For an AC amplifier with single supply voltage to produce positive and negative output swings that are equal in magnitude, the following circuit configuration is most appropriate:
**Correct Circuit Configuration:**
The non-inverting input terminal should be connected to a circuit that provides a biasing voltage at approximately VCC/2, where the op-amp is biased at its mid-supply point.
**Key Requirements:**
1. **Biasing Network**: The input should be biased at VCC/2 to establish a midpoint operating condition. This allows the output to swing equally positive and negative around this midpoint.
2. **Coupling Capacitors**: AC coupling capacitors should be used at both input and output to block DC and allow only AC signals to be amplified.
3. **Feedback Resistors**: The feedback network (Rf and Rin) must be properly designed to determine the gain while maintaining symmetrical output swings.
4. **Power Supply Bypass**: Bypass capacitors should be placed close to the op-amp power supply pins for stability.
**Circuit Details:**
- Input stage with AC coupling capacitor (Cin)
- Non-inverting input connected through a voltage divider creating VCC/2 bias
- Feedback resistor network (Rf and Rin) for gain setting
- Output coupling capacitor (Cout) to block DC
- Load resistor to ground
**Output Swing Analysis:**
With proper biasing at VCC/2:
- Positive peak: Close to VCC
- Negative peak: Close to Ground (or GND reference)
- Maximum symmetric swing: VCC/2 around the midpoint
**Advantages of this configuration:**
- Equal positive and negative output swings
- Efficient use of single supply voltage
- Reduced distortion due to symmetric operation
- Better noise performance
**Applications:**
- Audio amplifiers with single supply
- Sensor signal conditioning
- Audio signal processing
- Biomedical signal amplification
This configuration ensures that the AC amplifier can utilize the full dynamic range of a single supply voltage while maintaining equal positive and negative output swings, which is crucial for undistorted signal amplification.