SI3225-KQ Silicon Laboratories Inc, SI3225-KQ Datasheet - Page 34

• Manufacturer Part Number: SI3225-KQ
• Description: IC SLIC/CODEC DUAL-CH 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: ProSLIC®r

Specifications of SI3225-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: SLIC
• 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

Si3220/Si3225
comparator output and remains high until the user
clears it. Each transistor power alarm bit is also
maskable by setting the PQ1E–PQ6E bits in the
IRQEN3 register.
Si3200 Power Calculation
When using the Si3200, it is also possible to control
thermal temperature rise by calculating the total power
dissipated within the IC. This case is similar to the
Transistor Power Equations case, with the exception
that the total power from all transistor devices is
dissipated within the same package enclosure and the
total power result is placed in the PSUM RAM location.
The power calculation is derived using the following set
of equations:
P
P
P
P
P
P
PSUM = total dissipated power = P
P
Power Filter and Alarms
The power calculated during each A/D sample period
must be filtered before being compared to a user
programmable maximum power threshold. A simple
digital low pass filter is used to approximate the
transient thermal behavior of the package, with the
output of the filter representing the effective peak power
within the package or, equivalently, the peak junction
temperature.
For Q1, Q2, Q3, Q4 in SOT23 and Q5, Q6 in SOT223
packages, the settings for thermal low pass filter poles
and power threshold settings are (for an ambient
temperature of 70 °C) calculated as follows. If the
thermal time constant of the package is τ
decimal values of RAM locations PLPF12, PLPF34, and
PLPF56 are given by rounding to the next integer the
value given by the equation:
Where 4096 is the maximum value of the 12-bit plus
sign RAM locations PLPF12, PLPF34, and PLPF56,
and 800 is the power calculation clock rate in Hz. The
equation is an excellent approximation of the exact
equation for τ
equations in mind, the values of the RAM locations
34
Q1
Q2
Q3
Q4
Q5
Q6
Q4
≅ (V
≅ (V
≅ (V
≅ (V
≅ (V
≅ (V
+ P
Q5
TIP
RING
BAT
BAT
BAT
BAT
PLPFxx (decimal value)
+ P
+ 0.75 V) x I
+ 0.75 V) x I
+ 0.75 V) x I
– V
– V
thermal
+ 0.75 V) x I
Q6
RING
TIP
) x I
= 1.25 ms … 5.12 s. With the above
) x I
Q6
Q1
Q5
Q3
Q4
Q2
=
------------------------------------
800 τ
Q1
4096
×
+ P
thermal
Q2
thermal
Preliminary Rev. 0.91
+ P
, the
Q3
+
PLPF12, PLPF34, and PLPF56 are presented below:
PTH12 = power threshold for Q1, Q2 = 0.21 W (0x0480)
PTH34 = power threshold for Q3, Q4 = 0.21 W (0x2600)
PTH56 = power threshold for Q5, Q6 = 1.28 W
(0x1B80)
PLPF12 = thermal LPF pole for Q1, Q2 (0x0100 for
M = 128)
PLPF34 = thermal LPF pole for Q3, Q4 (0x0100 for
M = 128)
PLPF56 = thermal LPF pole for Q5, Q6 (0x0010 for
M = 2048)
In the case where the Si3200 is used, the thermal
filtering needs only to be performed only on the total
power reflected in the PSUM RAM location. When the
filter output exceeds the total power threshold, an
interrupt is issued. The PTH12 RAM location is used to
preset the total power threshold for the Si3200, and the
PLPF12 RAM location is used to preset the thermal low
pass filter pole.
Automatic State Change Based on Power Alarm
If any of the following situations occurs, the device will
automatically transition to the OPEN state:
!
!
!
To provide optimal reliability, the device automatically
transitions into the open state until the user changes the
state manually, independent of whether or not the power
alarm interrupt has been masked. The PQ1E–PQ6E
bits of the IRQEN3 register enable the interrupts for
each transistor power alarm and the PQ1S to PQ6S bits
of the IRQVEC3 register are set when a power alarm is
triggered in the respective transistor. When using the
Si3200, the PQ1E bit enables the power alarm interrupt,
and the PQ1S bit is set when a Si3200 power alarm is
triggered.
The thermometer based power alarm in the Si3200
is asserted.
Any of the transistor power alarm thresholds is
exceeded, in the case of the discrete transistor
circuit.
The total power threshold is exceeded, when using
the power calculator method along with the Si3200.