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Electronics => Repair => Topic started by: WuLi on October 25, 2015, 08:55:48 am

Title: Agilent E3640A Obsolete part need some help
Post by: WuLi on October 25, 2015, 08:55:48 am

Hi,
I have an Agilent E3640A PS with a defective CS8122 voltage regulator. This voltage regulator was fabricated by On Semiconductors and it became obsolete. I've been looking around the internet trying to find this part but I've been unsuccessful so far. I don't have experience with finding replacements for obsolete parts. Can anybody give me a hand on finding a replacement for this part? Thanks in advance.
John

Title: Re: Agilent E3640A Obsolete part need some help
Post by: tautech on October 25, 2015, 08:57:55 am

Quote from: WuLi on October 25, 2015, 08:55:48 am

Hi,
I have an Agilent E3640A PS with a defective CS8122 voltage regulator. This voltage regulator was fabricated by On Semiconductors and it became obsolete. I've been looking around the internet trying to find this part but I've been unsuccessful so far. I don't have experience with finding replacements for obsolete parts. Can anybody give me a hand on finding a replacement for this part? Thanks in advance.
John

CS8122 package?
Link to datasheet?

Title: Re: Agilent E3640A Obsolete part need some help
Post by: WuLi on October 25, 2015, 09:00:48 am

Sorry,
I forgot that. It's the CS8122YTVA5 Vertical TO220 Package as listed in the datasheet. I've attached the datasheet.
John

Title: Re: Agilent E3640A Obsolete part need some help
Post by: free_electron on October 25, 2015, 02:30:01 pm

That thing was originally made by cherry semiconductors , later borged by ON SEMI.

Lp2957 could do it but cant do more than 300mA ...

I weeded out possible candidates. You will have to check their pinout.
You can mimic the delayed start by adding an r and c to the enable pin.

http://www.digikey.com/product-search/en?pv16=8696&pv16=8698&pv16=12652&pv16=287&pv16=12742&pv16=8169&pv16=8881&pv16=991&pv16=12745&FV=fff40027%2Cfff80182%2Cc00001&k=Regulator&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25 (http://www.digikey.com/product-search/en?pv16=8696&pv16=8698&pv16=12652&pv16=287&pv16=12742&pv16=8169&pv16=8881&pv16=991&pv16=12745&FV=fff40027%2Cfff80182%2Cc00001&k=Regulator&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25)

Title: Re: Agilent E3640A Obsolete part need some help
Post by: Jay_Diddy_B on October 25, 2015, 02:58:25 pm

Hi,

This may help.

Here is the schematic from the E3633A:

(https://www.eevblog.com/forum/repair/agilent-e3640a-obsolete-part-need-some-help/?action=dlattach;attach=178293;image)

It uses the LM2925T this looks to be pin compatible with the CS8122. Here is a link to the datasheet:

http://www.ti.com.cn/cn/lit/ds/symlink/lm2925.pdf (http://www.ti.com.cn/cn/lit/ds/symlink/lm2925.pdf)

Good Luck,

Jay_Diddy_B

Title: Re: Agilent E3640A Obsolete part need some help
Post by: WuLi on October 25, 2015, 04:01:50 pm

Thank you guys for your input. Someone at the Agilent / hp user groups pointed out the LM2925 device to me. It seems to be compatible with the CS8122. I've ordered this device and will test it in my unit as soon as it comes in. Thanks again.
John
Jay_Diddy_B You've found it to ;-) I'll ley you guys know if it works...