1496 (Gilbert Cell Multiplier) Spice Model ??

[Jim Thompson]

Anyone have a 1496 (Gilbert Cell Multiplier) Spice Model ??

I could roll my own but I'm unsure if the I/C models I have, of that
vintage, would be correct.

Thanks!

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

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

 

[Mike]

On Mon, 26 Jul 2004 18:24:06 -0700, Jim Thompson wrote:

Anyone have a 1496 (Gilbert Cell Multiplier) Spice Model ??

I could roll my own but I'm unsure if the I/C models I have, of that
vintage, would be correct.

The models might be correct, but would they do you any good? When I started
designing ICs, bipolar devices could be designed one by one, and you
started a few years before I did. The design manual for the first process I
worked in was four pages long, and lists geometry-based equations for those
parameters that weren't considered constant. For example:

Rb = (Rcb/Wbc + (2Rb*Lbe/We))/n + K*Rbp*Le/We

Rcb = 19sqrt(Rb)
Rb = base sheet resistance
Rbp = pinched base sheet resistance
n = 1 for single base stripe, 2 for double base stripe
K = 1/(12*(1+(Le/We)^2))

Wbc, Lbe, We, and Le are transistor dimensions.

In all, I have 10 dimension parameters shown for a simple single-base
stripe transistor - for complex geometries we were expected to make our own
models. Every transistor had its own model.

So, the question is, even if you knew your models were good, how would you
know which models to use?

-- Mike --

 

[Jim Thompson]

On Mon, 26 Jul 2004 23:17:56 -0700, Mike <mike@nospam.com> wrote:

On Mon, 26 Jul 2004 18:24:06 -0700, Jim Thompson wrote:

Anyone have a 1496 (Gilbert Cell Multiplier) Spice Model ??

I could roll my own but I'm unsure if the I/C models I have, of that
vintage, would be correct.

The models might be correct, but would they do you any good? When I started
designing ICs, bipolar devices could be designed one by one, and you
started a few years before I did. The design manual for the first process I
worked in was four pages long, and lists geometry-based equations for those
parameters that weren't considered constant. For example:

Rb = (Rcb/Wbc + (2Rb*Lbe/We))/n + K*Rbp*Le/We

Rcb = 19sqrt(Rb)
Rb = base sheet resistance
Rbp = pinched base sheet resistance
n = 1 for single base stripe, 2 for double base stripe
K = 1/(12*(1+(Le/We)^2))

Wbc, Lbe, We, and Le are transistor dimensions.

In all, I have 10 dimension parameters shown for a simple single-base
stripe transistor - for complex geometries we were expected to make our own
models. Every transistor had its own model.

So, the question is, even if you knew your models were good, how would you
know which models to use?

-- Mike --

Designing your own transistors disappeared from the scene LONG ago.

There are 61 bipolar model parameters... now-a-days supplied by the
foundry for each device size/shape.

Rolling your own custom device size/shape is generally no longer
allowed.

I have some Semtech models for a process dating from the vintage of
the 1496, and would probably suffice, but I was hoping for a
subcircuit specifically done for the circuit.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

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

 

[Winfield Hill]

Jim Thompson wrote...

Anyone have a 1496 (Gilbert Cell Multiplier) Spice Model ??

I could roll my own but I'm unsure if the I/C models I have,
of that vintage, would be correct.

Why don't you just "wire up" the individual fab transistors
you'll actually be using?

Thanks,
- Win

(email: use hill_at_rowland-dot-org for now)