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current capacity of bs2p40 — Parallax Forums

current capacity of bs2p40

ArchiverArchiver Posts: 46,084
edited 2004-02-25 21:41 in General Discussion
For the bs2p40, the manual states that "the total per 8-pin group (P0-
P7, P8-P15, X0-X7, OR X8-X15) should not exceed 100ma (source or
sink) if using an external 5-volt regulator."

Does that mean that each of the 4 8-pin groups can handle 100ma EACH,
meaning the stamp can handle a total of 400ma on all 32 pins?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-02-25 15:44
    At 03:15 PM 2/25/04 +0000, andy_watson5 wrote:
    >For the bs2p40, the manual states that "the total per 8-pin group (P0-
    >P7, P8-P15, X0-X7, OR X8-X15) should not exceed 100ma (source or
    >sink) if using an external 5-volt regulator."
    >
    >Does that mean that each of the 4 8-pin groups can handle 100ma EACH,
    >meaning the stamp can handle a total of 400ma on all 32 pins?
    >
    >No, as stated "per 8 pin group". There is a per pin limit (one pin only) and a
    group limit as well. Both limits MUST be observed. This is true of all Stamps.
    The limits vary from Stamp type to Stamp type.

    Regards,

    Bruce Bates



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  • ArchiverArchiver Posts: 46,084
    edited 2004-02-25 16:06
    Yes, I know that each pin can source of sink 30ma. My question is
    about the total overall capacity of all the pins. I have 24 LEDs
    that I need to light up, each LED sucks 10ma. The way I interpret
    the statement in the manual is that I cannot have more than a 100ma
    draw for each of the 4 groups of 8 pins. So I'd have 80ma draw on P0-
    P7, another 80ma draw on P8-P15, and another 80ma draw on X0-X7.

    I just don't know if I'm interpreting the manual correctly.


    --- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...> wrote:
    > At 03:15 PM 2/25/04 +0000, andy_watson5 wrote:
    > >For the bs2p40, the manual states that "the total per 8-pin group
    (P0-
    > >P7, P8-P15, X0-X7, OR X8-X15) should not exceed 100ma (source or
    > >sink) if using an external 5-volt regulator."
    > >
    > >Does that mean that each of the 4 8-pin groups can handle 100ma
    EACH,
    > >meaning the stamp can handle a total of 400ma on all 32 pins?
    > >
    > >No, as stated "per 8 pin group". There is a per pin limit (one pin
    only) and a group limit as well. Both limits MUST be observed. This
    is true of all Stamps.
    > The limits vary from Stamp type to Stamp type.
    >
    > Regards,
    >
    > Bruce Bates
    >
    >
    >
    > >To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > >from the same email address that you subscribed. Text in the
    Subject and Body of the message will be ignored.
    > >
    > >Yahoo! Groups Links
    > >
    > >
    > >
    > >
  • ArchiverArchiver Posts: 46,084
    edited 2004-02-25 17:16
    Our recommendation is 60 mA MAX for all pins; we've pushed it up to 80
    mA but the chip gets very very hot. And, not an the Stamps best day is
    it ever going to sink or source 240 mA. You can either change to
    low-current (2 mA) LEDS or use buffers to handle the your current
    requirements.

    -- Jon Williams
    -- Applications Engineer, Parallax
    -- Dallas Office


    Original Message
    From: andy_watson5 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_J47KCzH8kalPDn34EfaZ9L73vUDm48tL721vnjWXheBWBpEKhD5ZhiXtpbAl93Mxh4VCcGSVC3CeBTB]andywatson@m...[/url
    Sent: Wednesday, February 25, 2004 10:06 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: current capacity of bs2p40


    Yes, I know that each pin can source of sink 30ma. My question is
    about the total overall capacity of all the pins. I have 24 LEDs
    that I need to light up, each LED sucks 10ma. The way I interpret
    the statement in the manual is that I cannot have more than a 100ma
    draw for each of the 4 groups of 8 pins. So I'd have 80ma draw on P0-
    P7, another 80ma draw on P8-P15, and another 80ma draw on X0-X7.

    I just don't know if I'm interpreting the manual correctly.


    --- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...> wrote:
    > At 03:15 PM 2/25/04 +0000, andy_watson5 wrote:
    > >For the bs2p40, the manual states that "the total per 8-pin group
    (P0-
    > >P7, P8-P15, X0-X7, OR X8-X15) should not exceed 100ma (source or
    > >sink) if using an external 5-volt regulator."
    > >
    > >Does that mean that each of the 4 8-pin groups can handle 100ma
    EACH,
    > >meaning the stamp can handle a total of 400ma on all 32 pins?
    > >
    > >No, as stated "per 8 pin group". There is a per pin limit (one pin
    only) and a group limit as well. Both limits MUST be observed. This
    is true of all Stamps.
    > The limits vary from Stamp type to Stamp type.
    >
    > Regards,
    >
    > Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2004-02-25 17:27
    Thanks for the info. In my final version, I plan to have transistors
    or relays to power the LED's, but I'm working on a quick prototype
    for testing, so I was hoping I could just run the LED's from the
    stamp, but it looks like I'll have to try something else. Thanks.

    --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    wrote:
    > Our recommendation is 60 mA MAX for all pins; we've pushed it up to
    80
    > mA but the chip gets very very hot. And, not an the Stamps best
    day is
    > it ever going to sink or source 240 mA. You can either change to
    > low-current (2 mA) LEDS or use buffers to handle the your current
    > requirements.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: andy_watson5 [noparse][[/noparse]mailto:andywatson@m...]
    > Sent: Wednesday, February 25, 2004 10:06 AM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Re: current capacity of bs2p40
    >
    >
    > Yes, I know that each pin can source of sink 30ma. My question is
    > about the total overall capacity of all the pins. I have 24 LEDs
    > that I need to light up, each LED sucks 10ma. The way I interpret
    > the statement in the manual is that I cannot have more than a 100ma
    > draw for each of the 4 groups of 8 pins. So I'd have 80ma draw on
    P0-
    > P7, another 80ma draw on P8-P15, and another 80ma draw on X0-X7.
    >
    > I just don't know if I'm interpreting the manual correctly.
    >
    >
    > --- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...>
    wrote:
    > > At 03:15 PM 2/25/04 +0000, andy_watson5 wrote:
    > > >For the bs2p40, the manual states that "the total per 8-pin group
    > (P0-
    > > >P7, P8-P15, X0-X7, OR X8-X15) should not exceed 100ma (source or
    > > >sink) if using an external 5-volt regulator."
    > > >
    > > >Does that mean that each of the 4 8-pin groups can handle 100ma
    > EACH,
    > > >meaning the stamp can handle a total of 400ma on all 32 pins?
    > > >
    > > >No, as stated "per 8 pin group". There is a per pin limit (one
    pin
    > only) and a group limit as well. Both limits MUST be observed. This
    > is true of all Stamps.
    > > The limits vary from Stamp type to Stamp type.
    > >
    > > Regards,
    > >
    > > Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2004-02-25 21:41
    If you wanted to be 'clever' about your coding,
    you could 'flash' clumps of LED's then 'flash'
    the next clump. Making sure that each clump
    did not exceed the 60 mA rating.

    --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    wrote:
    > Our recommendation is 60 mA MAX for all pins; we've pushed it up to
    80
    > mA but the chip gets very very hot. And, not an the Stamps best
    day is
    > it ever going to sink or source 240 mA. You can either change to
    > low-current (2 mA) LEDS or use buffers to handle the your current
    > requirements.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: andy_watson5 [noparse][[/noparse]mailto:andywatson@m...]
    > Sent: Wednesday, February 25, 2004 10:06 AM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Re: current capacity of bs2p40
    >
    >
    > Yes, I know that each pin can source of sink 30ma. My question is
    > about the total overall capacity of all the pins. I have 24 LEDs
    > that I need to light up, each LED sucks 10ma. The way I interpret
    > the statement in the manual is that I cannot have more than a 100ma
    > draw for each of the 4 groups of 8 pins. So I'd have 80ma draw on
    P0-
    > P7, another 80ma draw on P8-P15, and another 80ma draw on X0-X7.
    >
    > I just don't know if I'm interpreting the manual correctly.
    >
    >
    > --- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...>
    wrote:
    > > At 03:15 PM 2/25/04 +0000, andy_watson5 wrote:
    > > >For the bs2p40, the manual states that "the total per 8-pin group
    > (P0-
    > > >P7, P8-P15, X0-X7, OR X8-X15) should not exceed 100ma (source or
    > > >sink) if using an external 5-volt regulator."
    > > >
    > > >Does that mean that each of the 4 8-pin groups can handle 100ma
    > EACH,
    > > >meaning the stamp can handle a total of 400ma on all 32 pins?
    > > >
    > > >No, as stated "per 8 pin group". There is a per pin limit (one
    pin
    > only) and a group limit as well. Both limits MUST be observed. This
    > is true of all Stamps.
    > > The limits vary from Stamp type to Stamp type.
    > >
    > > Regards,
    > >
    > > Bruce Bates
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