SBOS309E August 2004 – December 2024 OPA2830
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
Figure 8-5 shows the general form of Figure 8-4 as a dc-coupled noninverting amplifier that level-shifts the input up to accommodate the desired output voltage range. Given the desired signal gain (G), and the amount VOUT must be shifted up (ΔVOUT) when VIN is at the center of the range, the following equations give the resistor values that produce the desired performance. Assume that R4 is between 200Ω and 1.5kΩ.
where:
Ensure that VIN and VOUT stay within the specified input and output voltage ranges.
The circuit of Figure 8-4 is a good example of this type of application. The circuit designed to take VIN between 0V and 0.5V and produce VOUT between 1V and 2V when using a 3V supply. This means G = 2.00, and ΔVOUT = 1.50V – G × 0.25V = 1.00V. Plugging these values into the previous equations (with R4 = 750Ω) gives: NG = 2.33, R1 = 375Ω, R2 = 2.25kΩ, and R3 = 563Ω. The resistors were changed to the nearest standard values for the circuit of Figure 8-4.