Power SAD with 9 volts

[armdnrdy]

Hi all,

As a few of you know, I'm working on two universal BBD testers. One for the low voltage MN32XX series and one for the MN30XX series. Due to the common use of a positive clock signal, my aim is to combine a good portion of the MN32XX series BBDs and the SAD1024 into the same design. The user friendly design and the analog switching logic demand the use of one clock for all of the different BBDs under test.

The SAD data sheet states minimum supply and clock at 10 volts, but goes on to state that it can be operated at clock voltages down to 5 volts with reduced input bias and signal amplitude. The MN32XX series states maximum supply voltage at 10 volts.

I'm incorporating a MN3102 clock driver to provide the two phase, 50% duty clock signal since it's small, easy to adjust for frequency, and provides the VGG for the MNs.

Looking at the specs, I don't have much wiggle room in the maximum and minimum voltages between the SAD and the MN. If the tester were powered by a wall wart, the voltage could easily run beyond the MNs upper limit.

I've found a couple of references to the SAD being powered by 9 volts which include The Phlanger, (on Mark Hammer's Ampage site) and the 9 volt Electric Mistress. Does anyone have any experience with the SAD at 9 volts?

I have sections of the high voltage tester bread boarded with the CP terminals of the clock measuring about half of the supply. At 9 volts the clock signal to the SAD would be somewhere under 5 volts. Please be advised that I am not concerned with achieving the ultimate performance of the BBDs.

My only other option is to power the test unit with a higher voltage and regulate it down to 10 volts to assure that the voltage stays within the upper limit of the MNs.

Any thoughts?

[oldschoolanalog]

SAD1024 works fine in the 9V EM. No issues at all 

[armdnrdy]

Thanks Dave,

That's what I was hoping to hear!