abs max 18V it would be a perfect fit. > > I thought about changing the supply voltage but that has a whole slew of > ramifications. >
So tighten the PS tolerance, e.g. +15V, +0/-5%. 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 4/25/2015 3:27 PM, Joerg wrote:
> On 2015-04-25 12:09 PM, Phil Hobbs wrote: >> On 4/25/2015 2:53 PM, Joerg wrote: >>> Gentlemen, >>> >>> Got an EMI (susceptibility) situation, existing design from a vendor, no >>> major changes possible at this point other than 1:1 component swaps. >>> It's a quad DIP-14 in standard pinout. Bipolar right now which is >>> EMI-prone so it has to be CMOS. >>> >>> JFET amps are out because we need the input range down to the negative >>> rail and they can't do that. CMOS for 18V and higher is slim pickens. >>> There are very few like the AD8659 but only available in SO-package. We >>> can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount >>> but for production that gets old. >>> >>> Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard >>> pinout at up to 18V single supply? The input only needs to reach the >>> negative rail, positive doesn't matter. >>> >> LMC6484 with a 3V zener in the supply lead? >> > > The zener is unfortunately not possible because that would be a hack > where the whole certification goes out the window. Only a part change > can be justified at this point. The LMC6484 is abs maxed at 16V and we > have a nominal 15V supply with the usual tolerances. That would be a > white-knuckle ride. If it was abs max 18V it would be a perfect fit. > > I thought about changing the supply voltage but that has a whole slew of > ramifications. >
So tighten the PS tolerance, e.g. +15V, +0/-5%. 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 25/04/2015 19:53, Joerg wrote:
> Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard > pinout at up to 18V single supply? The input only needs to reach the > negative rail, positive doesn't matter. >
Jelly bean LMC660 would be easy to get but Vddmax is 16V. I found AD8548 cmos with 18V rating but only soic not Dip. piglet
On 2015-04-25 1:13 PM, Phil Hobbs wrote:
> On 4/25/2015 3:27 PM, Joerg wrote: >> On 2015-04-25 12:09 PM, Phil Hobbs wrote: >>> On 4/25/2015 2:53 PM, Joerg wrote: >>>> Gentlemen, >>>> >>>> Got an EMI (susceptibility) situation, existing design from a >>>> vendor, no >>>> major changes possible at this point other than 1:1 component swaps. >>>> It's a quad DIP-14 in standard pinout. Bipolar right now which is >>>> EMI-prone so it has to be CMOS. >>>> >>>> JFET amps are out because we need the input range down to the negative >>>> rail and they can't do that. CMOS for 18V and higher is slim pickens. >>>> There are very few like the AD8659 but only available in SO-package. We >>>> can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount >>>> but for production that gets old. >>>> >>>> Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard >>>> pinout at up to 18V single supply? The input only needs to reach the >>>> negative rail, positive doesn't matter. >>>> >>> LMC6484 with a 3V zener in the supply lead? >>> >> >> The zener is unfortunately not possible because that would be a hack >> where the whole certification goes out the window. Only a part change >> can be justified at this point. The LMC6484 is abs maxed at 16V and we >> have a nominal 15V supply with the usual tolerances. That would be a n >> white-knuckle ride. If it was abs max 18V it would be a perfect fit. >> >> I thought about changing the supply voltage but that has a whole slew of >> ramifications. >> > So tighten the PS tolerance, e.g. +15V, +0/-5%. >
It's not that easy when there is an existing design and the regulator doesn't come in such tight tolerance. It is also an application where I'd like to have a little more margin to abs max than 6%. -- Regards, Joerg http://www.analogconsultants.com/
On 2015-04-25 12:22 PM, Tim Wescott wrote:
> On Sat, 25 Apr 2015 11:53:20 -0700, Joerg wrote: > >> Gentlemen, >> >> Got an EMI (susceptibility) situation, existing design from a vendor, no >> major changes possible at this point other than 1:1 component swaps. >> It's a quad DIP-14 in standard pinout. Bipolar right now which is >> EMI-prone so it has to be CMOS. >> >> JFET amps are out because we need the input range down to the negative >> rail and they can't do that. CMOS for 18V and higher is slim pickens. >> There are very few like the AD8659 but only available in SO-package. We >> can buy SOIC-DIP adapters from Aries or Logical Systems and hand-mount >> but for production that gets old. >> >> Does anyone know a RR CMOS opamp with RR inputs in DIP-14 standard >> pinout at up to 18V single supply? The input only needs to reach the >> negative rail, positive doesn't matter. > > It's good that you're not picky, Joerg. > > (And alas no, I haven't got a clue.) >
The only items I am picky with are usually beer and food. No blue cheese in the food and also no cinammon or other weird stuff in my beer. -- Regards, Joerg http://www.analogconsultants.com/