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Equivalent Parts for HD404338B09S IC & KRC106M Transistor

wickline

New Member
I have two suspect components on a board - an HD404338B09S 64 pin integrated circuit and a few KRC106M transistors. Attached are data sheets for these with possible exception that the data sheet for the integrated circuit lists the base family and not the complete number marked on the chip I have.

1) I have located a source for the same base part number for which the last 4 characters differ (HD404338A95S). Can anyone confirm if this is an electrical equivalent to what I have or what the significance of the last 4 characters of the part number are?

2) Can anyone advise an electrical equivalent for the KRC106M switching transistor with built in bias resistors that I have?

Thanks in advance for any assistance you can provide!!
 

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sagor1

Active Member
Hm, your datasheet lists a HD404338S as a MASK ROM type of CPU. That means the program, if any, is hardcoded into the CPU itself. Replacing the CPU without the same code internally will simply not work.
I suspect your CPU is a custom pre-programmed unit.

PS: The 2CS4133 comes up as a cross reference to the KRC106M. So does the NTE 2369
 
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sagor1

Active Member
Correction, my cross reference was 4.7K on both legs, not 4.7k and 47k. There should be others out there that match the bias resistors, I just picked the wrong one?
Check carefully what you are finding, to make sure it has the right resistors. One NTE reference shows 4.7/4.7, the other shows 4.7/47 Not sure which is right...
 

wickline

New Member
Weird - I went to NTEpartsDirect.com to order the part and the data sheet R1 & R2 as 4.7k and 4.7k as you say but then if you scroll down to the bottom of the table on the second page of the data sheet it gives the ratio of R1/R2 as .1 which would suggest a possible error in the stated value of R2 (or an incorrectly stated ratio). I'll call NTE tomorrow to see where the error lies before ordering. I'm hopeful this is the correct replacement.
 

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sagor1

Active Member
Weird - I went to NTEpartsDirect.com to order the part and the data sheet R1 & R2 as 4.7k and 4.7k as you say but then if you scroll down to the bottom of the table on the second page of the data sheet it gives the ratio of R1/R2 as .1 which would suggest a possible error in the stated value of R2 (or an incorrectly stated ratio). I'll call NTE tomorrow to see where the error lies before ordering. I'm hopeful this is the correct replacement.
Agree, there is something funny about their spec sheet. The NTE2367 series shows the same, 4.7/4.7 configuration, with a 1:1 ratio, so one of them has to be wrong....
 

wickline

New Member
Ron - thanks as well. I looked at the DigiKey list but I'm struggling to find a supplier for any that match the TO-92 packaging of my KRC106M.
 

ronsimpson

Well-Known Member
Most Helpful Member
Correction, my cross reference was 4.7K on both legs, not 4.7k and 47k.
From the data sheet I posted in #4.
1551054052039.png
FJN3314, FJNS3214, PDTC143...… not available at digikey but you might find some old stock some where. TO-92
 

sagor1

Active Member
Ronsimpson, you are correct with your datasheet. However, NTE lists a NTE2367 and a NTE2369 both with a 4.7/4.7 resistor network on the first page of the datasheet, yet one datasheet states a 0.1 ratio for input R1/R2 resistance, the other a 1.0 resistance ratio for input. One of those datasheets is wrong, and the one with a 0.1 ratio of R1/R2 is probably a 4.7/47 resistor network.
Until someone can verify why there is a difference in ratios for those two different devices, yet showing the same 4.7k resistor networks at the start of the datasheet, it is hard to say which is a correct substitution. Why would NTE make two similar devices with the same resistor network?

Hopefully wickline can find out why there is a difference in ratios.

The problem with the Digikey selections is that they are all "obsolete", not available. This may be true for other substitutes as well, including the NTE devices...
 

ronsimpson

Well-Known Member
Most Helpful Member
I have seen errors in the data sheet for NTE before.
The NTE2369 has an error. I think it is the 4.7/47k part. (ration = 1 to 10)

These old TO-92 parts are not in production. Who uses through hole parts? Surface mount parts are every where.
 

wickline

New Member
Yeah I contacted NTE about the 2369 data sheet - mentioned the 2367 vs 2369 part. They changed the ratio to 1 but at this point I am not confident if they really checked or just started changing values on the data sheet. Becuase of that I'll probably go with the FJN3314 that is on eBay or if I can find it the PDTC143ZS,126 since it has the higher Power Dissipation rating. I'm trying to repair a board so not really my choice on the packaging - just using what will work on the board I have.
 

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wickline

New Member
Love utsource.net for components. In the end though I purchased FJN3314 transistors off eBay as total cost was less with shipping included. Transistors installed on the board and it is working perfectly now!
 

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