SPM0204LE5-QB Knowles Acoustics, SPM0204LE5-QB Datasheet - Page 27
SPM0204LE5-QB
Manufacturer Part Number
SPM0204LE5-QB
Description
MICROPHONE, -38DB, OMNI
Manufacturer
Knowles Acoustics
Datasheet
1.BF-1861-000.pdf
(28 pages)
Specifications of SPM0204LE5-QB
Transducer Function
Microphone
Device Type
Microphone
Directivity
Omni
Sensitivity
-38
Supply Voltage Min
1.5V
Drain Current Max
0.25mA
Supply Voltage
3.6V
Supply Voltage Max
3.6V
Filter Type
RFI
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
SPM0204LE5-QB
Manufacturer:
SKYPILOT
Quantity:
500
Company:
Part Number:
SPM0204LE5-QB-6
Manufacturer:
MICREL
Quantity:
1 745
Part Number:
SPM0204LE5-QB-6
Manufacturer:
KNOWLES
Quantity:
20 000
Company:
Part Number:
SPM0204LE5-QB-T
Manufacturer:
SYNERGY
Quantity:
5 000
MICROPHONE AND SPEAKER BASICS
SPEAKERS
The speaker converts an electrical signal into sound. A cross section of a typical Knowles speaker is shown in Fig. 3.
The basic components of the speaker are: a coil of wire, a metal U-shaped reed called the armature, a pair of permanent
magnets, a drive rod, and a diaphragm.
The coil and armature act as an electromagnet. An alternating current in the coil causes the polarity of the armature to
switch back and forth from north to south. The free end of the armature bends slightly up and down as it is attracted
alternately to the top and bottom magnets (Fig. 4). The diaphragm, pulled along by the drive rod, pumps air in and out of
the speaker. The mechanical motion of the armature is thus converted into sound.
The sound output of a typical Knowles’ speaker is measured in units of dB SPL (sound pressure level) relative to 20 µPa.
Fig. 3: Cross section of a Knowles EH speaker
DIAPHRAGM
DRIVE ROD
OUTPUT TERMINAL
COIL
MAGNETS
ARMATURE
Fig. 4: The motor of the speaker has a coil, an armature, and a pair of permanent magnets.
www.knowles.com
27
Note: All performance curves are typical