1. General description
The NE58633 is a stereo, noise reduction, class-D, Bridge-Tied Load (BTL) headphone
driver amplifier. Each channel comprises a class-D BTL headphone driver amplifier, an
electret microphone low noise preamplifier, feedback noise reduction circuit and a music
amplifier input.
The NE58633 operates with a battery voltage of 0.9 V to 1.7 V. The chip employs an
on-chip DC-to-DC boost converter and internal V
ref
voltage reference which is filtered and
output to ground for noise decoupling. It features mute control and plop and click
reduction circuitry. The gain of the microphone amplifier and filter amplifier is set using
external resistors. Differential architecture provides increased immunity to noise.
The NE58633 is capable of driving 800 mV
rms
across a 16 Ω or 32 Ω load and provides
ElectroStatic Discharge (ESD) and short-circuit protection.
It is available in the 32-pin HVQFN32 (5 mm × 5mm× 0.85 mm) package suitable for
high density small-scale layouts and is an ideal choice for noise reduction headphones
and educational audio aids.
2. Features
Low current consumption of 4.4 mA
0.9 V to 1.7 V battery operating voltage range
1% THD+N at V
O
=1V
M
driving 16 Ω with a battery voltage of 1.5 V
10 % THD+N at 800 mV
rms
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 mV
rms
for G
v(cl)
=25dB
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
NE58633
Noise reduction class-D headphone driver amplifier
Rev. 03 — 19 January 2010 Product data sheet
