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PBL 385 70
4
Figure 5. Pin configuration.
18-pin DIP
20-pin SO
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+L
TO
TI
+C
Mute
GR
DCS
DCO
DR
RI
-L
MI 2
MI 1
MO
1
2
3
4
5
6
7
8
16
15
14
13
12
11
DCC
DI
9
10
RE 2
RE 1
18
17
1
2
3
4
5
6
7
8
19
18
17
16
15
14
13
+L
TO
TI
+C
Mute
GR
DCS
DCO
RE 2
RE 1
DR
RI
-L
MI 2
MI 1
MO
9
12
10
11
DCC
NC
DI
NC
20
Pin Descriptions
Refer to figure 5.
DIP
SO
Name
Function
1
1
+L
Output of the DC-regulator and transmit amplifier, connected to the line through a polarity
guard diode bridge.
2
2
TO
Output of the transmit amplifier, connected through a resistor of 47 to 100 ohm to -L,
sets the DC-characteristics of the circuit. The output has a low AC output impedance and the
signal is used to drive a side tone balancing network.
3
3
TI
Input of transmit amplifier. Input impedance 17 kohm
±
20 %.
4
4
+C
Positive power supply terminal for most of the circuitry inside the PBL 385 70 (about 1 mA current
consumption). The +C pin must be connected to a decoupling capacitor of 47
μ
F to 150
μ
F.
5
5
Mute
When low, speech circuit is muted and the DTMF input is enabled. Maximum voltage (at mute) is
0.3 V, current sink requirement of external driver is min. 50
μ
A.
6
6
GR
Control input for the gain regulation circuitry.
7
7
DCS
Sense input to the DC-supply.
8
8
DC1
Output from the DC-supply.
9
9
DC2
Control of the DC-supply.
10
12
DI
Input for the DTMF-signal. Input impedance is 25 kohm
±
20 %.
11
13
MO
Output of the microphone amplifier or DTMF-amplifier.
12
14
MI 1
Inputs to the microphone amplifier. Input impedance 1.7 kohm
±
20 %.
13
15
MI 2
14
16
-L
The negative power terminal, connected to the line through a polarity guard diode bridge.
15
17
RI
Input of receiver amplifier. Input impedance is 38 kohm
±
20 %.
16
18
DR
Control input for the receiver amplifier driving capacity.
17
19
RE 1
Receiver amplifier outputs. Output impedance is approximately 3 ohm.
18
20
RE 2
10
NC
11
NC