uhm... any? i mean it work in voltage range 3-15/18VDC?

Posted on 2003-08-04 06:13:22 by dion

There is always some Isolating circuitry between the uP and the monitored inputs/outpouts. It just make good engineering design practice. Some would call it a fail-safe practice.

Regards, P1 :cool:
Posted on 2003-08-04 10:25:53 by Pone
IIRC, Motorola's line of controllers did. Specifically, 68HCMxxx.
Posted on 2003-08-04 15:25:46 by drhowarddrfine

I look around real quick for Motorola uP as you described. Could not find it.

Could you take a moment and name a single controller, that fits this situation.

Looks like I need to brush up a bit. I would like to get familiar with the part.

Thanks, P1 :cool:
Posted on 2003-08-04 16:53:54 by Pone
I didn't read the docs in detail but the 68HC11 series are cmos microcontrollers with cmos outputs so I "assume" it can handle cmos inputs. I don't have time to check that out. The supply voltage is +5, however. There are other processors with the HC designation that you can also look at.
Posted on 2003-08-05 10:00:50 by drhowarddrfine
work with +5? no...no... i mean the Vcc too is in cmos range. so, it'll be ease design and implementation.
Posted on 2003-08-05 21:09:27 by dion
I would be surprised if you find what your looking for. Im not any authority in this matter, but common sense says they probably dont make such things, simply cause its hard enough keeping them cool at 5V. Microprocessors are seemingly focused on speed (frequency). Heat generated is a function of this speed and the voltage states that lines are being raised and lowered to. Hence higher voltages = more heat for the same frequency clock.

If you do find something, lemme know. ( I make mistakes all the time ;), however, this is my gut feeling... )

Posted on 2003-08-05 23:50:25 by NaN
NaN, i just think that cmos package much cheaper, so, i dont think that it'll matter in safe or not. but same, we are prone to mistakes :)
Posted on 2003-08-06 00:49:50 by dion
What are you designing?

Why do you think that 4xxx CMOS is cheaper?

If you're implementing a lot of glue logic, have you considered programable logic devices like GALs or CPLDs?
Posted on 2003-08-06 03:06:16 by eet_1024
CMOS = Complementary Metal Oxide Semiconductor

CMOS is a widely used type of semiconductor. CMOS semiconductors use both NMOS (negative polarity) and PMOS (positive polarity) circuits. Since only one of the circuit types is on at any given time, CMOS chips require less power than chips using just one type of transistor. This makes them particularly attractive for use in battery-powered devices, such as portable computers. Personal computers also contain a small amount of battery-powered CMOS memory to hold the date, time, and system setup parameters.

CMOS is a chip manufacturing type/process for TTL ( TTL = Transistor to Transistor Logic ) electronic designs.

CMOS is used for Low power TTL applications, like ones running from a small battery.

If you have a supply voltage of 15-18vdc, use a regulator to drop it down for your Vcc for the ICs you are using.

Regards, P1 :cool:
Posted on 2003-08-06 10:03:53 by Pone
eet_1024: well, i think i cant see that uC equal to PLDs nor 40xx :D

Pone: CMOS is used for lower TTL apps??? afaik that CMOS need somekind of level conversion to interface with TTL world, isnt it?

regulator? yes, if the uC is CMOS, then i dont need to use them. this is what i meant.

i thought CMOS chip is cheaper, is it wrong?? i dont talk about type here (4xx or whatever). and its more forgivable in case your supply going wrong? please correct me...
Posted on 2003-08-07 06:19:23 by dion
cmos is a design method not a manufacturing process. ttl chips use bipolar transistors while cmos uses fet transistors.

You do not need to convert cmos to use it for ttl. Rather, it's the other way around. ttl cannot properly drive cmos because ttl output voltage is too low and it's zero level may not be low enough.
Posted on 2003-08-07 08:50:58 by drhowarddrfine