L9216B/H
Preliminary Data Sheet
September 2001
High-Voltage Ringing SLIC with Ground Start
performance, it is best to operate the codec at a higher
gain level. If the SLIC then provides a high gain, the
SLIC output may be saturated causing clipping distor-
tion of the signal at tip and ring. To avoid this situation,
with a higher gain SLIC, external resistor dividers are
used. These external components are not necessary
with the lower gain offered by the L9216. See the Appli-
cations section of this data sheet for more information.
Description (continued)
The L9216 uses a voltage feed-current sense architec-
ture; thus, the transmit gain is a transconductance. The
L9216 transconductance is set via a single external
resistor, and this device is designed for optimal perfor-
mance with a transconductance set at 300 V/A.
The L9216 offers an option for a single-ended to differ-
ential receive gain of either 8 or 2. These options are
mask programmable at the factory and are selected by
choice of code.
The L9216 is internally referenced to 1.5 V. This refer-
ence voltage is output at the VREF output of the device.
The SLIC output VITR is also referenced to 1.5 V;
therefore, it must be ac coupled to the codec input.
However, the SLIC inputs RCVP/RCVN are floating
inputs. If there is not feedback from RCVP/RCVN to
VITR, RCVP/RCVN may be directly coupled to the
codec output. If there is feedback from RCVP/RCVN to
VITR, RCVP/RCVN must be ac coupled to the codec
output.
A receive gain of 8 is more appropriate when choosing
a first-generation type codec where termination imped-
ance, hybrid balance, and overall gains are set by
external analog filters. The higher gain is typically
required for synthesization of complex termination
impedance.
A receive gain of 2 is more appropriate when choosing
a third-generation type codec. Third-generation codecs
will synthesize termination impedance and set hybrid
balance and overall gains. To accomplish these func-
tions, third-generation codecs typically have both ana-
log and digital gain filters. For optimal signal to noise
The L9216 is packaged in a 28-pin PLCC package.
Use L9216B for gain of eight applications and L9216H
for gain of two applications.
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Agere Systems Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
