Help identifying this resistor array looking component (Part 2)

[brandon.arnold]

I am trying to understand (a) where capacitors might be, or (b) any part documentation for a similar part historically to this one, for an RC network on this board (see photo 1). The package is SIP-14 and has manufacturer label RE9511. On the PCB, it has a mask label "RCF" which I believe means "RC Filter."

Photo 2 shows symbols I made in KiCAD for these parts, that should explain my theory of how they are put together, with resistor values. Basically, pin 1 is +5V, pin 14 is GND, and each pair of pins (2-3, 4-5, 6-7, 8-9, 10-11, and 12-13) have a relation to each other that I have simplified in photo 3. The way I came to these conclusions is by measuring the resistance between any two pins. For example, across pins 2-14 would read 6 k-Ohm, across pins 1-2 would read 4.5 k-Ohm, across pins 1-3 would read 4.75 k-Ohm, and across pins 3-14 would read 6.25 k-Ohm.

I measured very small capacitance between any two pins, which made it hard to work out the capacitive part of this circuit. But I believe the purpose of a capacitor in this system is to debounce, because this is an input from push buttons into a bus interface.

Can anyone suggest a theory where a capacitor would go in this system? Would it go across the 250 Ohm resistor, the 1.5 k-Ohm resistor, or the 4.5 k-Ohm resistors? I feel like any would work, but it is annoying that I can't find any part on the internet that is anything like this.

Thank you!

[jwet]

I don't know what capacitance you're seeing but a SIP network like this in circuit might have 5 pF of iust parasitic C.  This is like just a terminator with two R's, any C is a parasitic.

You can measure the C if its higher by removing a part and running a sig gen through to see what it is but I suspect that is just R's.

[brandon.arnold]

I don't know what capacitance you're seeing but a SIP network like this in circuit might have 5 pF of iust parasitic C.  This is like just a terminator with two R's, any C is a parasitic.

You can measure the C if its higher by removing a part and running a sig gen through to see what it is but I suspect that is just R's.

This makes sense! Yes, 5 pF is something like what I could measure with my meter. I don't think I measured any capacitance greater than that. So you are probably right that my description above is the entire circuit, or close to it.