L9214A/G
Low-Cost Ringing SLIC
Preliminary Data Sheet
October 2001
Pin Information (continued)
Table 1. Pin Descriptions (continued)
28-Pin 32-Pin
48-Pin
MLCC
Symbol
Type
Name/Function
SOG
PLCC
16
20
23
24
25
26
TRGDET
O
Tip/Ring Ground Detect. When high, this open collector
output indicates the presence of a ring ground or a tip
ground. This supervision output may be used in ground
key or common-mode fault detection applications.
17
18
19
21
22
23
ICM
FB2
FB1
I
Common-Mode Current Sense. To program tip or ring
ground sense threshold, connect a resistor to VCC and
connect a capacitor to AGND to filter 50/60 Hz. If unused,
the pin is connected to ground.
—
—
Polarity Reversal Slowdown Capacitor. Connect a
capacitor from this node for controlling rate of battery
reversal. Also used for ringing, this pin cannot be left
open.
Polarity Reversal Slowdown Capacitor. Connect a
capacitor from this node for controlling rate of battery
reversal. Also used for ringing, this pin cannot be left
open.
20
21
24
25
29
31
PT
I/O
I/O
Protected Tip. The input to the loop sensing circuit and
output drive of the tip amplifier. Connect to loop through
overvoltage and overcurrent protection.
PR
Protected Ring. The input to the loop sensing circuit and
output drive of the ring amplifier. Connect to loop through
overvoltage and overcurrent protection.
22
23
24
25
26
26
27
28
29
30
33
34
35
36
38
B3
B2
B1
B0
ITR
I
I
I
I
I
State Control Input.
State Control Input.
State Control Input.
State Control Input.
Transmit Gain. Input to AX amplifier. Connect a resistor
from this node to VTX to set transmit gain. Gain shaping
for termination impedance with a COMBO I codec is also
achieved with a network from this node to VTX.
27
28
31
32
40
41
VTX
TXI
O
I
ac/dc Output Voltage. Output of internal AX amplifier.
The voltage at this pin is directly proportional to the differ-
ential tip/ring current.
ac/dc Separation. Input to internal AAC amplifier. Con-
nect a 0.1 µF capacitor from this pin to VTX.
Agere Systems Inc.
11
AGERE [ AGERE SYSTEMS ]
