03458-66509 standalone operation?

[Villain]

Hi,

if I would want to operate the DC reference board of 3458A standalone, what would i need to consider? (not performance wise, but operational wise)
The board is powered by +18V and -15V I saw in the data sheet, but what would i do with J401 (1) for example? I don't even know what its doing exactly.
I am not very familiar with the architecture of the reference board or 3458A.
And what does J400 (1) do?

Maybe someone more experienced can help me out here.

Thanks in advance.

[Kleinstein]

The A9 board is pretty much the standard LTZ1000 circuit. The supply should not need +18 V for the positive side, 15 V and likely also 12 V should be sufficient. The 18 V are just the voltage present with the 3458.

The -15 V should be reasonable close to get the ground current compensation working. If not needed it should also run without the -15 V supply.

J400/J401 are the connectors. On the DMM / carrier board one would have some type of pin headers. To do the connections.

The output of the normal LTZ1000 circuit is sensitive to overload, as this can lead to the heater going too high. 
So for use as a reference voltage source as an instrument one should add some protection in the form of a buffer amplifier.  Given that one needs a buffer anyway, one could as well include the ref. circuit as well.

[Villain]

I understand that these are the connectors but are pins (1) of J400 and J401 some kind of feedback loop for something or can i leave them unconnected for now and just power on the board without worrying too much?

Thank you for taking the time to respond.

[Kleinstein]

The pins are just for the power supply and the output. There is no other external loop or connection needed. In the simplest case it would be a reasonable stable (e.g. 7815 regulator) +15 V to  the pins for the supply and heater supply and the ground for the supply. The output is than from 7 V and the Ref. Zero pin.  Just be aware not to shorten the output, as this would turn on the heater all the way. Even connecting a larger cap can be too much.