參數(shù)資料
型號: TEA1065T
廠商: NXP SEMICONDUCTORS
元件分類: 無繩電話/電話
英文描述: Versatile telephone transmission circuit with dialler interface
中文描述: TELEPHONE SPEECH CKT, PDSO24
封裝: PLASTIC, SO-24
文件頁數(shù): 10/28頁
文件大小: 154K
代理商: TEA1065T
March 1994
10
Philips Semiconductors
Product specification
Versatile telephone transmission circuit with
dialler interface
TEA1065
MUTE input
When MUTE = HIGH the DTMF input is enabled and the
microphone and receiving amplifier inputs are inhibited.
When MUTE = LOW or open-circuit the DTMF input is
inhibited and the microphone and receiving amplifier
inputs are enabled. Switching the MUTE input will cause
negligible clicks at the earpiece outputs and on the line. An
electrostatic discharge protection diode is connected
between pin MUTE and pin V
CC
(pins 20 and 21).
Dual-tone multifrequency input DTMF
When the DTMF input is enabled, dialling tones may be
sent onto the line. The voltage gain from DTMF to LN is
typ. 12.5 dB less than the gain of the microphone amplifier
and varies with R7 in the same way as the gain of the
microphone amplifier. This means that the tone level at the
DTMF input has to be adjusted after setting the gain of the
microphone amplifier. When R7 = 68 k
the gain is
typically 25.5 dB. The signalling tones can be heard in the
earpiece at a low level (confidence tone).
Receiving amplifiers: IR, QR
+
, QR
and GAR
The receiving amplifier has one input IR and two
complementary outputs, QR
+
(non-inverting) and
QR
(inverting). These outputs may be used for
single-ended or differential drive, depending on the type
and sensitivity of the earpiece used (see Fig.10). Gain
from IR to QR
+
is typically 31 dB with R4 = 100 k
, which
is sufficient for low-impedance magnetic or dynamic
earpieces which are suitable for single-ended drive. By
using both outputs (differential drive) the gain is increased
by 6 dB. Differential drive can be used when earpiece
impedance exceeds 450
as with high impedance
dynamic, magnetic or piezoelectric earpieces.
The output voltage of the receiving amplifier is specified for
continuous-wave drive. The maximum output voltage will
be higher under speech conditions where the ratio of peak
and RMS value is higher.
The gain of the receiving amplifier can be adjusted over a
range of
11 dB to
+
8 dB to suit the sensitivity of the
transducer that is used. The gain is proportional to external
resistor R4 connected between GAR and QR
+
.
Two external capacitors, C4 = 100 pF and C7 = 1 nF, are
necessary to ensure stability. A larger value of C4 may be
chosen to obtain a first-order low-pass filter. The “cut-off”
frequency corresponds with the time constant R4
×
C4.
Fig.10 Alternative receiver arrangements:
(a) dynamic earpiece with an impedance less than 450
;
(b) dynamic earpiece with an impedance more than 450
;
(c) magnetic earpiece with an impedance more than 450
, resistor (1) may be connected to prevent
distortion (inductive load);
(d) piezoelectric earpiece, resistor (2) is required to increase the phase margin (stability with capacitive
load).
handbook, full pagewidth
MBA554
(1)
QR
QR
+
5
4
VEE
16
QR
QR
+
5
4
QR
QR
+
5
4
(2)
QR
QR
+
5
4
(a)
(b)
(c)
(d)
相關(guān)PDF資料
PDF描述
TEA1066T Versatile telephone transmission circuit with dialler interface
TEA1068 Versatile telephone transmission circuit with dialler interface
TEA1068T Versatile telephone transmission circuit with dialler interface
TEA1069 Versatile speech/dialler/ringer with music-on-hold
TEA1069A Versatile speech/dialler/ringer with music-on-hold
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TEA1066T 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Versatile telephone transmission circuit with dialler interface
TEA1066TD 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Telephone Circuit (Support)
TEA1066TD-T 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Telephone Circuit (Support)
TEA1067 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Low voltage versatile telephone transmission circuit with dialler interface
TEA1067T 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Low voltage versatile telephone transmission circuit with dialler interface