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Power Supply Design
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Poorly Calculated:
I am in need of some assistance for a proper power supply for my project. I am using a Linear Technology LT6207 quad-op amp IC. I will be using the YPbPr to RGB "Typical Application" example provided in its datasheet, found here:  https://www.analog.com/media/en/technical-documentation/data-sheets/620567fc.pdf.

The example circuit shown has a +5V and -5V supply. At first, I thought I would try out two 100kOhm resistors in series to divide some V. Then I'd set a reference ground to be between the two resistors, giving me +V/2 and -V/2. Then I'd add some smoothing capacitors and a 7805 and 7905 regulator to each output respectively. But here is where another problem comes up, the only usable voltages I can find (in the tube TV this is going into) are 120V AC, 165V DC, 12V DC, and 5V DC. Using my voltage division method won't work with the 12V or 5V because the dropout voltage of the regulators I want to use are too high to work with +6V and -6V. Also, the 165V DC is too high and will definitely destroy my regulators. And I don't want to mess with 120V AC if I don't have to.

So I am kind of stuck between a rock and a high voltage place here. Do I just buy an off-the-shelf solution? Or do I use a DC-DC converter? Any and all comments are greatly appreciated.
Zero999:
Schematic?

The problem with using resistors to divide the voltage is the output impedance is equal to the values of both resistors in parallel, which will be 50k in this case. It won't be an issue if the potential divider is being used to bias an op-amp's input, but it won't work for an appreciable load.
spec:

--- Quote from: Poorly Calculated on November 04, 2018, 06:57:30 pm ---...And I don't want to mess with 120V AC if I don't have to.

--- End quote ---
Although you do not wish to mess with 120V AC mains, considering the other options that you mention, that is exactly what I would advice. But you would not have to do much messing with 120V.

I would recommend getting two 5V off-line 120V isolated switching power supplies, which are available quite cheaply from a number of sources, including ebay.

You then  wire the 5V DC outputs to give you two nice, +&- 5V supply lines for your high frequency amplifiers.

This makes for a modular approach which is fairly independent of the circuitry of the mother unit.

I don't know how much experience you have with high frequency work, but just in case be advised that layout decoupling, screening are critical to make high frequency circuits even work half decently. :)

And ground loops and cross coupling are major problems. But, by using isolated independent supplies it is easier to minimize these problems.

If I am telling an old hand at HF techniques the obvious- my apologies. ::)

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