question on 12c509

Y

yplim

Guest
Dear all,

I have some questions pertaining to 12cxx pic.

Please kindly help me out. The datasheet is available in www.microchip.com


1. why are the operational and absolute max. supply voltage different?

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins are GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?

3. If a design using a PIC12C509 called for driving an LED directly from
each of the 6 GPIO pins (i.e. each output pin must supply all the current
for its LED, there are no external amplifiers)
a. what is the maximum current each LED could sink if all the LEDS can be on
at the same time?
b. what is the maximum current each LED could sink if the LED are only to be
on one at a time.
c. Does the PIC12C509 actually supply enough current from each pin to light
a standard visible light LED brightly enough to see?

4. From the 12C509 datasheet, if you wanted to design a battery powered
product that used minimum supply current, used a commercial grade 12C509 and
did not need to run particularly fast, what options do you have for design
the 12C509 part of the circuit?

Thank you.

Please reply asap.
 
Took me about 4 hours but I did my best! Pay me money
if you want better.

Dear Mike,

Thanks for your FOUR hours for hard work.

=)

"Mike Harding" <mike_harding@nixspam.fastmail.fm> wrote in message
news:looto0l4ivjniqjkv9g798j24s3mb1k8ls@4ax.com...
On Sun, 7 Nov 2004 15:08:49 +1100, "yplim"
pic_controller@hotmail.com> wrote:

Please kindly help me out. The datasheet is available in
www.microchip.com

I'll do a bit - but the rest is up to you.

1. why are the operational and absolute max. supply voltage different?

Absolute maximum specifications are exactly that! Go
0.0001% over them and you may well destroy the device.

Operational specs. are what you _should_ operate it at.

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins are
GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?

No idea. Read the data sheet carefully and it may well
tell you. From memory PIC I/O pins can, typically, handle
25mA subject to device max. power dissipation.

3. If a design using a
snip - read the data sheet

4. From the 12C509 datasheet, if you wanted to design a battery powered
product that used minimum supply current, used a commercial grade 12C509
and
did not need to run particularly fast, what options do you have for
design
the 12C509 part of the circuit?

If you want a consultant for some reason - pay the money
and hire one.

Please reply asap.

Took me about 4 hours but I did my best! Pay me money
if you want better.

Mike Harding
Click to expand...
 
Matt2 - Amstereo <amstereo@toptusdotcomdotau> wrote:
can 12c508 and 509's be re written?
Normally no. The program memory is OTP only, unless you get the one with
Click to expand...
the UV erase window that is, in which case yes just shove it under an eprom
eraser. I think the erasable part is 12ce50X tho.

I think the 509 also has some EEPROM for data.

--

Wing Wong.
Webpage: http://wing.ucc.asn.au
 
"yplim" <pic_controller@hotmail.com> wrote in message
news:418d9fd5@news.rivernet.com.au...
Dear all,

I have some questions pertaining to 12cxx pic.

Please kindly help me out. The datasheet is available in www.microchip.com


1. why are the operational and absolute max. supply voltage different?

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins are GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?

3. If a design using a PIC12C509 called for driving an LED directly from
each of the 6 GPIO pins (i.e. each output pin must supply all the current
for its LED, there are no external amplifiers)
a. what is the maximum current each LED could sink if all the LEDS can be
on
at the same time?
b. what is the maximum current each LED could sink if the LED are only to
be
on one at a time.
c. Does the PIC12C509 actually supply enough current from each pin to
light
a standard visible light LED brightly enough to see?

4. From the 12C509 datasheet, if you wanted to design a battery powered
product that used minimum supply current, used a commercial grade 12C509
and
did not need to run particularly fast, what options do you have for design
the 12C509 part of the circuit?

Thank you.

Please reply asap.
Click to expand...
The max supply voltage is the absolute maximum including any ripple or
spikes
on the supply. Above this and the device can do weird things or be
destroyed.

The maximum sink/source current for any GPIO pin is 25mA.

Total combined (sink and source added up for each pin) is 100mA
to keep within power dissipation limits.

(These and the rest of the specs are in section 11.0 of the data sheet, ie
"Maximum Ratings")

So you can drive LED's on all ports happily @ 100mA/6 = 16.66 mA.
Or 25mA max one at a time.

LED's run happily at any current, and 'off the shelf types' would give OK
output @ 10mA.

Battery powered, lower frequency and minimise pin drive currents.
You can also use sleep mode if you don't need the processor to run
continuously.

Richard.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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yplim wrote:
Dear all,

I have some questions pertaining to 12cxx pic.

Please kindly help me out. The datasheet is available in
www.microchip.com

1. why are the operational and absolute max. supply voltage
different?
Click to expand...

Go over the absolute max and you will destroy the device.
The specs quoted are not guaranteed up to the absolute max, only the
operational range.

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins
are GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?
3. If a design using a PIC12C509 called for driving an LED directly
from
each of the 6 GPIO pins (i.e. each output pin must supply all the
current
for its LED, there are no external amplifiers)
a. what is the maximum current each LED could sink if all the LEDS
can be on
at the same time?
b. what is the maximum current each LED could sink if the LED are
only to be
on one at a time.
c. Does the PIC12C509 actually supply enough current from each pin
to light
a standard visible light LED brightly enough to see?
Click to expand...
Yes.
Most LEDs will still be visible at only 1 or 2mA. 5mA is a common
figure to operate an indicator LED at. Just because a LED is speced at
say 20mA does not mean you should be running it at that. 20mA @ 5V is
100mW of power, that's a lot and a total waste or power in probably a
majority of applications.
The PICs will happily do up to 20mA or more per output if you need to.

4. From the 12C509 datasheet, if you wanted to design a battery
powered
product that used minimum supply current, used a commercial grade
12C509 and
did not need to run particularly fast, what options do you have for
design
the 12C509 part of the circuit?
Click to expand...
Use an external RC oscillator or 32.768KHz watch crystal. That does use
up some pins though.
Try the newer FLASH based 8 pin PICs, they are nicer than the 509.
Dave :)
 
On Sun, 7 Nov 2004 15:08:49 +1100, "yplim"
<pic_controller@hotmail.com> wrote:

Please kindly help me out. The datasheet is available in www.microchip.com
Click to expand...
I'll do a bit - but the rest is up to you.

1. why are the operational and absolute max. supply voltage different?
Click to expand...
Absolute maximum specifications are exactly that! Go
0.0001% over them and you may well destroy the device.

Operational specs. are what you _should_ operate it at.

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins are GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?
Click to expand...
No idea. Read the data sheet carefully and it may well
tell you. From memory PIC I/O pins can, typically, handle
25mA subject to device max. power dissipation.

3. If a design using a
snip - read the data sheet
Click to expand...

4. From the 12C509 datasheet, if you wanted to design a battery powered
product that used minimum supply current, used a commercial grade 12C509 and
did not need to run particularly fast, what options do you have for design
the 12C509 part of the circuit?
Click to expand...
If you want a consultant for some reason - pay the money
and hire one.

Please reply asap.
Click to expand...
Took me about 4 hours but I did my best! Pay me money
if you want better.

Mike Harding
 
yeah gpio has 6 i/o
but 1 is devoted straightly for input, so shouldnt it be 100mA/5?

thanks.

please advice asap.


"Richard" <rkabz@ellenbrook.net> wrote in message
news:newscache$zp2u6i$8kj$1@news.e-wire.net.au...
"yplim" <pic_controller@hotmail.com> wrote in message
news:418d9fd5@news.rivernet.com.au...
Dear all,

I have some questions pertaining to 12cxx pic.

Please kindly help me out. The datasheet is available in
www.microchip.com


1. why are the operational and absolute max. supply voltage different?

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins are
GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?

3. If a design using a PIC12C509 called for driving an LED directly
from
each of the 6 GPIO pins (i.e. each output pin must supply all the
current
for its LED, there are no external amplifiers)
a. what is the maximum current each LED could sink if all the LEDS can
be
on
at the same time?
b. what is the maximum current each LED could sink if the LED are only
to
be
on one at a time.
c. Does the PIC12C509 actually supply enough current from each pin to
light
a standard visible light LED brightly enough to see?

4. From the 12C509 datasheet, if you wanted to design a battery powered
product that used minimum supply current, used a commercial grade 12C509
and
did not need to run particularly fast, what options do you have for
design
the 12C509 part of the circuit?

Thank you.

Please reply asap.






The max supply voltage is the absolute maximum including any ripple or
spikes
on the supply. Above this and the device can do weird things or be
destroyed.

The maximum sink/source current for any GPIO pin is 25mA.

Total combined (sink and source added up for each pin) is 100mA
to keep within power dissipation limits.

(These and the rest of the specs are in section 11.0 of the data sheet, ie
"Maximum Ratings")

So you can drive LED's on all ports happily @ 100mA/6 = 16.66 mA.
Or 25mA max one at a time.

LED's run happily at any current, and 'off the shelf types' would give OK
output @ 10mA.

Battery powered, lower frequency and minimise pin drive currents.
You can also use sleep mode if you don't need the processor to run
continuously.

Richard.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.788 / Virus Database: 533 - Release Date: 1/11/2004
Click to expand...
 
"yplim" <pic_controller@hotmail.com> wrote in message
news:418f101f$1@news.rivernet.com.au...
yeah gpio has 6 i/o
but 1 is devoted straightly for input, so shouldnt it be 100mA/5?

thanks.

please advice asap.


"Richard" <rkabz@ellenbrook.net> wrote in message
news:newscache$zp2u6i$8kj$1@news.e-wire.net.au...

"yplim" <pic_controller@hotmail.com> wrote in message
news:418d9fd5@news.rivernet.com.au...
Dear all,

I have some questions pertaining to 12cxx pic.

Please kindly help me out. The datasheet is available in
www.microchip.com


1. why are the operational and absolute max. supply voltage different?

2. for a supply voltage of 5V what are the maximum values for
a. total current output from any one of the GPIO ? (The GPIO pins are
GP0
through GP5)
b. Total current out of all the GPIO pins together?
c. Total current in the PIC12C509 Vdd supply pin?

3. If a design using a PIC12C509 called for driving an LED directly
from
each of the 6 GPIO pins (i.e. each output pin must supply all the
current
for its LED, there are no external amplifiers)
a. what is the maximum current each LED could sink if all the LEDS can
be
on
at the same time?
b. what is the maximum current each LED could sink if the LED are only
to
be
on one at a time.
c. Does the PIC12C509 actually supply enough current from each pin to
light
a standard visible light LED brightly enough to see?

4. From the 12C509 datasheet, if you wanted to design a battery powered
product that used minimum supply current, used a commercial grade
12C509
and
did not need to run particularly fast, what options do you have for
design
the 12C509 part of the circuit?

Thank you.

Please reply asap.






The max supply voltage is the absolute maximum including any ripple or
spikes
on the supply. Above this and the device can do weird things or be
destroyed.

The maximum sink/source current for any GPIO pin is 25mA.

Total combined (sink and source added up for each pin) is 100mA
to keep within power dissipation limits.

(These and the rest of the specs are in section 11.0 of the data sheet,
ie
"Maximum Ratings")

So you can drive LED's on all ports happily @ 100mA/6 = 16.66 mA.
Or 25mA max one at a time.

LED's run happily at any current, and 'off the shelf types' would give OK
output @ 10mA.

Battery powered, lower frequency and minimise pin drive currents.
You can also use sleep mode if you don't need the processor to run
continuously.

Richard.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.788 / Virus Database: 533 - Release Date: 1/11/2004
Click to expand...
You are correct. I did not read the data sheet that thoroughly - I didn't
know this was
an exam. Looks like you can read the data sheet OK. You can do it on your
own now.....

Oh, and LED's work OK up to their maximum current rating (better qualify
that too)......

Richard.


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.788 / Virus Database: 533 - Release Date: 1/11/2004
 
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