SI3232 SILABS [Silicon Laboratories], SI3232 Datasheet - Page 20

• Manufacturer Part Number: SI3232
• Description: DUAL PROGRAMMABLE CMOS SLIC WITH LINE MONITORING
• Manufacturer: SILABS [Silicon Laboratories]

Si3232
4.3. DC Feed Characteristics
The Si3232 offers programmable constant voltage and
constant current operating regions as illustrated in
Figure 7 and Figure 8. The constant voltage region is
defined by the open-circuit voltage, V
programmable from 0 to 63.3 V in 1 V steps. The
constant current region is defined by the loop current
limit, I
0.87 mA steps. The Si3232 exhibits a characteristic dc
impedance of 320 Ω during Active mode.
20
LIM
, and is programmable from 18 to 45 mA in
TIP or
RING
C
Figure 6. Simplified Linefeed Architecture for TIP and RING Leads
AC
(Diagram illustrates either TIP or RING lead of a single channel)
Control
Audio
V
V
BATL
BATH
Metering
V
Control
R
Pulse
Audio
BAT
Loop
DC
A/D
D/A
OC
, and is
Preliminary Rev. 0.96
DSP
Current
Mirror
Σ
The TIP-RING voltage, V
programmable voltage, V
voltage headroom to the most positive terminal
(typically the TIP lead in normal polarity or the RING
lead in reverse polarity) for carrying audio signals. A
similar programmable voltage, V
offset between the most negative terminal and the
battery supply rail for carrying audio signals. (See
Figure 7.) The user-supplied battery voltage must have
sufficient amplitude under all operating states to ensure
sufficient headroom. The Si3200 may be powered by a
lower secondary battery supply, V
power dissipation when driving short loop lengths.
Control
Si3200
Monitor A/D
SLIC DAC
Loop
SLIC
Control
Battery
Select
A/D
D/A
Control
SLIC
OC
CM
, is offset from ground by a
V
, to provide sufficient
R
BAT
BAT
Si3232
OV
Sense
BATL
, is provided as an
, to reduce total