SA3291 Datasheet, PDF (8/20 Pages) ON Semiconductor – Preconfigured Wireless DSP System for Hearing Aids

AYRE SA3291
TYPICAL APPLICATIONS
VB
3
1
3k75
22
3k75
2
3k75
19
3k75
21
15
14
Voltage
Regulator
A/D
M
U
X
A/D
Programming
Interface
Clock
Generator
MIC/TCOIL
COMP
Adaptive
Directional
Microphone
or
FrontWave
Pre
Biquad
Filters
Frequency
Band
Analysis
Wireless
Audio/Data
6
8
Acoustic
Indicators
18
9
POR Circuitry
11
Post
Σ
Biquad
Filters
* _Feedback 3 & 4
Canceller
**
Cross
Fader
Peak
Clipper
Noise Generator
and Shaper
12
D/A
Hbridge
13
10
128 bands
AGCO
Environmental
Classification
Volume
Control
Σ ^Wideband
Gain
Control
4
A/D
Post
Biquad
Filters
1&2
Frequency
Band
Synthesis
Control
(MS/DIGVC) 17
16
WDRC (1,2,4,6 or 8 Channels)
Noise Reduction (128 bands)
Graphic EQ (16 bands)
Data
Logging
EEPROM
7 20
OUT
LP Filter
200k
* If Input Mode = 1 mic omni, mic + telecoil, mic + DAI
** If Input Mode = 2 mic omni, rear only, directional
Note: All resistors in ohms and all capacitors in farads, unless otherwise stated.
Figure 3. Test Circuit
VB
3
1
22
2
19
T−coil
21
15
14
Voltage
Regulator
A/D
M
U
X
A/D
Programming
Interface
Clock
Generator
Acoustic
Indicators
18
9
POR Circuitry
11
MIC/TCOIL
COMP
Post
Biquad
Filters
Adaptive
*
Feedback
Directional
Canceller
Microphone _**
or
3&4
FrontWave
AGCO
Σ
Cross
Fader
Peak
Clipper
Noise Generator
and Shaper
Volume
Control
Σ ^Wideband
Gain
Pre
Biquad
Filters
Environmental
Classification
Post
Biquad
Filters
1&2
D/A
Hbridge
Control
A/D
12
13
Zero Biased
Receiver
10
4
Frequency
Band
Analysis
128 bands
Frequency
Band
Control
(MS/DIGVC)
17
Synthesis
16
Wireless
Audio/Data
WDRC (1,2,4,6 or 8 Channels)
Noise Reduction (128 bands)
Graphic EQ (16 bands)
Data
Logging
EEPROM
6
8
NFMI coil
7 20
* If Input Mode = 1 mic omni, mic + telecoil, mic + DAI
** If Input Mode = 2 mic omni, rear only, directional
Note: All resistors in ohms and all capacitors in farads, unless otherwise stated.
Figure 4. Typical Application Circuit
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