SI3220-KQ Silicon Laboratories Inc, SI3220-KQ Datasheet - Page 33

• Manufacturer Part Number: SI3220-KQ
• Description: IC SLIC/CODEC DUAL-CH 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: ProSLIC®r

Specifications of SI3220-KQ

• Package / Case: *
• Function: Subscriber Line Interface Concept (SLIC), CODEC
• Interface: GCI, PCM, SPI
• Number Of Circuits: 2
• Voltage - Supply: 3.3V, 5V
• Current - Supply: 65mA
• Power (watts): 941mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Includes: Battery Switching, BORSCHT Functions, DTMF Generation and Decoding, FSK Tone Generation, Modem and Fax Tone Detection
• Product: Telecom
• Supply Voltage (min): 3.13 V
• Supply Current: 22 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Number Of Channels: 2
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Power Monitoring and Power Fault
Detection
The Dual ProSLIC line monitoring functions can be
used to protect the high-voltage circuitry against
excessive power dissipation and thermal overload
conditions. This protection scheme can be implemented
in a number of different ways depending on the
application circuit used. When the Si3200 linefeed
interface chip is used, an on-chip thermal monitor diode
provides realtime Si3200 die temperature data to the
Si3220/3225. The Dual ProSLIC devices also have the
ability to prevent thermal overloads by regulating the
total power inside the Si3200 or in each of the external
bipolar transistors (if using a discrete linefeed circuit).
The DSP engine performs all power calculations and
Transistor Power Equations
(Using Discrete Transistors)
When using the Si3220 or Si3225 along with discrete
bipolar transistors, it is possible to control the total
power of the solution by regulating the power in each
discrete transistor individually. Figure 19 illustrates the
basic transistor-based linefeed circuit for one channel.
The power dissipation of each external transistor is
estimated based on the A/D sample values. The
approximate power equations for each external BJT are
as follows:
P
P
Q1
Q2
≅ V
≅ V
R6*gain
CE1
CE2
RBQ6
ITIPN
x I
x I
Q10
Q1
Q2
Q4
1.74k
≅ (V
≅ (V
TIP
RING
Figure 19. Discrete Linefeed Circuit for Power Monitoring
+ 0.75 V) x (I
Q8
+ 0.75 V) x (I
ITIPP
Q1
Q2
)
Q1
Q6
)
R6
82.5
TIP
Preliminary Rev. 0.91
provides the ability to automatically transition the device
into the OPEN state and generate a power alarm
interrupt when excessive power is detected. Table 20 on
page 35 describes the register and RAM locations used
for power monitoring.
Thermometer-Based Si3200 Power Monitor
The Si3200 includes an on-chip analog thermal sensing
diode that provides realtime die temperature data to the
Si3220/3225 provided the THERMSEL bit is set to 1.
The analog thermometer has a built in temperature
threshold which, when exceeded, turns off the Si3200
and asserts the STAT bit of the THERM register. The
internal temperature threshold is set to approximately
140 °C to maintain optimal device reliability.
P
P
P
P
The maximum power threshold for each device is
software programmable and should be set based on the
characteristics of the transistor package, PCB design,
and available airflow. If the peak power exceeds the
programmed threshold for any device, the power alarm
bit is set for that device. Each external bipolar has its
own register bit (PQ1S–PQ6S bits of the IRQVEC3
register) which goes high on a rising edge of the
RING
Q3
Q4
Q5
Q6
≅ V
≅ V
≅ V
≅ V
82.5
R7
Q2
Q5
CE3
CE4
CE5
CE6
IRINGP
x I
x I
x I
x I
Q3
Q4
Q5
Q6
≅ (V
≅ (V
≅ (V
≅ (V
BAT
BAT
BAT
BAT
Q7
Si3220/Si3225
– R106 x I
– R103 x I
– V
– V
RING
TIP
1.74k
– R103 x I
Q3
– R106 x I
Q9
Q5
Q6
IRINGN
RBQ5
R7*gain
) x (I
) x (I
Q6
Q3
Q4
Q5
) x (I
)
)
) x (I
Q6
VBAT
Q5
)
33
)