128x128 OLED carrier board Vsl diode?

Archive SparkFun Site Questions/Comments
1

Q: On the OLED carrier board (LCD-00763) schematic, the Vsl terminal of the connector has a 50-ohm resistor in series with what’s called out on the schematic as a BZT5268 diode. Looking this up, I see this an 82V zener.

In the SSD1339 datasheet, figure 10-6 recommends using a couple of '4148 small signal diodes in a series, forward-biased configuration for Vsl.

My firmware sets the data for the power saving command (B0h) to 0x00 (internal VSL) and the OLED/board works fine. Still, I’m trying to understand the rationale behind using an 82V zener diode in this position.

Thoughts?

2

I feel the schematic is specifying a wrong part number…you typically see BZT52C diodes. Maybe something like a BZT52C6V8?

3

I’m thinking the same as macegr, all the BZT52 Series use the same package so maybe SparkFun were lazy

and didn’t create a new variant device in EAGLE… :roll:

4

Thanks. Your replies are reinforcing my belief that this is just a “typo” and that even a BAT54 or two would be fine here. Hopefully a SF rep will chime in and verify or clarify.

Edit: Just had a look at the surface marking on the diode in question and see “W4”. This looks like a BZT52C3V6 (3.6V zener) which definitely makes more sense.