MOTM

Hello,

i am searching for a supplier for the 1K 1% 3300 ppm tempco as used in the MOTM-440 & 485.

Can somebody show me the way?

Thank you,

Peter

My 2 beads: Ask Mr Shreiber (Paul) - or Bridechamber.  If you need help with some of the caps, etc, I can take a look at the BOM, etc later this PM and suggest part numbers - they keep shifting.  Let me know.  Will



--- In motm@yahoogroups.com, "peter_ivens" <peter.i@...> wrote:

>
> Hello,
> 
> i am searching for a supplier for the 1K 1% 3300 ppm tempco as used in the MOTM-440 & 485.
> 
> Can somebody show me the way?
> 
> Thank you,
> 
> Peter
>

Yes but they don't mention a temp. coeff. nor do they refere to MOTM under the item so i think it is another coeff.
(Miquel, sorry for the three replies my mistake)

Peter

--- In motm@yahoogroups.com, "Miguel Mendoza" <miguel@...> wrote:

>
> Bridechamber has them: http://www.bridechamber.com/bridechamber.com/Hard_2_Find_ICs.html
> 
> 
> From: peter_ivens 
> Sent: Sunday, May 02, 2010 11:48 PM
> To: motm@yahoogroups.com 
> Subject: [motm] Tempco 1K 3300 ppm
> 
> 
>   
> Hello,
> 
> i am searching for a supplier for the 1K 1% 3300 ppm tempco as used in the MOTM-440 & 485.
> 
> Can somebody show me the way?
> 
> Thank you,
> 
> Peter
>

On 2010-05-02 21:48 -0000, peter_ivens wrote:

> i am searching for a supplier for the 1K 1% 3300 ppm tempco as
> used in the MOTM-440 & 485.
> 
> Can somebody show me the way?

http://www.teaser.fr/~amajorel/sourcing/#tempcos

Anything with "+3300" or "+3500" in the PPM/K column should do.

-- 
Andr\ufffd Majorel http://www.teaser.fr/~amajorel/

Hey André,

i am familiar with your website. A tempco with a temp. coeff. of 3500 , 1K 1%, is not so difficult to find. Most moduls of MOTM use a tempco of 3500 ppm (like the MOTM-300) but in the BOM for the 440 & 485 there is specified 1K 1% 3300 ppm. 
Elby design delivers a second resitor to lower the temp. coeff. but then you can take also a tempco with a tolerance of 5% from Tyco. 
So that is the reason why I ask around for 1K 1% 3300 ppm tempco's.
If it doesn't matter that much I shall use one of 3500 ppm

Peter

--- In motm@yahoogroups.com, Andre Majorel <aym-htnys@...> wrote:

>
> On 2010-05-02 21:48 -0000, peter_ivens wrote:
> 
> > i am searching for a supplier for the 1K 1% 3300 ppm tempco as
> > used in the MOTM-440 & 485.
> > 
> > Can somebody show me the way?
> 
> http://www.teaser.fr/~amajorel/sourcing/#tempcos
> 
> Anything with "+3300" or "+3500" in the PPM/K column should do.
> 
> -- 
> André Majorel http://www.teaser.fr/~amajorel/
>

On 2010-05-03 12:12 -0000, peter_ivens wrote:

> A tempco with a temp. coeff. of 3500 , 1K 1%, is not so
> difficult to find. Most moduls of MOTM use a tempco of 3500 ppm
> (like the MOTM-300) but in the BOM for the 440 & 485 there is
> specified 1K 1% 3300 ppm. 

I don't think it matters much. The tempco of the circuit is
an approximation anyway, because there are other sources of error
than the transistor pair. And so is the tempco of the actual
resistor because it varies with temperature (and possibly from
device to device).

If anything, it's preferable to have a resistor with too high a
tempco because you can always reduce it by wiring an ordinary
metal film resistor in parallel (metal film resistors have tempcos
like 50 or 100 PPM/K).

Check Ian Fritz's "dial-a-tempco" page for a really refined
treatment.

> Elby design delivers a second resitor to lower the temp. coeff.
> but then you can take also a tempco with a tolerance of 5% from
> Tyco. 

Tycos are cheap but aren't they 3000 PPM/K ? The Akaneohm sound
like a much better deal. Or the Panasonic SMT if you're prepared
to some kludgery.

-- 
Andr\ufffd Majorel http://www.teaser.fr/~amajorel/

I found a datasheet on the Tyco website which refers to two types with a temp coeff. of 3000 and 3300 ppm.

André, en tout cas merci pour l' info ...

--- In motm@yahoogroups.com, Andre Majorel <aym-htnys@...> wrote:

>
> On 2010-05-03 12:12 -0000, peter_ivens wrote:
> 
> > A tempco with a temp. coeff. of 3500 , 1K 1%, is not so
> > difficult to find. Most moduls of MOTM use a tempco of 3500 ppm
> > (like the MOTM-300) but in the BOM for the 440 & 485 there is
> > specified 1K 1% 3300 ppm. 
> 
> I don't think it matters much. The tempco of the circuit is
> an approximation anyway, because there are other sources of error
> than the transistor pair. And so is the tempco of the actual
> resistor because it varies with temperature (and possibly from
> device to device).
> 
> If anything, it's preferable to have a resistor with too high a
> tempco because you can always reduce it by wiring an ordinary
> metal film resistor in parallel (metal film resistors have tempcos
> like 50 or 100 PPM/K).
> 
> Check Ian Fritz's "dial-a-tempco" page for a really refined
> treatment.
> 
> > Elby design delivers a second resitor to lower the temp. coeff.
> > but then you can take also a tempco with a tolerance of 5% from
> > Tyco. 
> 
> Tycos are cheap but aren't they 3000 PPM/K ? The Akaneohm sound
> like a much better deal. Or the Panasonic SMT if you're prepared
> to some kludgery.
> 
> -- 
> André Majorel http://www.teaser.fr/~amajorel/
>