LM385 ...

Discussion in 'Electronic Design' started by Fred Bartoli, Jan 5, 2009.

  1. Fred Bartoli

    Fred Bartoli Guest

    Speaking of LM385,

    I've a nice app where its low bias current could shine (the adjust
    version with no internal divider) but the voltage ref is tied on cathode
    on the wrong side (I'd need the ref tied to anode).

    No the TL431 won't work because of the huge 500nA max input bias. The
    LM385 max 35nA is much better and would be almost OK.

    Anyone know of such a beast ?

    Oh, and the footprint has to be ***tiny*** SOT23 would barely do. SC70
    would be better.
    Oh and 125°C temp range with low bias on the range...

    Relax, the voltage accuracy/drift isn't so important...
    But size is : (7mm dia PCB)

    Maybe in my socks?

    --
    Thanks,
    Fred.
     
    Fred Bartoli, Jan 5, 2009
    #1
    1. Advertising

  2. Fred Bartoli

    Fred Bartoli Guest

    mook johnson a écrit :
    > "Fred Bartoli" <" "> wrote in message
    > news:49628126$0$15782$...
    >> Speaking of LM385,
    >>
    >> I've a nice app where its low bias current could shine (the adjust version
    >> with no internal divider) but the voltage ref is tied on cathode on the
    >> wrong side (I'd need the ref tied to anode).
    >>
    >> No the TL431 won't work because of the huge 500nA max input bias. The
    >> LM385 max 35nA is much better and would be almost OK.
    >>
    >> Anyone know of such a beast ?
    >>
    >> Oh, and the footprint has to be ***tiny*** SOT23 would barely do. SC70
    >> would be better.
    >> Oh and 125°C temp range with low bias on the range...
    >>
    >> Relax, the voltage accuracy/drift isn't so important...
    >> But size is : (7mm dia PCB)
    >>
    >> Maybe in my socks?
    >>
    >> --
    >> Thanks,
    >> Fred.

    >
    > what are your using it for. 1.24V reference?
    >
    >


    Opamp and offset reference, almost like the TL431 are used in SMPSs, but
    its for a really high impedance circuit, and with all the tricks
    exhausted I still do need LM385 style the low bias current.
    Given the allowed estate I'd even prefer a JFET/MOS input but it can't
    be, so...


    --
    Thanks,
    Fred.
     
    Fred Bartoli, Jan 6, 2009
    #2
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Joerg

    LM385: Could it be retiring?

    Joerg, Apr 23, 2007, in forum: Electronic Components
    Replies:
    8
    Views:
    420
    Joerg
    Apr 24, 2007
  2. Joerg

    LM385: Could it be retiring?

    Joerg, Apr 23, 2007, in forum: Electronic Design
    Replies:
    12
    Views:
    631
    Joerg
    Apr 24, 2007
  3. krw

    LM385

    krw, Jan 2, 2009, in forum: Electronic Design
    Replies:
    0
    Views:
    326
Loading...

Share This Page