CA3 10 volt regulator pt #

OMcComis

1 mW
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Jun 14, 2022
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My CA3 is showing 53volts on the 10 volt output. Need a good part # for the regulator. Can find mostly 7800 series regulators which are only good to 35 volts. #'s on case DN2450 16 7C8W Elongated S (Sigma ?) for manufacturer symbol.
 
OMcComis said:
My CA3 is showing 53volts on the 10 volt output. Need a good part # for the regulator. Can find mostly 7800 series regulators which are only good to 35 volts. #'s on case DN2450 16 7C8W Elongated S (Sigma ?) for manufacturer symbol.

https://www.microchip.com/en-us/product/DN2450
https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005404A.pdf

https://endless-sphere.com/forums/viewtopic.php?f=2&t=19540&start=25

https://www.mouser.com/c/?q=DN2450
https://www.digikey.com/en/products/base-product/microchip-technology/150/DN2450/254056
 
Thanks for the info. Unfortunately there doesn't seem to be one available anywhere. The big suppliers are estimating 2023 for an available date.
 
Can not find OEM 10volt regulator for CA-3. Searching DIGIKEY under "Similar Items" I found this:https://www.onsemi.com/pdf/datasheet/fqd7n10l-d.pdf . Anyone have an opinion as to it's compatibility, main parameters like input volts, amps and output look compatible.
 
This is another p/n that's been used in the CA:
IXTY08N50D2
per the link I previously posted. It is also not presently available, but it's specs are
Transistor Polarity: N-Channel
Number of Channels: 1 Channel
Vds - Drain-Source Breakdown Voltage: 500 V
Id - Continuous Drain Current: 800 mA
Rds On - Drain-Source Resistance: 4.6 Ohms
Vgs - Gate-Source Voltage: - 20 V, + 20 V
Vgs th - Gate-Source Threshold Voltage: 4.5 V
Minimum Operating Temperature: - 55 C
Maximum Operating Temperature: + 150 C

Pd - Power Dissipation: 60 W
Channel Mode: Depletion
Specs on your existing one
Transistor Polarity: N-Channel
Number of Channels: 1 Channel
Vds - Drain-Source Breakdown Voltage: 500 V
Id - Continuous Drain Current: 350 mA
Rds On - Drain-Source Resistance: 10 Ohms
Vgs - Gate-Source Voltage: - 20 V, + 20 V
Vgs th - Gate-Source Threshold Voltage: 3.5 V
Minimum Operating Temperature: - 55 C
Maximum Operating Temperature: + 150 C

Pd - Power Dissipation: 2.5 W
Channel Mode: Depletion


I would presume that of those specs, and the ones of the one already on your CA, the ones that match closely should probably also match closely in the new part you use, and the rest may not matter, other than being "at least as good as" the worst-case version of them. I bolded the things that are the same, and underlined the "worst case" (minimum requirement of the two) of the specs that both have available. If the part you can get has better specs (higher current, higher watts, lower ohms, etc) then all the better. :)

But this is the specs for the part you suggest, and some don't match or aren't good enough, particularly that it says it is an Enhancement mode FET rather than Depletion mode (according to JustinLE's post in that thread, it must be a Depletion mode). I italicized the problematic specs:
Transistor Polarity: N-Channel
Number of Channels: 1 Channel

Vds - Drain-Source Breakdown Voltage: 100 V
Id - Continuous Drain Current: 5.8 A
Rds On - Drain-Source Resistance: 350 mOhms
Vgs - Gate-Source Voltage: - 20 V, + 20 V
Minimum Operating Temperature: - 55 C
Maximum Operating Temperature: + 150 C

Pd - Power Dissipation: 2.5 W
Channel Mode: Enhancement

I am not sure what would be a good choice for replacement; I have at least one (probably two) CA3's here that need this repair myself, but haven't gotten around to looking into it. Too many projects. :/

The post by JustinLE in that thread I linked before does mention how you might get a regular FET to work, though I never tried it.
 
OMcComis said:
My CA3 is showing 53volts on the 10 volt output.
BTW, if you're seeing that high a voltage there, there is a good chance that the other regulation to the 5v/etc on there is destroyed, too, and if it also failed in a way that passed on unregulated voltage instead of blocking it, the MCU will be destroyed, and possibly other external parts powered by the CA's 5v (like your throttle, PAS cadence sensor, etc). If you had a torque sensor on there powered by the 10v, that's probably also destroyed. :(

If you like you can test those by feeding 12v to the output pin of Q1 with or without it in place) without the CA connected to the battery. See if the CA boots first, and if it does, you can use it's diagnostic screens and setup menus to verify external sensor operation. The CA may boot and then shutdown for low voltage error; see that thread for some info on that. If you hook the battery voltage (or a voltage higher than whatever you have the shutdown voltage set to) up to just the battery voltage measuring pin, then it won't shutdown.

schematic of input section from that thread:
CA3%20Regulator%20Schema[1].gif
 
Thanks for the help. I ran across a "part selector" that you can plug these parameters into. Will try that. As for my CA, the high voltage shows on the 10volt out and it did fry my PAS sensor, but other than that the unit works normally. Thinking about removing part and providing that voltage with something else.
 
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