Philips Semiconductors
Product specification
Low voltage versatile telephone
transmission circuit with dialler interface
TEA1067
handbook, full pagewidth
V
CC
MIC+
MIC+
MIC−
MIC+
(1)
MIC−
MIC−
V
EE
MGR086
(c)
(a)
(b)
(a) Magnetic or dynamic microphone. The resistor marked (1) may be connected to decrease
the terminating impedance.
(b) Electret microphone.
(c) Piezoelectric microphone.
Fig.11 Alternative microphone arrangements.
handbook, full pagewidth
(1)
(2)
QR+
QR+
QR−
QR+
QR−
QR+
QR−
QR−
V
EE
MGR087
(a)
(b)
(c)
(d)
(a) Dynamic earpiece with less than 450 Ω impedance.
(b) Dynamic earpiece with more than 450 Ω impedance.
(c) Magnetic earpiece with more than 450 Ω impedance. The resistor marked (1) may be connected
to prevent distortion (inductive load).
(d) Piezoelectric earpiece. The resistor marked (2) is required to increase the phase margin
(capacitive load).
Fig.12 Alternative receiver arrangements.
June 1990
16
NXP [ NXP ]
