PBL 385 70
+L
1
TO
2
TI
3
+C
4
Mute
5
GR
6
DCS
7
DCO
8
DCC
9
18
RE 2
17
RE 1
16
DR
15
RI
14
-L
13
MI 2
12
MI 1
11
MO
10
DI
+L
TO
TI
+C
Mute
GR
DCS
DCO
DCC
NC
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
RE 2
RE 1
DR
RI
-L
MI 2
MI 1
MO
DI
NC
18-pin DIP
20-pin SO
Figure 5. Pin configuration.
Pin Descriptions
Refer to figure 5.
DIP SO
Name
1
2
1
2
+L
TO
Function
Output of the DC-regulator and transmit amplifier, connected to the line through a polarity
guard diode bridge.
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.
Input of transmit amplifier. Input impedance 17 kohm
±
20 %.
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
µF
to 150
µF.
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
µA.
Control input for the gain regulation circuitry.
Sense input to the DC-supply.
Output from the DC-supply.
Control of the DC-supply.
Input for the DTMF-signal. Input impedance is 25 kohm
±
20 %.
Output of the microphone amplifier or DTMF-amplifier.
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
3
4
5
6
7
8
9
12
13
14
15
16
17
18
19
20
10
11
TI
+C
Mute
GR
DCS
DC1
DC2
DI
MO
MI 1
MI 2
-L
RI
DR
RE 1
RE 2
}
}
Inputs to the microphone amplifier. Input impedance 1.7 kohm
±
20 %.
The negative power terminal, connected to the line through a polarity guard diode bridge.
Input of receiver amplifier. Input impedance is 38 kohm
±
20 %.
Control input for the receiver amplifier driving capacity.
Receiver amplifier outputs. Output impedance is approximately 3 ohm.
NC
NC
4
ERICSSON [ ERICSSON ]
