SI3201-X-FS SILABS [Silicon Laboratories], SI3201-X-FS Datasheet - Page 18

• Manufacturer Part Number: SI3201-X-FS
• Manufacturer: SILABS [Silicon Laboratories]

Si3233
2. Functional Description
The Si3233 ProSLIC
CMOS device that provides all the SLIC, DTMF, and
signal generation functions needed for a complete
analog telephone interface when connected to an
external codec. The ProSLIC performs all battery,
overvoltage, ringing, supervision, and test functions.
Unlike most monolithic SLICs, the Si3233 does not
require
supplies. It generates all necessary battery voltages
from a positive dc supply using its own dc-dc converter
controller. Two fully programmable tone generators can
produce DTMF tones, phase continuous FSK (caller ID)
signaling, and call progress tones. The Si3201 linefeed
interface IC performs all high voltage functions. The
Si3201 can also be replaced with low-cost discrete
circuits as shown in the typical application in Figure 6.
The Si3233 is designed to be used with Broadcom
devices
BCM6352. Special directions are required to interface
the Si3233 to other devices. Please contact Silicon
Laboratories for guidance.
The linefeed provides programmable on-hook voltage,
programmable off-hook loop current, reverse battery
operation, loop or ground start operation, and on-hook
transmission ringing voltage. Loop current and voltage
are continuously monitored using an integrated A/D
converter. Balanced 5 REN ringing with or without a
programmable dc offset is supported. Programmable
offset, frequency, waveshape, and cadence allow the
Si3233 to ring the widest variety of terminal devices and
to reduce external controller requirements.
2.1. Si3230 to Si3233 Differences
The hardware and software differences between the
Si3230 and the Si3233 are highlighted below for
customers migrating designs from the Si3230 to the
Si3233.
2.1.1. Hardware Changes
18
The Si3233 adds China and Japan impedances. See
"2.6. Two-Wire Impedance Matching" on page 34.
Pulse metering and DTMF detection are removed
from the Si3233.
External resistors R8 and R9 are changed from
470 Ω to 4.7 kΩ. See the typical application circuits
in Figure 3 on page 12 and Figure 6 on page 15.
The Si3233 adds PLL free-run mode. PLL free-run
mode is described in Section "2.8. PLL Free-run
Operation" on page 34.
externally
such
as
®
supplied
BCM1101,
is a feature-rich low-voltage
high-voltage
BCM3351/52,
Preliminary Rev. 0.5
battery
and
2.1.2. Software Changes
2.2. Linefeed Interface
The ProSLIC’s linefeed interface offers a rich set of
features and programmable flexibility to meet the
broadest application requirements. The dc linefeed
characteristics are software programmable; key current,
voltage, and power measurements are acquired in
realtime and provided in software registers.
2.2.1. DC Feed Characteristics
The ProSLIC has programmable constant voltage and
constant current zones as depicted in Figure 8. Open
circuit TIP-to-RING voltage (V
voltage zone and is programmable from 0 V to 94.5 V in
1.5 V steps. The loop current limit (I
constant current zone and is programmable from 20 mA
to 41 mA in 3 mA steps. The ProSLIC has an inherent
dc output resistance (R
The TIP-to-RING voltage (V
a programmable voltage (V
headroom to the positive-most terminal (TIP in forward
polarity states and RING in reverse polarity states) for
carrying audio signals. Table 19 summarizes the
parameters to be initialized before entering an active
state.
The sample rate for the two-tone oscillators has
changed from 8 kHz to 16 kHz, therefore, the audio
tone coefficient equation has changed. See "2.4.2.
Oscillator Frequency and Amplitude" on page 27 for
a complete description.
The Si3233 provides an automatic calibration routine
for gain mismatch. Manual calibration is not
required. Refer to "AN35: Si321x User's Quick
Reference Guide".
The Indirect Registers have been re-mapped. When
porting code from the Si3230 to the Si3233, the
indirect register access function needs to be
modified. See"4. Indirect Registers" on page 85.
V
(TIP-RING )
Figure 8. Simplified DC Current/Voltage
V
O C
(V)
Linefeed Characteristic
R
Constant
Voltage
O
O
Zone
=160
) of 160 Ω.
OC
Ω
CM
OC
) is offset from ground by
I
LIM
) to provide voltage
) defines the constant
Constant Current
LIM
I
LO O P
Zone
) defines the
(m A)