SI3201-FS View Datasheet(PDF) - Silicon Laboratories

Part Name

Description

Manufacturer

SI3201-FS

PROSLIC® PROGRAMMABLE CMOS SLIC WITH RINGING/BATTERY VOLTAGE GENERATION

Silicon Laboratories 

Si3230

2. Functional Description

The Si3230 ProSLIC® is a single low-voltage CMOS

device that provides all the SLIC, DTMF detection, 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 Si3230 does not

require externally supplied high-voltage battery

supplies. Instead, 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.

DTMF decoding and pulse metering signal generation

are also integrated. The Si3201 linefeed interface IC

performs all high voltage functions. As an option, the

Si3201 can also be replaced with low-cost discrete

components as shown in the typical application circuit in

Figure 6.

The 3230 is primarily meant to be used with Broadcom

devices BCM1101, BCM3351/52, and BCM6352.

Special directions for interfacing and operating the

Si3230 are needed. Please contact Silicon Laboratories

for guidance with other applications.

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 integrated. The available

offset, frequency, waveshape, and cadence options are

designed to ring the widest variety of terminal devices

and to reduce external controller requirements.

2.1. Linefeed Interface

The ProSLIC’s linefeed interface offers a rich set of

features and programmable flexibility to meet the

broadest applications requirements. The dc linefeed

characteristics are software programmable; key current,

voltage, and power measurements are acquired in

realtime and provided in software registers.

2.1.1. DC Feed Characteristics

The ProSLIC has programmable constant voltage and

constant current zones as depicted in Figure 8. Open

circuit TIP-to-RING voltage (VOC) defines the constant

voltage zone and is programmable from 0 V to 94.5 V in

1.5 V steps. The loop current limit (ILIM) defines the

constant current zone and is programmable from 20 mA

to 41 mA in 3 mA steps. The ProSLIC has an inherent

dc output resistance (RO) of 160 Ω.

V(TIP-RING) (V)

VOC

Constant

Voltage

Zone

RO=160 Ω

Constant Current

Zone

ILIM

ILOOP(m A)

Figure 8. Simplified DC Current/Voltage

Linefeed Characteristic

The TIP-to-RING voltage (VOC) is offset from ground by

a programmable voltage (VCM) to provide voltage

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.

Table 19. Programmable Ranges of DC

Linefeed Characteristics

Parameter Programmable Default Register Location*

Range

Value

Bits

ILIM

20 to 41 mA 20 mA ILIM[2:0]

Direct

Register 71

VOC

0 to 94.5 V

48 V VOC[5:0]

Direct

Register 72

VCM

0 to 94.5 V

3V

VCM[5:0]

Direct

Register 73

*Note: The ProSLIC uses registers that are both directly

and indirectly mapped. A “direct” register is one that

is mapped directly.

2.1.2. Linefeed Architecture

The ProSLIC is a low-voltage CMOS device that uses

either an Si3201 linefeed interface IC or low-cost

external components to control the high voltages

required for subscriber line interfaces.

The ProSLIC uses both voltage and current sensing to

control TIP and RING. DC and AC line voltages on TIP

and RING are measured through sense resistors RDC

and RAC, respectively. The ProSLIC uses linefeed

transistors QP and QN to drive TIP and RING. QDN

isolates the high-voltage base of QN from the ProSLIC.

The ProSLIC measures voltage at various nodes in

18

Preliminary Rev. 0.96

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