MC33269ST-5.0T3 Voltage Regulator, where to buy?

Other Hardware Hardware Development
1

Hello,

I'm trying to implement an Arduino MEGA board into my PCB that I'm designing and I've come across a part, MC33269ST-5.0T3. I can't seem to find it anywhere, and it isn't on digikey. The closest I can find is this here, but that is a 3.3 volt regulator: https://www.digikey.com/product-detail/en/on-semiconductor/MC33269ST-3-3T3G/MC33269ST-3-3T3GOSCT-ND/2120818

Inspecting my Mega board that I have sitting on my desk it would appear to physically be the same package, and ON Semiconductor doesn't appear to make a 5V version in that type of casing, but I'm wondering if it is at all possible that it is a documentation error, or an obsolete part?

In any case, does anyone know where I can purchase this part, or an equivalent?

2

When you search for an alternate part you usually search something that have the same specs.
In our case:

  • Voltage Output: 5V
  • Max voltage Input: depends what voltages you plan to power with
  • Same voltage dropout or lower
  • Same current output

Search on digikey with these parameters and you must find something.

Hope this helps.

3

Thanks! :slight_smile:

I did find a replacement part that appears to be equivalent, it is the NCP1117ST50T3G manufactured by ON Semiconductor. The part can be found on digikey here.

There also appears to be a similar part by Texas Instruments, LM1117MPX-5.0/NOPB but the output current is 1 A rather than 800mA, and the original part I was looking to replace (the MC33269ST-5.0) had an output current of 800mA as shown in the datasheet here.

4

Which reference design are you looking at?
The original MEGA has footprints for either the MC33269ST or the MC33269D - the latter is available from digikey.
The Current Mega R3 looks like it has an NCP1117...

Those three-terminal linear regulators are relatively interechangeable. Watch the pinout, though. Some go "Input-GND-Output", and some go "Gnd-Output-Input"

the output current is 1 A rather than 800mA

Most of these regulators are going to end up limited by power dissipation from the regulator rather than max current rating (ie they'll achieve the rated current only under ideal conditions of heat-sinking, cooling, and input voltage.)