SI3201-GSR Silicon Laboratories Inc, SI3201-GSR Datasheet - Page 33

• Manufacturer Part Number: SI3201-GSR
• Description: SLIC 3.3V/3.3V/3.3V/5V/5V/5V
• Manufacturer: Silicon Laboratories Inc

Specifications of SI3201-GSR

• Lead Free Status / Rohs Status: Compliant

2.1.9. Linefeed Calibration
An internal calibration algorithm corrects for internal and
external component errors. The calibration is initiated by
setting the CAL bit in direct Register 96. Upon
completion of the calibration cycle, this bit is
automatically reset.
It is recommended that a calibration be executed
following system powerup. Upon release of the chip
reset, the ProSLIC is in the Open state. After powering
up the dc-dc converter and allowing it to settle for time
(T
calibrations may be performed, but only one calibration
should be necessary as long as the system remains
powered up.
During calibration, V
controlled by the calibration engine to provide the
correct external voltage conditions for the algorithm.
Calibration should be performed in the On-Hook state.
RING or TIP must not be connected to ground during
the calibration.
When using the Si3201, automatic calibration routines
for RING gain mismatch and TIP gain mismatch should
not be performed. Instead of running these two
calibrations automatically, consult “AN35: Si321x User’s
Quick Reference Guide”, and follow the instructions for
manual calibration.
2.2. Battery Voltage Generation and
The ProSLIC integrates a dc-dc converter controller that
dynamically regulates a single output voltage. This
mode eliminates the need to supply large external
battery voltages. Instead, it converts a single positive
input voltage into the real-time battery voltage needed
for any given state according to programmed linefeed
parameters.
2.2.1. DC-DC Converter General Description
The dc-dc converter dynamically generates the large
negative voltages required to operate the linefeed
interface. The ProSLIC acts as the controller for a buck-
boost dc-dc converter that converts a positive dc
voltage into the desired negative battery voltage. In
addition to eliminating external power supplies, this
allows the ProSLIC to dynamically control the battery
voltage to the minimum required for any given mode of
operation.
Two different dc-dc circuit options are offered: a BJT/
inductor version and a MOSFET/transformer version.
Due to the differences on the driving circuits, there are
two different versions of the ProSLIC. The Si321x
supports the BJT/inductor circuit option, and the
Si321xM version supports the MOSFET solution. The
SETTLE
Switching
) the calibration can be initiated. Additional
BAT
, V
TIP
, and V
RING
voltages are
Rev. 1.0
only difference between the two versions is the polarity
of the DCFF pin with respect to the DCDRV pin. For the
Si321x, DCDRV and DCFF are opposite polarity. For
the Si321xM, DCDRV and DCFF are the same polarity.
Table 26 summarizes these differences.
Extensive design guidance on each of these circuits can
be obtained from “AN45: Design Guide for the Si3210
DC-DC Converter” and from an interactive dc-dc
converter design spreadsheet. Both of these documents
are available on the Silicon Laboratories website
(www.silabs.com).
2.2.2. BJT/Inductor Circuit Option Using Si321x
The BJT/Inductor circuit option, as defined in Figure 13
on page 23, offers a flexible, low-cost solution.
Depending on selected L1 inductance value and the
switching frequency, the input voltage (V
from 5 V to 30 V. By nature of a dc-dc converter’s
operation, peak and average input currents can become
large with small input voltages. Consider this when
selecting the appropriate input voltage and power rating
for the V
For this solution, a PNP power BJT (Q7) switches the
current flow through low ESR inductor L1. The Si3216
uses the DCDRV and DCFF pins to switch Q7 on and
off. DCDRV controls Q7 through NPN BJT Q8. DCFF is
ac-coupled to Q7 through capacitor C10 to assist R16 in
turning off Q7. Therefore, DCFF must have opposite
polarity to DCDRV, and the Si321x (not Si321xM) must
be used.
2.2.3. MOSFET/Transformer Circuit Option Using
The MOSFET/transformer circuit option, as defined in
Figure 14 on page 24, offers higher power efficiencies
across a larger input voltage range. Depending on the
transformer’s primary inductor value and the switching
frequency, the input voltage (V
to 35 V. Therefore, it is possible to power the entire
ProSLIC solution from a single 3.3 V or 5 V power
supply. By nature of a dc-dc converter’s operation, peak
and average input currents can become large with small
input voltages. Consider this when selecting the
appropriate input voltage and power rating for the V
Notes:
Table 26. Si321x and Si321xM Differences
1. DCFF signal polarity with respect to DCDRV signal.
2. Direct Register 93, bit 5; This is a read-only bit.
Si321xM
Device
Si321x
Si321xM
DC
power supply.
DCFF Signal
= DCDRV
= DCDRV
Polarity
DC
) can range from 3.3 V
Si3216
DC
DCPOL
) can range
0
1
DC
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