U4091BM TEMIC Semiconductors, U4091BM Datasheet - Page 17

• Manufacturer Part Number: U4091BM
• Description: Programmable Telephone Audio Processor
• Manufacturer: TEMIC Semiconductors

Switch Matrix
The switch matrix has 5 inputs and 5 outputs. Every pair
of input and output except AGCO and AGCIN can be
connected. The inputs and outputs used must be enabled.
If 2 or more inputs are switched to an output, the sum of
the inputs is available at the output.
The inputs MIC and LRX have offset cancellers with a
3-dB corner frequency of 270 Hz. AMPB has a 60-k
input impedance. The TXO output has a digitally-
programmable gain stage with a gain of 2, 3 to 9 dB
depending on AGATX0 (LSB), AGATX1, AGATX2
(MSB) and a first order low-pass filter with 0.5 dB
damping at 3300 Hz and 3 dB damping at 9450 Hz. The
outputs RXLS, EPO and AMREC have a gain of 0 dB.
The offset at the outputs of the matrix is less than 30 mV.
If a switch is open, the path has a damping of more than
60 dB.
AGC
Rev. A1, 02-Jun-98
AGCO
AGCI
O5
I5
Figure 18. Diagram for switch matrix
AMREC EPO RXLS
O4
AMPB LRX DTMF MIC
I4
canceller
O3
Offset
I3
O2
I2
LTX
STO
canceller
Lowpass
O1
2.9 dB
Offset
I1
Target Specification
–10 dB
AGATX0
AGATX1
AGATX2
TXO
14596
W
Table 3. Table of bits and corresponding switches
R2
R3
R4
Register
R2B0 I1O1
R2B1 I1O2
R2B2 I1O3
R2B3 I1O4
R2B4 I1O5
R2B5 I2O1
R2B6 I2O2
R2B7 I2O3
R3B0 I2O4
R3B1 I2O5
R3B2 I3O1
R3B3 I3O2
R3B4 I3O3
R3B5 I3O4
R3B6 I3O5
R3B7 I4O1
R4B0 I4O2
R4B1 I4O3
R4B2 I4O4
R4B3 I4O5
R4B4 I5O1
R4B5 I5O2
R4B6 I5O3
R4B7 I5O4
No.
Name
Switch on MIC / LTX
Switch on MIC / RXLS
Switch on MIC / EPO
Switch on MIC / AMREC
Switch on MIC / AGCI
Switch on DTMF / LTX
Switch on DTMF / RXLS
Switch on DTMF / EPO
Switch on DTMF / AMREC
Switch on DTMF / AGCI
Switch on LRX / LTX
Switch on LRX / RXLS
Switch on LRX / EPO
Switch on LRX / AMREC
Switch on LRX / AGCI
Switch on AMPB / LTX
Switch on AMPB / RXLS
Switch on AMPB / EPO
Switch on AMPB / AMREC
Switch on AMPB / AGCI
Switch on AGCO / LTX
Switch on AGCO / RXLS
Switch on AGCO / EPO
Switch on AGCO / AMREC
U4091BM
Description
17 (29)