ProTek Pop-Up-Noise-Killer Controls Power Supply Transition Noise

ProTek Analog, a division of ProTek Devices, introduced the PA4201 Pop-Up-Noise-Killer (“PUNK”). This compact device provides the first low-power solution for controlling power supply transition noise (otherwise known as “POP”) in audio circuits and systems. The PA4201 PUNK chip is intended for diverse applications in the consumer electronics industry, including cell phones, PDAs, portable DVD and MP3 players, notebook audio, set-top boxes, digital video recorders, LCD television, and home theater systems.

ProTek PA4201 Pop-Up-Noise-Killer for Controling Power Supply Transition NoiseAvailable in an 8-pin, low profile, 0.6 mm DFN-8 package, PUNK is the first POP device of its kind on the market. The chip features an extremely low supply current requirement (< 1µA), as well as instant “Power UP” and “Power DOWN” muting. PUNK operates as a passive shunt device and consumes less than 500 nA of supply current, while providing more than 45 dB of mute attenuation at the audio lines. Unlike other POP solutions, engineers using PUNK do not have to worry about PSRR, THD+N, low frequency response, crosstalk, or isolation.

According to ProTek Group Vice President V.P. Pai, the PA4201 meets the need for a small, cost-effective POP device with very low power consumption. “PUNK is the first low-power chip enabling designers to manually mute pop-up noise in audio systems,” said Pai. “Unlike an ‘Always ON’ device, the PUNK remains in passive mode, drawing very little current, until power is ON. The chip then becomes active to ‘kill’ pop-up noise. This function can be adjusted depending upon the output conditions of the audio signal.”

With the PA4201 PUNK chip, an external RC circuit can control startup time, allowing the designer to implement SOFT mute on an audio line during normal operation. The SOFT mute delay can be controlled by an external capacitor (CEXT, < 1µF) from 5 mS to 5 minutes. Other competing devices have fixed delays of 220-300 mS.

In addition, the PA4201 requires few external components for its operation, working from low to medium power supply voltages of 2.7 to 5.5 V. As soon as a change in the power supply is detected, the device ensures audio inputs to amplifiers are switched to a convenient, low-impedance voltage rail—preventing the “POP” heard on most audio systems.

The PA4201 is specified for operation over the -40 to +85 degree C temperature range, and its outputs are equipped with ESD (Human Body Model) protection circuitry.

An evaluation board and sample quantities of the PA4201, as well as a SPICE model and parameters for circuit simulation, are available upon request.

About ProTek Analog
ProTek Analog, based in Tempe, Ariz., provides innovative analog solutions for the 21st century. The company manufactures advanced analog switches and multiplexers that work in conjunction with any host controller, EPROM, FPGA, and even home plug standards. A division of ProTek Devices, ProTek Analog offers a wide range of interface, control, radio frequency (RF), linear, and power management products. For more information, contact: ProTek Analog, 2929 S. Fair Lane, Tempe, Arizona 85282 USA. Tel: (602) 431-8101, Fax: (602) 414-5141, E-mail: