What's your opamp dual supply from single supply jellybean solution?

[ArdWar]

I feel 7660-style charge pumps are in the once great solution but now getting too expensive for what they offer. Today you can pick random cheap buck converter, wire it in inverting mode, and still end up with cheaper BOM and higher current capacity.

Maybe if you already have something that oscillate in your circuit (free MCU pin, another DCDC, etc) you can build your own charge pump for "free".

[Thomas]

LM2766 is a good one: https://www.digikey.com/en/products/detail/texas-instruments/LM2766M6X-NOPB/2514776
More modern (?) and better than the 7660:
2.7 - 5.5V
200mA
2MHz
$1.12 in single quantities

[dusan]

LM2766 is a good one: https://www.digikey.com/en/products/detail/texas-instruments/LM2766M6X-NOPB/2514776
More modern (?) and better than the 7660:
2.7 - 5.5V
200mA
2MHz
$1.12 in single quantities

But that doesn't create negative voltage only doubles input voltage.

[PCB.Wiz]

But that doesn't create negative voltage only doubles input voltage.

Correct.
The cheapest way to get modest +/- OpAmp supplies is to use a x3232 (3v3-5V) or x232 (5V) UART transceiver, lcsc have those from as low as ~10c/500+

[jasonRF]

 If I don’t need to get down to DC (eg when doing audio) then I often don’t bother.  I just use input and output caps, such as in figure 1 or 2 of

https://www.analog.com/en/resources/analog-dialogue/articles/avoiding-op-amp-instability-problems.html

Especially when I just need a buffer so there is no extra cap required for the feedback. 

[Thomas]

Brainfart lol. I probably meant LM2776:
https://www.digikey.com/en/products/detail/texas-instruments/LM2776DBVR/5356685

[Zero999]

I generally avoid it. Most of the time a dual supply isn't necessary. If it's audio, then go with AC coupled, single supply. If it's DC, then level shift and use differential outputs. That will enable you to have positive and negative input/outputs without a bipolar PSU.

Here's an example of a Howland current source I designed to drive a valve with +/-7.5mA, using a +/-10V control signal, yet runs from a single 12V power supply.

[rvalente]

Great share! Tks, I was looking for something similar, need to drive 120mA proportioning valve.

For this 7.5mA, what op-amp did you use?

[Zero999]

Great share! Tks, I was looking for something similar, need to drive 120mA proportioning valve.

For this 7.5mA, what op-amp did you use?

I think it was the OP200 for U1 & U2 and a generic op-amp amp, such as the old '741 fro U3.

The circuit actually has a differential input. If the negative input has a potential divider on it, a positive input voltage can be scaled to a current which goes negative. Here's an example showing a 0V to 5V to +/-120mA circuit.


The current capacity of an op-amp can be increased by adding pass transistors. Here's an example of a similar circuit using ordinary op-amps to get 100mA out.

[rvalente]

Holly molly, you know the jazz when it comes to howland current pumps! Tks mate, ill base my design on yours.