Free Circuit Diagram

This is a circuit of SA58672 Small Class-D Audio Amplifier. This circuit is suitable for mobile device. It  has maximum output power of 3.0 W  for a 4ohm load and 1.7W for 8ohm load with power supply of 5V. If we uses 3.6 V power supply, the maximum output power is 900mW with 8ohm load. [...]

For the best advantage as a low noise high input impedance device, the preamp and tone control uses JFET. If the circuit reaches harmonic distortion levels of less than 0.05% with a S/N ratio of over 85 dB, all device parameters are non-critical. 18 dB of cut and boost is allowed by the tone controls. [...]

Effect on the system’s time-domain response is a common problem when designing lowpass filters. The system may fail to recognize significant changes in time because pushing the cuttoff frequency lower slows the step response. The circuit below is presented to solve the problem:

On this circuit diagram, lower cuttoff frequency is allowed without sacrificing [...]

This is an audio line driver circuit using a TSH22. The advantages of this circuit are low distortion, exhibits a wide bandwidth and an output current sufficient to drive medium impedance loads at a high level modulation. Here is the circuit :

This circuit uses two TSH22 that is used in non inverting mode. The gain [...]

3D enhancement is needed to create a fully 3-dimensional sound for most stereo multimedia products. Usually, simple phase-delay circuits is used to produce a widening effect on the perceived sound field. However, there is transaural acoustic crosstalk effect. The following figure shows transaural acoustic crosstalk effect and schematic diagram of simple phase-delay circuits :

Transaural acoustic [...]

This is a HI-FI tone control circuit with high Z input. This circuit is used to control HI-FI tone. Here is the circuit:

To buffer op-amp operated feedback type tone control circuit, this circuit uses 2N3684 JFET. The 2N3684 JFET is implemented on this circuit because it has low noise characteristics and provides the function of [...]