Circuits & Schematics Audio - 4

Charles Wenzel Techlib.com Here's a general-purpose 2 watt audio amplifier with excellent overall performance. It is easily configured to serve as an audio output stage for lower power applications or as a more powerful amplifier for ...

Richard Kurzrok EDN The low-cost composite passive filter in this Design Idea requires no dc power and can enhance the performance of audio equipment and instrumentation by rejecting power-supply hum and spurious pickup from AM, FM, and low-band ...

Royce Higashi and Tony Doy, Maxim Integrated Products EDN Low-profile piezoelectric speakers can provide quality sound for portable electronic devices, but they require voltage swings greater than 8 V p-p across the speaker element. Yet, most ...

Guus Colman EDN In many applications, the frequency-conversion steps comprise a buffer, preferably with some extra voltage gain; a mixer; and some filtering. Instead of including an amplifier in front of the mixer, you can easily integrate the ...

Troy Murphy EDN Thanks to its property of applying an equal amount of delay to all frequencies below its cutoff frequency, the Bessel linear-phase filter sees service in audio applications in which it's necessary to remove out-of-band noise without ...

The circuit in Figure 1 can help if you must transfer dc power and audio over a pair of copper wires. One application for such a circuit is a low-cost door-opening system with speech input. The circuit uses only one IC, the well-known LM317 , a ...

Marko Kannisto, Maxim Integrated Application Note 5147 Part 1. There are thermal issues to consider. With a 12 V supply voltage and a 4 Ω load, the amplifier's efficiency with 20 WRMS output power is approximately 85%. We can calculate how ...

Marko Kannisto, Maxim Integrated Application Note 5147 Pretend that the weather is warm and it is a nice time to be outdoors chatting with friends. You want some background music, but where will it come from? When people want portable music, they ...

A direct-conversion radio receiver required an audio gain of 450 from a pentode vacuum tube. A pentode has a high transconductance that is, the ratio of the change in plate current to the change of the control grid voltage that caused it. To get ...

Petre Petrov EDN The popular 555 timer ( LMC555 , SE555 , NE555 , HA555 ) can be used as a PWM/Class-D amplifier for musical instruments or other applications. It can use a wide supply range of 4.5-16 V and produce 200 mA of drive. The audio is fed ...