si3201 Silicon Laboratories, si3201 Datasheet - Page 30

• Manufacturer Part Number: si3201
• Description: Proslic Programmable Cmos Slic With Ringing/battery Voltage Generation
• Manufacturer: Silicon Laboratories

Si3230
When
LF[2:0] = 100 (direct Register 64), the ProSLIC will go
into the ringing state and start the first ring. At the
expiration of RAT, the ProSLIC will turn off the ringing
waveform and will go to the on-hook transmission state.
At the expiration of RIT, ringing will again be initiated.
This process will continue as long as the two timers are
enabled and the Linefeed Control register is set to the
ringing state.
2.4.2. Sinusoidal Ringing
To configure the ProSLIC for sinusoidal ringing, the
frequency and amplitude are initialized by writing to the
following indirect registers: RCO, RNGX, and RNGY.
The equations for RCO, RNGX, RNGY are as follows:
where
and f = desired ringing frequency in hertz.
In selecting a ringing amplitude, the peak TIP-to-RING
ringing voltage must be greater than the selected on-
hook line voltage setting (VOC, direct Register 72). For
example, to generate a 70 V
equations are as follows:
30
Note: The ProSLIC uses registers that are both directly and indirectly mapped. A “direct” register is one that is mapped
RNGX
Common Mode Bias Adjust During Ringing
RNGX
directly. An “indirect” register is one that is accessed using the indirect access registers (direct registers 28 through
31).
RCO
=
the
1
-- -
4
=
×
Ringing initial phase
coeff
=
Ringing frequency
Ringing amplitude
ringing
1
-- -
4
----------------------- -
1
1 coeff
0.99211
×
–
+
coeff
RCO
=
coeff
0.00789
-------------------- -
1.99211
cos
RNGY
RNGY
state
=
×
=
×
⎛
⎝
Table 26. Registers for Ringing Generation (Continued)
---------------------- -
1000 Hz
(
cos
2 π 20
2
2
coeff
15
15
×
×
PK
2
⎛
⎝
)
×
---------------------- -
1000 Hz
=
15
=
is
=
Desired V
----------------------------------------------------------------------- -
×
20 Hz ringing signal, the
0
×
0
2 π f
⎞
⎠
32509
(
70
----- -
96
2
=
invoked
15
0.99211
=
)
⎞
⎠
376
=
PK
96 V
7EFDh
(
=
0 to 94.5 V
by
0177h
Preliminary Rev. 0.96
sinewave and period
Sets initial phase for
writing
15 to 100 Hz
0 to 94.5 V
0 to 22.5 V
trapezoid
)
for
In addition, the user must select the sinusoidal ringing
waveform by writing TSWS = 0 (direct Register 34,
bit 0).
2.4.3. Trapezoidal Ringing
In addition to the sinusoidal ringing waveform, the
ProSLIC
illustrates a trapezoidal ringing waveform with offset
V
To configure the ProSLIC for trapezoidal ringing, the
user should follow the same basic procedure as in the
Sinusoidal Ringing section, but using the following
equations:
RCO is a value which is added or subtracted from the
waveform to ramp the signal up or down in a linear
fashion. This value is a function of rise time, period, and
ROFF
Figure 13. Trapezoidal Ringing Waveform
.
V
TIP-RING
V
supports
ROFF
RNGX[15:0]
RNGY[15:0]
VCMR[3:0]
RNGX
RCO[15:0]
RNGY
RCO
=
t
=
RISE
trapezoidal
Desired V
-----------------------------------
=
1
-- -
2
×
-------------------------------- -
t
RISE
96 V
2 RNGX
Period
T=1/freq
×
×
Indirect Register 20
Indirect Register 21
Indirect Register 22
Indirect Register 40
8000
PK
×
×
ringing.
8000
(
2
15
)
time
Figure 13