L9218A/G Low-Cost Line Interface
Data Sheet
November 2001
Electrical Characteristics (continued)
Table 6. Analog Pin Characteristics
Parameter
Differential PT/PR Current Sense (DCOUT):
Gain (PT/PR to DCOUT)
Offset Voltage at ILOOP = 0
Loop Closure Detector Threshold (RLCTH = 22.1 kΩ)1:
On- to Off-hook Threshold (scan mode)
Off- to On-hook Threshold (active mode)
Ring Trip Comparator:
Input Offset Voltage2
Internal Voltage Source
Current at Input RTSP3
RCVN, RCVP:
Input Bias Current
Input Resistance
Min
121
–100
8.8
6.0
—
–9.1
IN – 0.5
—
—
Typ
125
—
—
—
±10
–8.6
IN
–0.2
1
Max
Unit
129
V/A
100
mV
13.6
mA
10.2
mA
—
mV
–8.1
V
IN + 0.6
µA
–1
µA
—
MΩ
1. Loop closure threshold is programmed by resistor RLCTH from pin LCTH to pin DCOUT. The programming equation or relationship between
off-hook threshold and resistor value is different for active mode versus scan mode (see Applications section for more details).
2. This parameter is not tested in production. It is guaranteed by design and device characterization.
3. IN is the sourcing current at RTSN. Guaranteed if IN is within 5 µA to 30 µA.
10
Agere Systems Inc.