Saturday, October 22, 2011

Noise reduction class-D headphone driver amplifier

The NE58633 is a noise reduction stereo Class D Bridge-Tied Load (BTL) helmet driver amplifier. Each channel has a Class D driver's helmet BTL amplifier, a electret microphone preamplifier for low noise, noise reduction circuit and returned to the music amplifier input.

NE58633 is the battery voltage from 0.9 V to 1.7 V, the chip employs on-chip DC-DC boost converter and the internal reference voltage Vref which is filtered and country of origin of noise removal. It is a mute control, and plop, and then click a reduction circuit. The amplifier gain of the microphone and amplifier of the filter is fixed with external resistors. Differential architecture provides better noise immunity.

The NE58633 is able to drive through a 800 mVrms 16 Ω or 32 Ω load and offers Electrostatic discharge (ESD) protection and short circuit. Available in 32-pin HVQFN32 (5 mm x 5 mm x 0.85 mm) package for high density of small and layout is ideal for noise-reduction headsets and audio teaching aids.

Caracteristic of NE58633
- Low current consumption of 4.4 mA
- 0.9 V to 1.7 V battery operating voltage range
- 1 % THD+N at VO = 1 VM driving 16 Ω with a battery voltage of 1.5 V
- 10 % THD+N at 800 mVrms output voltage driving 16 Ω and 32 Ω loads with a battery voltage of 1.5 V
- Output noise voltage with noise reduction circuit typically 31 mVrms for Gv(cl) = 25 dB
- On-chip mute function
- Plop and click reduction circuitry
- Class-D BTL differential output configuration
- Electret microphone noise reduction polarization amplifier with external gain adjustment using resistors
- Music and filter amplifier with external gain adjustment using resistors
- DC-to-DC converter circuitry (3 V output) with 2.5 mA (typical) load current
- Internal voltage reference pinned out for noise decoupling
- Available in HVQFN32 package

Block Diagram

Pin Out

Schematic Aplication

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