At xDevs in test equipment repairs when I see the Dallas (now Analog Devices) NVRAM modules on the board I replace them with new part right away, without wasting any extra time for testing. It’s also handy to install DIP sockets on the PCB for easier future replacement as well, or modification to use obsoleted FRAM modules that do not have time-bomb lithium coin batteries inside. Friend of mine Alex asked about internal construction DS1230 for his HP 3245A repairs.

So here we are. As a test samples I’ve used some old NVRAMs from past HP3458A and Keithley 2002 repairs. All of the specimens were EDIP potted package.

• DS1243Y-120 from 10 week 2003 (used in Keithley 2002 as MEM2 option)
• DS1230Y-100+ from 32 week 2019 (used in HP/Agilent 3458A and HP3245A as NVRAM memory on CPU board)
• DS1220AB-150+ from 39 week 2017 (used in HP/Agilent 3458A as calibration data memory on CPU board)

I’ve managed to get some internal design images together with regular optical photos for reference. Enjoy high-resolution versions if you click on the image.

Internal design is well visible. DS1243 is quite a bit busier with additional timekeeping RTC chip. DS1230 and DS1220 are pretty much the same with coin cell battery tied up. DS1220 perhaps bit easier to get access to battery pins since it’s closer to the edge of the package near pin 1 locations. Pin 1 in all the chips on the images above is oriented in bottom right corners.

From a side view we can see that DS1230 using two IC, one is power controller and second is actual SRAM chip. DS1220 using since IC package with both functions combined on a same die.

3D angled photo also shows in better clarity where the pins are for the battery. Sadly in DS1230 they are pretty close to the middle of the chip package, close to pin 7 and 22.

Stay tuned for more information in future on xDevs pages. If you are interested and want to discuss details, you are welcome at our own IRC chat server: xdevs.com (port 6010, channel: #xDevs.com) or by reaching out with email.