How do I wire my dg413 analog switch?

Thread Starter

engelbrekt

Joined Apr 21, 2021
10
Hello, I want to apologize at first for the ugly schematic, I am a newbie at all of this.
I'm trying to wire up my dg413. I want to switch between a variable voltage from 0-5v and a fixed voltage. I can't get this to work, always shows weird numbers when measuring.

Regards

Schematic_dg413_2021-04-21.png
 

Attachments

sghioto

Joined Dec 31, 2017
2,395
I believe you need to connect the VL pin to ground in order to accomodate input voltages down to zero volts.
If that doesn't work try increasing the supply voltage to 15 volts or connecting a 10K resistor from the common connection of IN3 and IN4 to ground
 
Last edited:

sarahMCML

Joined May 11, 2019
42
Hello, I want to apologize at first for the ugly schematic, I am a newbie at all of this.
I'm trying to wire up my dg413. I want to switch between a variable voltage from 0-5v and a fixed voltage. I can't get this to work, always shows weird numbers when measuring.

Regards

View attachment 236168
The way you have it wired is with a normally closed switch connected to a normally open one. When you flip the control input you just reverse the two, maintaining the status quo, so no signal gets through from the pot!
 

sarahMCML

Joined May 11, 2019
42
First rule is don't run wires through a component.
It makes the schematic hard to read.
I made a mistake reading the schematic in reply #3, my excuse being my old eyesight and the schematic as drawn.
Looking at it again, and reading the datasheet, I think the problem may be that the VL is set for a TTL input level, but V+ at 12V means it expects a CMOS high level, so isn't switching. So connecting V+ to 5V should cure the problem.
 

MrChips

Joined Oct 2, 2009
24,233
And another thing, when drawing circuit schematics, don't use the IC pin layout.
Use a functional symbolic diagram so that it is easier to follow the function of the IC.

Here is what a functional diagram looks like:
1619060165263.png

Make sure to include the IC pin numbers in the drawing.
 

Thread Starter

engelbrekt

Joined Apr 21, 2021
10
I believe you need to connect the VL pin to ground in order to accomodate input voltages down to zero volts.
If that doesn't work try increasing the supply voltage to 15 volts or connecting a 10K resistor from the common connection of IN3 and IN4 to ground
Putting a pulldown resistor to the input for the control logic seems to have solved the problem.
 
Top