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Convert 0..5v PWM to 6,5..11,5v
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Zero999:

--- Quote from: SiliconWizard on December 27, 2018, 06:45:44 pm ---Something like the following (example with a 10kHz PWM signal). The two LP stages get you a decent filtering. The plus is you keep your whole PWM dynamic range. Corollary is it will output ~6.5V even when the PWM signal is not running, which won't be the case with solutions which are just scaling without shifting.

--- End quote ---
Good, except use an op-amp with a rail-to-rail output, such as the NJM2741, OPA342 etc.
Benta:
The OPA342 will not operate at 12 V. You'll need replacement smoke...

The circuit also has a DC gain of over 1. Don't know if that's desired.

SiliconWizard:

--- Quote from: Zero999 on December 27, 2018, 07:30:17 pm ---
--- Quote from: SiliconWizard on December 27, 2018, 06:45:44 pm ---Something like the following (example with a 10kHz PWM signal). The two LP stages get you a decent filtering. The plus is you keep your whole PWM dynamic range. Corollary is it will output ~6.5V even when the PWM signal is not running, which won't be the case with solutions which are just scaling without shifting.

--- End quote ---
Good, except use an op-amp with a rail-to-rail output, such as the NJM2741, OPA342 etc.

--- End quote ---

The OPA342 is a 5.5V max device AFAIK, so probably not this one. ;)
The NJM2741 would be a nice candidate but it doesn't seem available from the usual suppliers (Mouser, Digikey...)

But that's right. A RR opamp. I picked this one as a cheap solution thinking it was RR, but memory didn't serve well and the simulation didn't show any issue going up to 11.5V, but the output is unloaded... (the spice model may suck too).

Given the very modest BW requirements, the op can select pretty much any cheap RR opamp that can operate at 12V.
A reasonably cheap, low-power and widely available candidate would be the TLV170 for instance.
SiliconWizard:

--- Quote from: Benta on December 27, 2018, 07:44:42 pm ---The circuit also has a DC gain of over 1. Don't know if that's desired.

--- End quote ---

Yes, it has a gain of 2. Because the summing network (R4, R5) actually divides the sum by 2. :)
Benta:

--- Quote from: SiliconWizard on December 27, 2018, 08:06:02 pm ---
--- Quote from: Benta on December 27, 2018, 07:44:42 pm ---The circuit also has a DC gain of over 1. Don't know if that's desired.

--- End quote ---

Yes, it has a gain of 2. Because the summing network (R4, R5) actually divides the sum by 2. :)

--- End quote ---

No it doesn't. Do the math.
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