C
MPO
+
10
1.0
8
2.2k
6
0.033
100
R
VC
100k
5
-
33k
200
4
1
R
MPO
10k
V =1.35VDC
B
1k
3
+
LS505
LS505
+
10
7
2
R
E
56
All resistors in ohms, all capacitors in farads unless otherwise stated
Fig. 3 Typical Hearing Aid Applications
47
46
7
6
5
4
VOLUME CONTROL RANGE (dB)
45
44
43
42
41
40
10
gm (
50
100
500
1k
5k
10k
)
Ω
3
2
1
0
10
50
100
500
1k
5k
10k
EXTERNAL RESISTANCE (Ω)
R
E
Ω
Fig. 5 GM
vs R
E
Ω
Ω
Fig. 4 Volume Control Range vs R
E
3.5
3.0
130
DIODES
DISCONNECTED
120
LOAD CURRENT
I
(mA)
2.5
OUTPUT (dBSPL)
50
100
500
1k
5kk
10k
L
2.0
1.5
1.0
0.5
0
10
110
100
90
80
30
40
50
60
70
80
90
100
110
EXTERNAL RESISTANCE R
E
(Ω)
INPUT (dBSPL)
Fig. 6 Load Current vs External Resistance
Fig. 7 I/O Characteristics
500 - 20 - 11
4
GENNUM [ GENNUM CORPORATION ]
