L9312 Datasheet, PDF (10/40 Pages) Agere Systems – Line Interface and Line Access Circuit Forward Battery SLIC and Ringing Relay for TR-57 Applications

L9312 Line Interface and Line Access Circuit
Forward Battery SLIC and Ringing Relay for TR-57 Applications
Data Sheet
July 2001
Pin Information (continued)
Table 1. Pin Descriptions (continued)
Pin Symbol
37
ITR
38
NC
39
TXI
40 VITR
41 RCVP
42 RCVN
43 AGND
44
VCC
Type
I
—
I
O
I
I
G
P
Name/Function
Transmit Gain. A current output which is proportional to the differential current flow-
ing from tip to ring. Input to AX amplifier. Connect a resistor from this node to VITR to
set transmit gain to 300 Ω. Gain shaping for termination impedance with a COMBO I
codec is also achieved with a network from this node to VITR.
No Connect. May not be used as a tie point.
Transmit ac Input (Noninverting). Connect a 0.1 µF capacitor from this pin to VTX
for dc blocking.
Transmit ac Output Voltage. The output is a voltage that is directly proportional to
the differential ac tip/ring current. This output is connected via a proper interface net-
work to the codec.
Receive ac Signal Input (Noninverting). This high-impedance input controls the ac
differential voltage on tip and ring.
Receive ac Signal Input (Inverting). This high-impedance input controls the ac dif-
ferential voltage on tip and ring.
Analog Ground. Ground return for VCC current.
5 V Analog Power Supply. 5 V supply for analog circuitry.
Operating States
Input State Coding
Data control is via a parallel latched data control scheme. Data latches are edge-level sensitive. Data is latched in
when the LATCH control input goes low. Data must be set up 200 ns before LATCH goes low and held 50 ns after
LATCH goes high. While LATCH is low, the user should not change the data control inputs at B0, B1, and B2. The
data control inputs at B0, B1, and B2 may only be changed when LATCH is high. NSTAT supervision output is not
controlled by the LATCH control input.
Table 2. Control States
B2
B1
B0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
X
X
X
RESET
1
1
1
1
1
1
1
1
0
State
Scan
Powerup, forward battery
Unassigned
Unassigned
Ring
Unassigned
Unassigned
Disconnect, break before make
Disconnect, break before make
Table 3. Supervision Coding
Pin NSTAT
0 = off-hook or ring trip
1 = on-hook and no ring trip
Pin TRGDET
0 = ring ground
1 = no ring ground
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