AM79Q4457J ETC1 [List of Unclassifed Manufacturers], AM79Q4457J Datasheet - Page 29

• Manufacturer Part Number: AM79Q4457J
• Description: Quad Subscriber Line Audio Processing Circuit-Non-Programmable (QSLAC-NP) Devices
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

Note:
0.4
SLIC
SLIC
RSN
VTX
to
to
RGS2
0
0
1
1
Gr
R
Receive Gain Select 1 (RGS1) and
RX1
1
R1
R2
Receive Gain Select 2 (RGS2)
Table 3. Receive Gain Select
RGS1
(Am79Q4457 Device Only)
TX1
TX1
0
1
0
1
Net
Bal
1
C1
*
Net
Bal
TX1
1
Do Not Use
Gr
Gr
Gr
Net
Bal
C
2
l2
D-to-A Voltage Reference
=
l1
C2
*
=
=
Net
RX1
Bal
IN1
IN1
TX1
2
Gr3
Gr1
Gr2
V
BNS1
=
=
OUT1
Am79Q4457JC
=
------------------------------------------
R
1
------------------------------------------
R
REF3A
1.4
REF2A
1.4
Figure 9a. Am79Q4457JC Device
R
+
R
+
REF3A
R
REF2A
*Optional Bal Net Connection
R
REF3B
REF2B
(Channel 1 Shown)
SLAC Products
I1
V1
Multiplexer
3 to 1
D/A
V
Multiplexer
Vo
REF
A/D
I2
3 to 1
I
REF
Gain Settings for the Am79Q5457 Device
The transmit and receive gains for each of the four
channels are set for the Am79Q5457 device similarly
to those of the Am79Q4457 device. The Am79Q5457
device has only one I
shown in Figure 9b, and only one gain setting is avail-
able. The transmit gain is a function of the reference
current set up by the R
input resistor, and is set by the following equation:
The receive gain Gr through the QSLAC-NP device is
equal to 1 and is not adjustable. However, this gain typ-
ically is set by choice of component values in the SLIC
portion of the circuit.
IO
1
2
1
I3
V2
V3
3
2
V
I
I
I
REF1
REF2
REF3
4
3
REF1
4
RGS1
TGS1
TGS2
V
RGS2
I
REF
to
REF
Gt
REF
=
REF1
output and one V
3 R
---------------------- -
I
I
I
V
REF3
V
REF1
REF2
V
R1
REF1
REF3
REF2
resistor and by the R
TX1
REF1
R
R
R
C
REF2A
REF3A
REF1
FIL
R
R
REF2B
REF3B
20031A–010
REF
input as
29
TX1