L6726 Unisonic Technologies, L6726 Datasheet - Page 8

no-image

L6726

Manufacturer Part Number
L6726
Description
UNIVERSAL SPEECH CIRCUIT
Manufacturer
Unisonic Technologies
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
L6726A
Manufacturer:
TOS
Quantity:
898
Part Number:
L6726A
Manufacturer:
ST
0
Part Number:
L6726A
Manufacturer:
ST
Quantity:
20 000
Part Number:
L6726AD
Manufacturer:
ST
0
Part Number:
L6726AD
Manufacturer:
ST
Quantity:
20 000
Part Number:
L6726ATR
Manufacturer:
FUJI
Quantity:
130
Part Number:
L6726ATR
Manufacturer:
ST
0
Part Number:
L6726ATR
Manufacturer:
ST
Quantity:
20 000
Company:
Part Number:
L6726ATR
Quantity:
9 000
Company:
Part Number:
L6726ATR
Quantity:
6 000
Company:
Part Number:
L6726ATR
Quantity:
989
Part Number:
L6726D
Manufacturer:
ST
0
www.DataSheet4U.com
L6726
Refer to figure 6.
Gain regulation (R1, R2):
No regulation
Set for short line gain.
All feedings
Regulation:
48V, 2·200Ω
48V, 2·400Ω
36V, 2·500Ω
Impedance to line (R3, C1, C2):
The time constant R3, C1 cannot be allowed to be too small. If the time constant is to small, distortion at low
frequencies may be generated.
If R3 is changed this will change the DC-characteristic too, which set by the voltage at pin 4. The input current at pin
4 is about 1mA
Microphone selection (M1, R16):
The input impedance between pin 12 and 13 is about 1.7kΩ with typical variation ±20%
Transmitting gain and frequency response (R4, R5, C3, C4):
reduction of the gain is wanted. Input impedance at pin 3 is about 17 kΩ with typical variation ±20%.The sum of the
resistors R4 and R5 must not be less than 35 kΩ because of DC-current to ground. Below is some simple variations
of this network. (See figure 7).
DC-characteristics (R6):
protection of the circuit, the transmitter, the gain regulation and side tone. Common values are 47 Ω to 100 Ω.
balance together the signals that go two different ways from the transmitter output stage one from pin1 and the other
from pin2. The balance network consist of R8, R9 and C5.
R12, R13, C6, (R10, R11):
of the network, see the network for the transmitter (R4, R5, C3)
REC, R14:
be placed between pin 17 and 18.See figure 16.
These resistors set the starting point for the gain-and side tone regulation.
Input impedance pin 6 is about 5.5 kΩ±20%.
Below are some typical values for R1 and R2, for some different supplies from telephone stations.
C1 in series with R3 and those in parallel with C2 give the impedance to the line from the set.
C2 must normally be there for the interference too.
The network is optimized with regard to the return loss.
The microphone can be either dynamic, magnetic or electrets. See figures 12,14 and 15.
The network gives the amplification and frequency response for the transmitter. R5 is used when a greater
Sets the DC-characteristic and take care of some of the supplied power. The resistor have also function with the
Side tone level, receiving gain and frequency response.(R7,R8,R9,R10,R11,C5):
The network sets the side tone balance. The network in the application is one of many possibilities. R10 and R11
The example is not optimized to any specified line, it is only given to show the principle.
Fig8, 9 and 10 are examples of balance networks. Fig.10 is especially suited for lines with high current supply.
The networks gives the gain and frequency response for the receiver.
Input impedance at pin 15 is about 38 kΩ with a typical variation of ±20%.For different possibilities for the design
R14 generates the output impedance to the magnetic earphone (fig.11). If a dynamic earphone is used it should
APPLICATION INFORMATION
Battery feed
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
R1
180kΩ
LINEAR INTEGRATED CIRCUIT
22kΩ
R2
47~100Ω
100Ω
47Ω
75Ω
R6
QW-R108-015,B
8 of 13

Related parts for L6726