Currently I'm trying to make a circuit for the ESP8266EX Chip and I've stumbled across the "Crystal Oscillator" - section.
It's said that the ESP8266EX supports 40MHz, 26MHz and 24MHz crystal oscillators, with +-10PPM. In the schematic on page 9/30 there are 4 pins on the oscillator. XIN; XOUT; GND; GND. When I try to select an oscillator using the easyEDA software I can never find 2x GND outputs. It's always one ground and one VDD pin.
Basically I think I'm just getting confused by the labeling. What I would've done is, connect GND to GND and VDD to GND.
This is the oscillator I'm talking about in particular. When implementing him to easyEDA the pin no.4 is not GND but rather VDD.
So, what does the VDD stand for? According to my research it stands vor Voltage Drain Drain. VSS stands for Voltage Source Source and is 0V, thus VDD being different from 0V.
But how come there is an oscillator in the datasheet with 2xGND and no VDD, while I can only find them with 1xGND and 1xVDD?
Please correct me on my misunderstanding.