BL-21785-000 Knowles Acoustics, BL-21785-000 Datasheet - Page 14

• Manufacturer Part Number: BL-21785-000
• Description: MIC ELEMENT PIEZO INSTRUMENT
• Manufacturer: Knowles Acoustics
• Series: BLr
• Type: Piezo Condenserr

Specifications of BL-21785-000

• Sensitivity: -69dB ±3dB
• Voltage - Rated: 1.3V
• Current: 160µA
• Size / Dimension: Rectangular - 7.87mm L x 5.54mm W x 2.24mm H
• Impedance: 4K Ohm
• Frequency: 20Hz ~ 10kHz
• Termination: Solder Pads
• Direction: Omnidirectional
• Port Location: Side
• Directional Properties: Omnidirectional
• Operating Voltage: 3 V
• Dimensions: 7.87 mm L x 5.54 mm W x 2.24 mm D
• Depth: 2.24 mm
• Length: 7.87 mm
• Width: 5.54 mm
• Transducer Function: Microphone
• Device Type: Microphone
• Directivity: Omni
• External Diameter: 1.41mm
• Output Impedance: 4000ohm
• Drain Current Max: 160µA
• Outer Diameter: 1.41mm
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Filter Type: -
• S/n Ratio: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 423-1003; BL-1785; BL-21785; BL1785

14
Note: All performance curves are typical
SPECIALTY TRANSDUCERS – Accelerometers & Dampers
BU SERIES
BU Series Accelerometers are frequently used as contact microphones for radio
communications in high noise environments such as firefighting or combat.
The accelerometers reproduce voice signals from vibrations at the throat or from
bony parts of the head, and are compatible with helmet or headset applications.
BF Series
Dampers are acoustic cloth screens for insertion inside acoustic tubing.
These damping elements are used between the speaker outlet and the ear canal
to smoothen the frequency response.
M M o o d d e e l l
BU-21771-000
BU-23173-000
BU-23842-000
BU-27135-000
M M o o d d e e l l
BF-1859-000
BF-1860-000
BF-1861-000
BF-1921-000
BF-1922-000
BF-1923-000
BF-1988-000
BF-1991-000
BF-1995-000
BF-1997-000
BF-1999-000
BF-3034-000
BF-3035-000
BF-3036-000
BF-3037-000
BF-3038-000
BF-3039-000
BF-3163-000
– Acoustic Dampers
– Accelerometer 7.87 x 5.54 (mm)
Thickness
4.06
4.06
2.24
2.24
Orange
Orange
Yellow
Yellow
Brown
Brown
Color
White
Green
White
Green
White
Green
Green
Grey
Grey
Red
Red
Red
•
•
•
•
•
•
•
•
•
Ceramic vibration transducer
High vibration sensitivity
Small size
Wide frequency range
Integral FET amplifier
High resistance to mechanical shock
Withstands severe environmental conditions
Smoothen and shape frequency response
Various acoustical resistances and sizes
1KHz (db re 1V/g)
Sensitivity @
Resistance (Ohms)
Nominal Acoustic
-45.0±4.5
-39.0±4.5
-40.0±4.0
-45.0±4.5
1000
1500
2200
3300
4700
1500
2200
1000
3300
2200
1500
1500
4700
680
680
680
330
330
DC Supply (V)
1.5
1.5
1.5
1.5
www.knowles.com
PLUG (mm)
2.08
2.08
2.08
2.08
2.08
2.08
2.08
--
--
--
--
--
--
--
--
--
--
--
Max. Current
Drain (uA)
300
50
50
50
SCREEN (mm)
1.12
1.12
1.12
1.78
1.78
1.78
1.78
1.78
1.78
1.37
1.12
--
--
--
--
--
--
--
Output Impedance
@1 KHz (Ohms)
Nominal
5200
5200
5200
5200
-25
-35
-45
-55
-65
100
2
3
4 5 6 7 8 9
Noise (dBre. 1V)
“A” Weighted
-103
-103
-103
-103
2
FREQUENCY (Hz)
3
4 5 6 7 8 9
1k
2
3
4 5 6 7 8 9
10k