R.G's 4053 Circuit

[C.H]

Hello all!

I've been trying to adapt R.G's 4053 bypass system using an arduino, as my aim is to create a digital pedal looper (banks, presets etc.)

When I set the output to high/low, I get a buzz that suggests the output is not strong enough to open/close the switch. I'm familiar with relay driver circuits but I'm set on using the 4053. Is there anything I can incorporate to ensure a steady 6V+ signal from the digital outputs of the chip?

Any and all suggestions would be of great use, thankyou!

[Kevin Mitchell]

I would handle this in one of two ways, the 2nd option doesn't include extra parts.

Add a CD4049 buffer. It'll accept the arduino's high pulse as a logic high and output it's own suppy voltage - which I'm guessing would be 9 volts in your case. It's an inverter so you'll want to use two sections in series or reverse your code (LOW is on, HIGH is off).

The other option is to use the arduino's supply voltage for the 4053. That'll lower it's logic threshold so it'll recognize the arduino's high pulse as a logic high.

-KM

[anotherjim]

To save space, I'd use a single NPN driver (2N3904 is a common choice). A pull-up resistor from the collector output to the "load" power supply, a base input resistor from the MCU. Since the Arduino I/O pins default to inputs on power up, you should also add a pull-down resistor to 0v on the base to stop it floating until the startup code makes the pin an output.
If you do SMD, you can get digital transistors for 5v systems with the base resistors included - only need a collector pull-up.
If you need several higher voltage outputs, its worth using ULN2xxx transistor array chips which have versions for 5v logic in 7 or 8 channels. Again, all outputs need pull-ups. These chips can handle mixed loads -  high voltage logic or relays, motors etc.
...and all of these suggestions are inverters so like Kevin said you need to invert the code to output 0 for an on switch and 1 for an off.