- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379310 > MC34216ADW (MOTOROLA INC) PROGRAMMABLE TELEPHONE LINE INTERFACE CIRCUIT WITH LOUDSPEAKER AMPLIFIER PDF資料下載
參數(shù)資料
MC34216A
11
MOTOROLA ANALOG IC DEVICE DATA
AC CHARACTERISTICS
Impedance
In Figure 5, the block diagram of the MC34216A
performing the ac impedance is depicted. As can be seen, it
is partly in common with the dc mask block diagram. The part
generating the dc mask is replaced by a dc voltage source
because for ac, this part has no effect.
Z21
T2
Z0
R5
V
C7
V
LAI
SAO
VO1
SAI
LAO
Gnd
R1
MC34216A
CC
O2
Line +
Line –
When calculating the ac loop, it can be derived that the set
impedance Zin equals:
Vline
Iline
+
+
+
+
Figure 5. AC Stage of the MC34216A
Zin
R1
1
Z0
Z21
R1 xZ0
Z21
As can be noticed, the formula for the ac impedance Zin
equals the formula for the dc slope in Regions 1 and 3.
However, because for the dc slopes the resistive part of Z0
and Z21 are used, the actual values for Zin and the dc slopes
do not have to be equal.
A complex impedance can be made by making either Z0
or Z21 complex. When Z0 is made complex to fit the set
impedance, the transmit characteristics will be complex as
well. The complex impedance is therefore preferably made
via the Z21 network. Because Z21 is in the denominator of
the Zin formula, Z21 will not be a direct copy of the required
impedance, but a derivative of it. Figure 6 shows the derived
network to be used for Z21.
Cb
Ra
Rb
Rv
Rv
Rw
Cw
SAO
LAI
Gnd
Rv
R1 x Z0
Rb – R1)
R1 x Z0 (Ra – R1)
4Rb (Ra
4Rb
2
x Cb
R1 x Z0
2(Ra
Rw
Rb – R1)
Cw
Figure 6. Derived Network for Z21 in Case
of Complex Set Impedance
Transmit
When on Pin LAI a current is injected, via the loop
depicted in Figure 5, a signal is created on the line. In this
way, the microphone signals and DTMF signals from the
internal generator are transmitted. It can be derived that the
signal voltage on the line (Vline) depends on the signal
current injected in LAI (ILAI) according to:
Vline
–ILAIx
Z0 x Zline
Zin
Zline
With this relation, a simplified replacement circuit can be
made for the transmit amplifier (see Figure 7). Here the
product of ILAI and Z0 is replaced by one voltage source.
Z
+
–
line
Zin
Vline
–ILAI*Z0
+
Figure 7. Replacement Diagram for the
Transmit Amplifier
The microphone signal current is derived from the
microphone signal according to the schematic in Figure 8.
Ru
Cmic
Cu
R
MIC
TXI
Microphone
Handset
Ku
Line AGC
Iu
MC34216A
Microphone Threshold
VCC
R
ILAI
TXI
Mic
Figure 8. Microphone Amplifier Input Stage
The input stage in Figure 8 consists of a current amplifier
with transfer Ku and impedance RTXI = 1.0 k
plus an
attenuator which reduces the signal current at high line
currents, the so–called line length regulated gain or line AGC.
This attenuator can be switched on/off via the microcontroller.
The input current Iu within the telephony speech band is
derived from the microphone signal according to:
Iu
Vu
Ru
RMic
RTXI
Vu
Ru
With: Vu = signal of the microphone only loaded with RMic.
The overall gain from microphone to line (ATX) now follows
as:
Vline
Vu
ATX
Ku
Z0 x Zline
Zin
Zline
Practically, the gain can only be varied with Z0, Ru and
RMic.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MC34216ADWF | PROGRAMMABLE TELEPHONE LINE INTERFACE CIRCUIT WITH LOUDSPEAKER AMPLIFIER |
| MC34216DW | ECONOLINE: RSZ/P - 1kVDC |
| MC34217 | Telephone tone ringer |
| MC34217P | ECONOLINE: RSZ/P - 1kVDC |
| MC3456P | DUAL TIMING CIRCUIT |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MC34224-071-1601 | 制造商:SPC Multicomp 功能描述:ROCKER SWITCH SPST BLACK/RED 制造商:SPC Multicomp 功能描述:ROCKER SWITCH, SPST, BLACK/RED 制造商:SPC Multicomp 功能描述:SWITCH, ROCKER, SPST, 16A, 250V, BLACK; Contact Configuration:SPST; Switch Operation:On-Off; Contact Current Max:20A; Contact Voltage AC Nom:250V; Switch Mounting:Panel; Actuator / Cap Color:Black; Actuator Style:Rocker; Series:MC34 ;RoHS Compliant: Yes |
| MC34226 | 制造商:SPC Multicomp 功能描述:FINGER GUARD 制造商:SPC Multicomp 功能描述:FINGER GUARD; For Use With:120mm Axial Fans; Fan Size:120mm; Fixing Centers:104.8mm; Guard Material:Steel; Accessory Type:Finger Guard; Color:Black; External Depth:5.2mm; External Height:117.3mm; External Width:117.3mm ;RoHS Compliant: Yes |
| MC34227 | 制造商:SPC Multicomp 功能描述:FINGER GUARD 制造商:SPC Multicomp 功能描述:FINGER GUARD; For Use With:127mm Axial Fans; Fan Size:127mm; Fixing Centers:113.3mm; Guard Material:Steel; Accessory Type:Finger Guard; Color:Black; External Depth:5.5mm; External Height:115.6mm; External Width:115.6mm ;RoHS Compliant: Yes |
| MC34229 | 制造商:SPC Multicomp 功能描述:FINGER GUARD 制造商:SPC Multicomp 功能描述:FINGER GUARD; For Use With:150mm Axial Fans; Fan Size:150 x 150mm; Fixing Centers:152.6mm; Guard Material:Steel; Accessory Type:Finger Guard; Color:Chrome; External Depth:6.4mm; External Height:163.6mm; External Width:163.6mm ;RoHS Compliant: Yes |
| MC34231-001-71 | 制造商:SPC Multicomp 功能描述:ROCKER SWITCH SPST BLACK I/O 制造商:SPC Multicomp 功能描述:ROCKER SWITCH, SPST, BLACK, I/O 制造商:SPC Multicomp 功能描述:SWITCH, ROCKER, SPST, 16A, 250V, BLACK; Contact Configuration:SPST; Switch Operation:On-Off; Contact Current Max:20A; Contact Voltage AC Nom:250V; Switch Mounting:Panel; Actuator / Cap Color:Black; Actuator Style:Rocker; Series:MC34 ;RoHS Compliant: Yes |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。