SI3016-F-FS Silicon Laboratories Inc, SI3016-F-FS Datasheet - Page 15

• Manufacturer Part Number: SI3016-F-FS
• Description: IC ISOMODEM LINE-SIDE DAA 16SOIC
• Manufacturer: Silicon Laboratories Inc
• Type: Chipsetr

Specifications of SI3016-F-FS

• Package / Case: 16-SOIC (3.9mm Width)
• Data Format: V.90
• Baud Rates: 56k
• Interface: Serial
• Voltage - Supply: 3.3V, 5V
• Mounting Type: Surface Mount
• Product: Modem Chip
• Supply Current: 0.3 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.5. Parallel Handset Detection
The Si3016 is capable of detecting a parallel handset
going off-hook. When the Si3016 is off-hook, the loop
current can be monitored via the LVCS bits. A significant
drop in loop current can signal a parallel handset going
off-hook. If a parallel handset causes the LVCS bits to
read all 0s, the Drop-Out Detect (DOD) bit may be
checked to verify that a valid line still exists.
When on-hook, the LVCS bits may also be read to
determine the line voltage. Significant drops in line
voltage may also be used to detect a parallel handset.
For the Si3016 to operate in parallel with another
handset, the parallel handset must have a sufficiently
high dc termination to support two off-hook DAAs on the
same line. The OFF bit in Register 16 is designed to
improve parallel handset operation by changing the dc
impedance from 50 Ω to 800 Ω and reducing the DCT
pin voltage.
4.6. Line Voltage/Loop Current Sensing
The Si3016 has the ability to measure both line voltage
and loop current. The five bit LVCS register reports line
voltage measurements when on-hook, loop current
measurements when off-hook, or on-hook line monitor
data depending on the state of the MODE, OH, and
ONHM bits. Using the LVCS bits, the user can
LVCS
BITS
30
25
20
15
10
5
0
Figure 8. Typical Loop Voltage LVCS Transfer Function
0
3 6
9
12
15
18
21
24
27
30
Loop Voltage (V)
33
36 39 42 45 48
Rev. 1.0
51
determine the following:
4.6.1. Line Voltage Measurement
The Si3016 reports the line voltage with the LVCS bits in
Register 19. LVCS has a full scale of 87 V with an LSB
of 2.75 V. The first code (0 → 1) is skewed such that a 0
indicates that the line voltage is < 3 V. The accuracy of
the LVCS bits is ±20%. The user can read these bits
directly through the LVCS register when it is on-hook
and the MODE bit is set to 1. A typical transfer function
is shown in Figure 8.
4.6.2. Loop Current Measurement
When the Si3016 is off-hook, the LVCS bits measure
loop current in 3 mA/bit resolution. These bits enable
the user to detect another phone going off-hook by
monitoring the dc loop current. The line voltage current
sense transfer function is shown in Figure 9 and is
detailed in Table 10.
54
57
When on-hook, detect if a line is connected.
When on-hook, detect if a parallel phone is off-hook.
When off-hook, detect if a parallel phone goes on or
off-hook.
Detect if enough loop current is available to operate.
Detect if there is an overload condition which could
damage the DAA (see overload protection feature).
60
63
66
69
72
75 78 81 84 87
100
Si3016
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