NE58633BS,157 NXP Semiconductors, NE58633BS,157 Datasheet - Page 18

• Manufacturer Part Number: NE58633BS,157
• Description: IC AMP AUDIO .04W STER D 32HVQFN
• Manufacturer: NXP Semiconductors
• Type: Class Dr

Specifications of NE58633BS,157

• Output Type: Headphones, 2-Channel (Stereo)
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Max Output Power X Channels @ Load: 40mW x 2 @ 16 Ohm
• Voltage - Supply: 0.9 V ~ 1.7 V
• Features: Depop, Differential Inputs, Microphone, Mute, Short-Circuit Protection
• Mounting Type: Surface Mount
• Product: Class-D
• Output Power: 40 mW
• Available Set Gain: 100 dB
• Thd Plus Noise: 1 %
• Supply Current: 5 mA
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Audio Load Resistance: 32 Ohms
• Input Offset Voltage: 1 mV
• Input Signal Type: Single
• Minimum Operating Temperature: 0 C
• Output Signal Type: Differential, Single
• Supply Type: Single
• Supply Voltage (max): 1.7 V
• Supply Voltage (min): 0.9 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935283227157; NE58633BS; NE58633BS

NXP Semiconductors
NE58633_3
Product data sheet
10.8.2.1 Conceptual diagram of feedforward application
10.8.2.2 Feedforward demo board schematic
10.8.2 Feedforward circuit
Figure 17
microphone samples the noise outside the acoustic plant of the headphone or earphone.
This method produces a noise-cancelling signal that tries to replicate the noise in the
acoustical plant at the loudspeaker and entrance to the ear. The replication is never exact
because the microphone is located outside the headphones; the noise sampled is not a
perfect replica of the noise inside the ear cup, which is altered by passing through the ear
cup as well as by the internal reflections. In fact, in some cases the anti-noise may
actually introduce noise inside the headphones.
The headphone loudspeaker or transducer is used to send the normal audio signal as well
as the feedforward signal providing noise cancellation. The microphone detects the
external noise and its output is amplified and filtered, and phase is inverted by the low
noise preamplifier and music amplifier in the NE58633.
The evaluation demo board uses a typical filter design and may not yield the optimal noise
cancelling performance for a given headphone mechanical-acoustical plant.
Fig 17. Feedforward conceptual diagram
shows the typical feedforward application diagram in which the noise cancelling
human head
Rev. 03 — 19 January 2010
ear
Noise reduction class-D headphone driver amplifier
acoustic
compartment
or plant
E
transducer
(speaker)
external noise
electronic
compartment
headphone
shell or body
2
H.P. driver
FILTER
AMP
noise detection
microphone
NE58633
002aad927
NE58633
© NXP B.V. 2010. All rights reserved.
18 of 27