Generating signal from DAC in range of - to +

[Max++]

ุ่I use "STM32 Value line" for generating sinusoids signal by internal DAC. By default the signal from output DAC, it vary from 0(GND) to 3V.
If I want the signal vary in range of -1.5V to 1.5V instead. How can I do?

 

[doraemon]

Hello!

Use an opamp, a resistor divider and make a virtual ground at 1.5V.
Seen from this virtual ground, you will se the 0 as -1.5V and the 3V as +1.5V.

Dora.

 

[D.A.(Tony)Stewart]

for this you need a negative supply voltage perhaps using a linear charge pump and a unity gain amplifier with a 1.5V precision reference for offset.

 

[T3STY]

A simple voltage divider using two resistors will do the trick.

 

[D.A.(Tony)Stewart]

A simple voltage divider using two resistors will do the trick.

If the sine wave does not require a low impedance source the R/2 may be ok , but powering the STM32 is not a good idea for voltage regulation from this.

 

[T3STY]

Hey Sunny, I agree with you if you're taking into account the impedance. But he's only trying to get a -1.5 to +1.5 sinusoidal output instead of the 0 to 3V output that the DAC of STM32 MCU is generating. The MCU would generate a low impedance output anyway, so the voltage divider wouldn't change anything. That's only a matter of changing the GND point.