SI2493-C-FT Silicon Laboratories Inc, SI2493-C-FT Datasheet - Page 159

• Manufacturer Part Number: SI2493-C-FT
• Description: 56 KBPS, V.92 ISOMODEM SYSTEM-SIDE - LEAD-FREE TSSOP 0 TO 7
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-C-FT

• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.29, V.32, V.34, V.90, V.92, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: Parallel
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15-side pad leaving the other end of C1 unconnected.
Next, solder a short jumper wire from the unconnected
side of C1 on the evaluation board to the Si3018/10-
side C1 pad on the prototype system. This connection is
illustrated in Figure 32. Connect the phone line to the
prototype system RJ-11 jack.
Power up and manually reset the evaluation board, then
power up the prototype system. Attempt to make a
connection using the host processor and software, the
evaluation board Si2493/57/34/15/04, and the prototype
system Si3018/10 and associated external components.
If this connection is successful, the problem lies with the
PCB layout, the external components associated with
the Si2493/57/34/15/04 or the Si2493/57/34/15/04
device itself.
If the connection attempt is not successful, the problem
lies with the Si3018/10 and/or associated components.
Proceed to the next section, “Si3018/10 Troubleshooting”.
This diagnosis can be validated by connecting the Host
ISOcap capacitors to the Si3018/10 on the evaluation
board as shown in Figure 33.
Si3018/10 Troubleshooting
Start by measuring the on-hook and off-hook voltages at
the Si3018/10 pins with respect to IGND (pin 15).
Compare these voltages to those in Figure 34. This may
indicate an area of circuitry to investigate further using
the Component Troubleshooting techniques. The
voltages you measure should be close to (although not
exactly the same as) those in the figure.
Connect prototype system ground to EVB ground
Disable RS232 transceiver outputs (check evaluation board data sheet)
Disconnect prototype modem interface
Connect the evaluation board to the target system
Controller
Host
EVB
Transceiver
RS232
UART
Host
Figure 30. Test the Host Interface
Rev. 0.9
Si24xx
Si24xx
If any of the on-hook and off-hook Si3018/10 pin
voltages are grossly different than those in Figure 34
and nothing seems wrong with the external circuitry
after using the Component Troubleshooting techniques,
replace the Si3018/10.
Component Troubleshooting
A digital multimeter is a valuable tool for verifying
resistances across components, diode directions,
transistor polarities and node voltages. During this
phase of troubleshooting, it is very useful to have a
known,
against measurements taken from the prototype
system. The resistance values and voltages listed in
Tables 102, 103, and 104 will generally be sufficient to
troubleshoot all but the most unusual problems.
Start with power off and the phone line disconnected.
Measure the resistance of all Si3018/10 pins with
respect
measurements with the values in Table 102. Next,
measure the resistance across the components listed in
Table 103 and compare the readings to the values listed
in the table. Finally, using the diode checker function on
the multimeter, check the polarities of the transistors
and diodes as described in Table 104. The combination
of these measurements should indicate the faulty
component or connection. If none of the measurements
appears unusual and the prototype modem is not
working, replace the Si3018/10.
good
to
Si3018
Si3018
Prototype System
pin 15
Si2457/34/15URT-EVB
(IGND).
Discretes
Discretes
Compare
to
AN93
compare
To
Phone
Line
these
159