Si3210/Si3211/Si3212
Table 22. Measured Realtime Linefeed Interface Characteristics
Parameter
Measurement
Range
Resolution
Register
Bits
Location*
Loop Voltage Sense (V
– V
)
RING
–94.5 to +94.5 V
1.5 V
LVSP,
Direct Register 78
TIP
LVS[6:0]
Loop Current Sense
–80 to +80 mA
1.27 mA
LCSP,
Direct Register 79
LCS[5:0]
TIP Voltage Sense
RING Voltage Sense
0 to –95.88 V
0 to –95.88 V
0 to –95.88 V
0 to –95.88 V
0 to 81.35 mA
0 to 81.35 mA
0 to 9.59 mA
0 to 9.59 mA
0 to 80.58 mA
0 to 80.58 mA
0.376 V
0.376 V
VTIP[7:0]
Direct Register 80
Direct Register 81
VRING[7:0]
Battery Voltage Sense 1 (V
Battery Voltage Sense 2 (V
)
)
0.376 V
VBATS1[7:0] Direct Register 82
VBATS2[7:0] Direct Register 83
BAT
0.376 V
BAT
Transistor 1 Current Sense
Transistor 2 Current Sense
Transistor 3 Current Sense
Transistor 4 Current Sense
Transistor 5 Current Sense
Transistor 6 Current Sense
0.319 mA
0.319 mA
37.6 µA
37.6 µA
0.316 mA
0.316 mA
IQ1[7:0]
IQ2[7:0]
IQ3[7:0]
IQ4[7:0]
IQ5[7:0]
IQ6[7:0]
Direct Register 84
Direct Register 85
Direct Register 86
Direct Register 87
Direct Register 88
Direct Register 89
*Note: The ProSLIC uses registers that are both directly and indirectly mapped. A “direct” register is one that is mapped
directly.
Power Monitoring and Line Fault Detection
the type of fault condition present on the line.
In addition to reporting voltages and currents, the The value of each thermal low-pass filter pole is set
ProSLIC continuously monitors the power dissipated in according to the equation:
each external bipolar transistor. Realtime output power
4096
23
of any one of the six linefeed transistors can be read by
----------------
thermal LPF register =
800
τ
setting the Power Monitor Pointer (direct Register 76) to
point to the desired transistor and then reading the Line
Power Output Monitor (direct Register 77).
where τ is the thermal time constant of the transistor
package, 4096 is the full range of the 12-bit register, and
800 is the sample rate in hertz. Generally τ = 3 seconds
for SOT223 packages and τ = 0.16 seconds for SOT23,
but check with the manufacturer for the package
thermal constant of a specific device. For example, the
power alarm threshold and low-pass filter values for Q5
and Q6 using a SOT223 package transistor are
computed as follows:
The realtime power measurements are low-pass filtered
and compared to
a maximum power threshold.
Maximum power thresholds and filter time constants are
software programmable and should be set for each
transistor pair based on the characteristics of the
transistors used. Table 23 describes the registers
associated with this function. If the power in any
external transistor exceeds the programmed threshold,
a power alarm event is triggered. The ProSLIC sets the
Power Alarm register bit, generates an interrupt (if
enabled), and automatically enters the Open state (if
AOPN = 1). This feature protects the external
transistors from fault conditions and, combined with the
loop voltage and current monitors, allows diagnosis of
PMAX
1.28
------------------------------
PPT56 =
27
=
27 = 5389 = 150Dh
-----------------
Resolution
0.0304
Thus, indirect Register 34 should be set to 150Dh.
Note: The power monitor resolution for Q3 and Q4 is different
from that of Q1, Q2, Q5, and Q6.
24
Preliminary Rev. 1.11
ETC [ ETC ]
