an9955

Operation of the HC55185 Ringing SLIC &
IDT821068 Evaluation Module
TM
Application Note
October 2001
AN9955.1
Author: Don LaFontaine
Functional Description
Verifying Basic Operation
This application note is intended to supplement IDT’s
Evaluation Board User’s Guide. The Users guide describes
the Evaluation Board System and use of its software. The
system includes one IDT821068 evaluation board, one
HC55185 evaluation board and control software
IDT821068.exe. For discussion purposes, the IDT821068
evaluation board will be referred to as the Mother Board and
the HC55185 evaluation board will be referred to as the
Daughter Board.
The operation of the Mother & Daughter Boards can be
verified by performing the following tests:
A good understanding of the material in the Users Guide is a
prerequisite to this application note. For a detailed
engineering analysis of the reference design using the
HC55185 and IDT821068, see application note AN9947.
With this system, the user can configure a channel to
channel conversation and perform various tests on the
system using a Wandel and Golterman (W&G) PCM4.
The IDT821068 Evaluation Board System can be configured
in two modes of operation via JP1, JP2 & JP3 on the mother
board.
• Emulation Mode, Emulation Mode gets its name from the
evaluation board’s ability to emulate a far end callee (or
caller) telephone conversation as a stand alone unit. In
this mode the DC performance of the SLIC (logic state, Tip
& Ring voltage levels, on hook & off hook detection) and
channel to channel conversation is easily evaluated using
the on-board clock circuit of the Mother Board.
Jumper configuration:
JP1 jumper IN (shorting DX/DR)
JP2 jumper IN (providing power to the on board oscillator)
JP3 IN (connecting INTERNAL clock to board)
• Test Mode, Test Mode gets its name from the evaluation
board’s ability to test the performance of the system using
a PCM4. In this mode the AC performance of the half
channel (D/A, A/D, D/D) can be evaluated.
Jumper configuration:
JP1 jumper OUT
JP2 jumper OUT
JP3 IN (connecting EXTERNAL clock to board)
This application note will first evaluate the DC performance
of the system by configuring the Jumpers in the Emulation
Mode. Figure 3 shows the required connection between the
Evaluation Board, PC, PCM4 tester and Power Supplies.
Proper connection should be established before running the
software.
If the user prefers to evaluate the AC performance first, then
along with the proper connections (Figure 3) and jumpers
positioned for the test mode, the user needs to insure the
clock of the PCM4 is connected before running the software.
1
1. Normal Loop Feed Verification
Tip & Ring Voltage Forward Active State, On Hook
Tip & Ring Voltage Forward Active State, Off Hook
Tip & Ring Voltage Reverse Active State, On Hook
Tip & Ring Voltage Reverse Active State, Off Hook
2. Loop Supervisory Detection
On Hook & Off Hook
Tip Open State, Ground Key Test
Forward Loopback State
3. Ringing Verification
4. Programming of Coefficients
5. Emulation of Far End Telephone Conversation
6. Gain Verification
Total System Gain (Digital to Digital)
7. Variable Gain/Frequency
Receive Gain (Digital to Analog)
Transmit Gain (Analog to Digital)
8. Total Distortion
Receive Gain (Digital to Analog)
Transmit Gain (Analog to Digital)
HC55185 Daughter Board
The HC55185EVAL1 evaluation board is optimized to match
a 600Ω and a 200Ω + 680Ω||0.1µF line impedances, have a
Ring Trip Threshold of 76mA, a Switch Hook Threshold of
12mA, Loop Current Limit of 24.6mA and a Transient
Current Limit of 95mA.
The daughter board is a dual channel board that enables
testing between adjacent channels (CH1 to CH2, CH3 to
CH4, CH5 to CH6, and CH7 to CH8). An additional daughter
board can be obtained to enable testing between all
channels. Reference the application note AN9947 for
calculation of external components and programming
coefficients.
Programming of the logic state of the SLIC, loop supervisory
detection, time slot allocation, coefficients, tone/ teletax
signals are all controlled via software using the MPI screen
(Figure 2).
IDT821068 Mother Board
The IDT821068 Mother Board provides a way to evaluate
the operation of IDT’s IDT821068 and Intersil’s HC55185
Ringing SLIC. The programming interface illustrated in this
application note is the Microprocessor Interface (MPI).
Figure 1 shows the IDT821068 mother board component
locations. The location of jumpers JP1, JP2, and JP3 are
highlighted with arrows. JP1 is used to short the DX and DR
1-888-INTERSIL or 321-724-7143
RSLIC18™ is a trademark of Intersil Corporation.
Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2001. All Rights Reserved
|
Application Note 9955
signals from the PCM4 to prevent interference when
Emulation Mode testing is performed. JP2 connects power
to the on-board clock. This enables setup of the software
without having to use the clock from the PCM4. JP3
connects either the on-board clock or the clock from the
PCM4. Proper operation of the software requires this clock
signal.
Discussion
The HC55185 is designed to have its most positive 2-wire
terminal (tip in the forward active state and ring in the
reverse active state) fixed at a set voltage. The most
negative 2-wire terminal voltage is dependent upon the load
across tip and ring and the programmable current limit.
PCM BUS SELECTION
Getting Started
The following steps will configure the Mother Board for
testing in either the Emulation Mode or the Test Mode.
1. Connect IDT821068, HC55185 and PCM4 as shown in
Figure 3. Note: The Daughter Board gets its power from
the Mother Board.
2. Set the General Parameters of the PCM4 as shown in
Table 1 (see Test #6).
3. Once power is applied and the appropriate clock is
supplied to the Mother Board (i.e. internal clock for
Emulation Mode, or PCM4 clock for Test Mode), PRESS
the reset button. The LED will flash and then remain on.
This will synchronize the clock and enable software
control from the PC.
4. Initialize the software by clicking on IDT821068.exe and
select the desired Operating Mode (MPI), COM Port and
SLIC from the Mode and Port selection screen then click
OK.
5. The MPI Mode screen will then appear (Figure 2). All
programming of the channels and monitoring of SLIC
status are performed using this screen.
6. From MPI Software screen, select Channel 1 in the left
shaded area. The top of the right non-shaded area will
show: CHN1: MPI Mode (CHNx for any other x channel)
7. From MPI Software screen, select General in the left
shaded area. Accept defaults or set to your preferences
and click the Write button.
FIGURE 1. IDT821068 MOTHER BOARD COMPONENT LOCATION
8. From MPI Software screen, click on the Auto Detect
Enable box. This will enable the CODEC to detect the
status of the SLIC. Detection will be in the form of the
receiver next to the channel indicator, left shaded area,
being one of the 4 indicators located at the bottom of the
shaded area (Active, Ring, In Use, Power Off). The Auto
Detect Enable box will also activate the I/O Pin Status of
the SLICs DET pin via CD1. A red color signifies a logic
one and green color a logic zero.
9. From MPI Software screen, clicking on the Broadcast
Mode will enable the user to configure multi-channels at
the same time.
10. From MPI Software screen, Select: Active F, BSEL L,
Power On and click the Write button. The SLIC is now
ready to be tested.
Test # 1 Normal Loop Feed Verification
This test verifies the correct tip and ring voltages in both
onhook and offhook forward active and reverse active states.
Loop current and ground key detect are also verified via the
software MPI screen.
2
FIGURE 2. MPI OPERATION GENERAL INTERFACE
Application Note 9955
Detail A Below
Detail B Below
(63)
(61)
(22)
(20)
(21)
FIGURE 3. IDT821068 MOTHER BOARD CONNECTIONS
3
Application Note 9955
Loop supervision is provided by either the switch hook or the
ground key detectors. Loop status is observed by monitoring
the I/O Pin CD1 of the MPI screen. The device may be
operated from either high or low battery for on-hook
transmission, during ringing and low battery for loop feed.
When operating from the high battery, the DC voltages at Tip
and Ring are MTU compliant. The typical Tip voltage is -4V
and the Ring voltage is a function of the battery voltage for
battery voltages less than -60V as shown in Equation 1.
(EQ. 1)
V RING = V BH + 4
Most applications will operate the device from low battery
while off hook. The DC feed characteristic of the device will
drive Tip and Ring towards half battery to regulate the DC
loop current. For light loads, Tip will be near -4V and Ring
will be near VVBL + 4V. Figure 4 shows the DC feed
characteristic.
VTR(OC)
VTR , DC (V)
m = (∆VTR /∆IL) = 11.1kΩ
Measuring Tip and Ring Voltages
1. Configure Hardware and Software as described in section
titled” Getting Started”.
2. Configure Mother Board for Emulation Mode. Verify:
• Jumper JP1 is IN,
• JP2 is IN,
• JP3 is set to Internal BCLK.
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
3. From MPI Software screen, Select: Active F, BSEL H,
Power On and click the Write button.
4. Measure the tip and ring voltages (reference Figure 6)
and compare to those in Table 3 (onhook).
5. Terminate TIP and RING with a 600Ω load via the RJ11
jack.
6. Measure tip and ring voltages with respect to ground and
compare to those in Table 3 (offhook 600Ω).
7. From MPI Software screen, Select: Active R, BSEL H,
Power On and click the Write button.
ILOOP (mA)
8. Disconnect the 600Ω load from across tip and ring.
ILIM
9. Repeat steps 4, 5, 6 and 8.
FIGURE 4. DC FEED CHARACTERISTIC
The point on the y-axis labeled VTR(OC) is the open circuit Tip
to Ring voltage and is defined by the feed battery voltage.
V TR ( OC ) = VBL – 8
TABLE 1. TIP AND RING VOLTAGES
(EQ. 2)
LOGIC STATE
The Ground Key detector operation is verified by configuring
the HC55185 in the tip open state and grounding the ring
pin. Grounding the ring pin results in a current that triggers
an internal detector that pulls the output of DET low causing
I/O Pin CD1 to turn Green.
The Forward Loop Back mode provides test capability for the
device. An internal signal path is enabled allowing for both
DC and AC verification. The internal 600Ω terminating
resistor has a tolerance of ±20%. The device is intended to
operate from only the low battery during this mode.
When the forward loop back mode is initiated internal
switches connect a 600Ω load across the outputs of the Tip
and Ring amplifiers as shown in Figure 5.
TIP
TIP AMP
RL
(Ω )
TIP VOLTAGE RING VOLTAGE
REFERENCEDT REFERENCED
TO GND
O GND
Forward Active
V BH = -48V
VBL = NA
VCC = +5V
Onhook
-3.6 — -4.6
-37.0 — -44.0
Offhook
600Ω
-13.5 — -17.0
-28.0 — -32.0
Reverse Active
VBH = -48V
VBL = NA
VCC = +5V
Onhook
-38.0 — -44
-3.5 — -4.5
Offhook
600Ω
-28.0 — -32.0
-13.5 — -17.0
Test # 2 Loop Supervisory Detection
Verification of Switch Hook Detect
If previous test was Test #1, skip to step 3.
1. Configure Hardware and Software as described in section
titled” Getting Started”.
2. Configure Mother Board for Emulation Mode. Verify:
• Jumper JP1 is IN,
600Ω
HC55185
• JP2 is IN,
• JP3 is set to Internal BCLK.
RING
RING AMP
FIGURE 5. FORWARD LOOP BACK INTERNAL TERMINATION
When the internal signal path is provided, DC current will
flow from Tip to Ring. The DC current will force DET low
causing I/O Pin CD1 to turn Green.
4
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
Application Note 9955
MEASURE TIP
VOLTAGE HERE
MEASURE RING
VOLTAGE HERE
MEASURE TIP
VOLTAGE HERE
MEASURE RING
VOLTAGE HERE
FIGURE 6. DAUGHTER BOARD LAYOUT
3. With the SLIC in either the forward active state (Active F)
or reverse active state (Active R), the phone icon (left
shaded area of the MPI screen) indicates In Use and the
I/O Pin CD1 turns Green when tip and ring are terminated
with 600Ω and Active and Red respectively when tip and
ring are an open circuit.
Verification of Ground Key Detect
1. From MPI Software screen, Select: Tip Open, BSEL H,
Power On and click the Write button.
2. The phone icon (left shaded area of the MPI screen)
indicates Active and the I/O Pin CD1 is Red.
3. Grounding the ring terminal will verify Ground Key Detect
when the phone icon (left shaded area of the MPI screen)
indicates In Use and the I/O Pin CD1 turns Green.
Verification of Forward Loopback
1. From MPI Software screen, Select: Loop, BSEL L, Power
On and click the Write button.
2. Verification of Forward Loopback operation is when the
phone icon (left shaded area of the MPI screen) indicates
In Use and the I/O Pin CD1 is Green.
ring trip. The device is designed to operate from the high
battery during this mode.
Architecture
The device provides linear amplification to the signal applied
to the ringing input, VRS . The differential ringing gain of the
device is 80V/V. The circuit model for the ringing path is
shown in Figure 6.
The voltage gain from the VRS input to the Tip output is
40V/V. The resistor ratio provides a gain of 8 and the current
mirror provides a gain of 5. The voltage gain from the VRS
input to the Ring output is -40V/V. The equations for the Tip
and Ring outputs during ringing are given in Equations 3
and 4.
V BH
V T = ----------- + ( 40 × VRS )
2
(EQ. 3)
VBH
V R = ----------- – ( 40 × VRS )
2
(EQ. 4)
R
Test # 3 Ringing Verification
This test will demonstrate the ability of the IDT821068 to ring
a phone through the HC55185. A telephone is the only
additional hardware required to complete this test.
20
TIP
+
5:1
+
RING
The HC55185 provides linear amplification to support a
variety of ringing waveforms. A programmable ring trip
function provides loop supervision and auto disconnect upon
5
-
+
-
20
Discussion
R/8
-
600K
+ VBH
2
R
FIGURE 7. LINEAR RINGING MODEL
VRS
Application Note 9955
When the input signal at VRS is zero, the Tip and Ring
amplifier outputs are centered at half battery. The device
provides auto centering for easy implementation of
sinusoidal ringing waveforms. Both AC and DC control of the
Tip and Ring outputs are available during ringing. This
feature allows for DC offsets as part of the ringing waveform.
Ringing Input
The ringing input, VRS , is a high impedance input. The high
impedance allows the use of low value capacitors for AC
coupling the ring signal. The VRS input is enabled only
during the ringing mode, therefore a free running oscillator
may be connected to VRS at all times.
When operating from a battery of -100V, each amplifier, Tip
and Ring, will swing a maximum of 95VP-P . Hence, the
maximum signal swing at VRS to achieve full scale ringing is
approximately 2.4VP-P . The low signal levels are compatible
with the output voltage range of the CODEC. The digital
nature of the CODEC ideally suits it for the function of
programmable ringing generator.
Ringing the Phone
If previous test was either Test #1 or #2, skip to step 3.
Test # 4 Programming of Coefficients
Using the DSP coefficients provided by IDT, the overall
performance of the system will pass ITU-T requirements.
When the COF RAM button is selected from the MPI
Operation General Interface screen, the COF RAM
Operation screen will appear (Figure 7). From this screen,
the user can load the coefficients for the current channel.
For IDT to calculate IDT821068 DSP coefficient, customers
should provide the following information about their
subscriber line card:
• Accurate SLIC PSPICE model. It can be provided in .lib
file or PSPICE schematic file.
• System Impedance
• Gain (Transmit path and Receive path)
IDT will then provide the user with 8 files, one for each
channel. An example of a file name is: HC55185_600_1.
The first portion of the file name is the SLIC being used
(HC55185). The second portion of the file name is the line
impedance the coefficients are matching (600Ω) and the last
portion is the channel (1).
1. Configure Hardware and Software as described in section
titled” Getting Started”.
2. Configure Mother Board for Emulation Mode. Verify:
• Jumper JP1 is IN,
• JP2 is IN,
• JP3 is set to Internal BCLK.
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
3. From MPI Software screen, Select: CH 1, Active F,
BSEL H, Power On and click the Write button.
4. From MPI Software screen, Select: Tone/Teletax. The
Dual Tone and Teletax Setting screen will appear. Under
Dual Tone Setting select:
Frequency: High = 20, Low = 0
High Tone = Enable
Low Tone = Disable
Inversion = No Inversion
Tone Gain = 63.
Then click the Write button.
5. Connect a phone to Channel 1 using the RJ11 jack on the
Daughter Board
6. From MPI Software screen, Select Ring and the phone
will start to ring. Cadencing of the ring signal is
accomplished by switching between Ring and Active F
(or Active R). Note: the command to the SLIC is
immediate, you don’t have to press Write for the
command to be invoked.
7. When the test is completed, you need to Disable the High
Tone. This will prevent the tone from interfering with
subsequent tests.
6
FIGURE 8. COEFFICIENT RAM OPERATION SCREEN
Loading Coefficients
If previous test was Test #1, #2 or #3, skip to step 3.
1. Configure Hardware and Software as described in section
titled” Getting Started”.
2. Configure Mother Board for Emulation Mode. Verify:
• Jumper JP1 is IN,
• JP2 is IN,
• JP3 is set to Internal BCLK.
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
Application Note 9955
3. From MPI Software screen, Select the desired Channel
by clicking on the channel button in the left shaded area
4. From MPI Software screen, Select COF RAM. The
Coefficient Ram Operation screen will appear (Figure 7).
Down loading Coefficients from a File:
• Click on Load and the desk top window opens.
Navigate to where the file is stored and select the
coefficients for the channel being programmed.
Opening the file will automatically load the coefficients
into COF RAM screen. Another window will appear to
inform you that the file successfully loaded.
6. For communications between Channel 1 and Channel 2,
one possible configuration is:
Set Channel 1
Set Channel 1
Set Channel 2
Set Channel 2
Transmit = 000, DX1
Receive = 001,DR1
Transmit = 001,DX1
Receive = 000, DR1
7. Set the transmit and receive paths as shown in step 6 and
click the Write button.
8. Connect Phones to the RJ11 jacks of both Channels 1 and
Channel 2. Communication between Channels 1 and 2 is
now possible.
• Click OK. Exit the screen by click the Close button
(don’t write files from this screen). This will return you
to the MPI Software screen. Click Write from this
screen.
5. Repeat steps 3 and 4 to load the coefficients for the other
channels.
Test # 5 Emulation of Phone Conversation
This test will demonstrate an end to end phone conversation
between Channel 1 and Channel 2. Setting up an end to end
phone conversation is accomplished with the Timeslot and
PCM Highway Assignment screen (Figure 8). The
IDT821068 has two PCM buses (DX1/DR1 and DX2/DR2)
and can be configured up to 128 time slots on each PCM
bus. The user can select any time slot and any PCM bus for
a Channels transmit and receive. If the time slot assigned to
the receive path of Channel X is the same one assigned to
the transmit path of Channel Y, and the time slot assigned to
the transmit path of Channel X is the same one assigned to
the receive path of Channel Y, then Channel X and Channel
Y can communicate with each other.
Assigning Timeslots
If previous test was Test #1, #2, #3 or #4, skip to step 3.
1. Configure Hardware and Software as described in section
titled” Getting Started”
2. Configure Mother Board for Emulation Mode. Verify:
• Jumper JP1 is IN,
• JP2 is IN,
• JP3 is set to Internal BCLK.
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
3. From MPI Software screen, Select Dual Tone Setting and
verify that both the High Tone and Low Tone are
Disabled. This will prevent the high or low tone signals
from interfering with the Channel to Channel
communication.
4. From MPI Software screen, Select Timeslot. The Timeslot
and PCM Highway Assignment screen will appear
(Figure 8).
5. Verify the jumpers at the top of the Mother Board are in the
DX1 and DR1 positions (reference Figure 1).
7
FIGURE 9. TIMESLOT & PCM HIGHWAY ASSIGNMENT SCREEN
Test # 6 Gain Verification
This test will verify the gains through the IDT821068 and the
HC55185 are operating properly. The test will show, with the
proper coefficients loaded into the CODEC, the Digital to
Analog gain across both the CODEC and the SLIC is equal
to -1.0 (0.0dB), and the Analog to Digital gain across both
the SLIC and the CODEC is also equal to 1.0 (odB). Both
D/A and A/D gains will be verified by performing a Digital to
Digital gain using the PCM4.
Figure 9 shows the reference design of the HC55185 and
the IDT821068 with a 600Ω load impedance and transmit
and receive gains of 0dB. Reference An9947 for a detailed
engineering analysis of the reference design.
Total System Gain (D/D)
If previous test was Test #1, #2, #3, #4 or #5, skip to step 2.
1. Configure Hardware and Software as described in section
titled” Getting Started”
2. Prerequisite for this test is that test #4 “Programming of
Coefficients” be completed using the 600Ω coefficients,
system gains: (A/D = 0dB, D/A = 0dB) and CODEC
analog gains: (A/D = +6dB, D/A = 0dB) Table 1 of
application note AN9947.
3. Terminate tip and ring with a 600Ω load via the RJ11 jack.
Application Note 9955
SYSTEM REQUIREMENTS:
IMPEDANCE: 600Ω
TRANSMIT GAIN (A/D): 0dB
RECEIVE GAIN (D/A): 0dB
0dBm0(600Ω)
0.7745VRMS
0dBm0(600Ω)
0dBm0 (600Ω)
0.7745VRMS
0.7745VRMS
INTERSIL
HC55185 (1 of 8)
RP
49Ω
VRX
TIP
+
V2W
-
+
ZL
VOUT1
ANALOG
Gain
0DB
DIGITAL
GAIN
0dB
VIN1
ANALOG
GAIN
6dB
DIGITAL
GAIN
+1.6dB
0.47µf
VTR
-
EG
RING
RECEIVE PATH
DSP
CORE
.
.
.
CTX
ZO
VTX
RS 0.47µf
66.5kΩ
ZO = ZL - 2RP
PCM
BUS
TRANSMIT PATH
CHANNEL 2
RP
49Ω
ZTR
IDT821068
CHANNEL 1
CRX
DR1/DD
PCM/GCI
INTERFACE
DX1/DU
CHANNEL 8
-IN
0dBm0(600Ω)
CFB
0.7745VRMS
VFB
-7.5769dBm0(600Ω)
4.7µf
0dBm0(600Ω)
0.7745VRMS
0.3239VRMS
G2-4
OTE: Reference Table 1 AN9947 for coefficients.
FIGURE 10. REFERENCE DESIGN OF THE HC55185 AND THE IDT821068 WITH A 600Ω LOAD IMPEDANCE
TABLE 2. PCM4 GEN. PARAMETERS SETTINGS (Continued)
4. Configure Mother Board for TEST Mode. Verify:
• Jumper JP1 is OUT,
• JP2 is OUT,
• JP3 is set to External BCLK.
Note: Once the software is initiated (section “Getting
Started”), the user can switch between Emulation and
Test modes and still maintain software control.
5. Set the General Parameters of the PCM4 as shown in
Table 1.
6. Set the PCM4 transmit and receive channels to
channel 0. This will enable the PCM4 to receive and
transmit data to the Channel 1 PCM time slot. To test
channel 2 of the Mother Board, set the PCM4 to channel
1. Continue this pattern for remaining channels.
7. From MPI Software screen, set the A/D (Transmit)
Gain = +6dB and the D/A (Receive) Gain = 0dB.
8. Configure the PCM4 for the MODE A 11 test. Set PCM4
to D-D, SWP/S (single sweep). Press start to test
network.
Verification
TABLE 2. PCM4 GEN. PARAMETERS SETTINGS
SETTING
(1) Digital Configuration:
General configuration
TX/RX 2M/2Mbits/s
selected
OPEN/AUX.SIGN.
Digital Loop (A - A)
(2) Frame Selection:
TX frame type
RX frame type
CRC-4 Multiframe
All 32 TS teleph
All 32 TS teleph
Off
8
PARM
11
23
14
24
31
SETTING
PARM
(3) Digital TX Interface:
Line Code
Output Impedance
Clock
NRZ
75 ohms unbalanced
Int. 2048 kHz
13
22
31
(4) Digital RX I nterface:
Line Code
Input Impedance
NRZ
> 3K Ohms
13
22
Reset to standard values
ALL CHAN.
11
22
Off
11
(5) Digital Words in TX
Frame:
Frame Words
Send Signal
(6) TX Error Insertion
(7) PCM Coding:
TX Encoding Law
Must match switch S7-6 on 11
IDT821068 EVM. Default
setting on EVM is A-law
Must match encoding law
RX Encoding Law
(8) Scanner Parameter:
VF-Input no.
VF-Output no.
Compare results to the Figure11
GENERAL PARAMETER
GENERAL PARAMETER
(9) Special Parameter:
Level Display
Two wire Term.
Digital Channel no.
21
1
1
11
21
dBm0
Infinite
Time Slot
Mark and cont.
11
13
16
22
23
27
33
35
Tolerance mask set 2
Clock display
OFF
Mark and cont.
OFF
Application Note 9955
channel 2 of the Mother Board, set the PCM4 to channel
1. Continue this pattern for remaining channels.
6. From MPI Software screen, set the A/D (Transmit)
Gain = +6dB and the D/A 9Receive Gain) = 0dB.
7. Remove the 600Ω load from across tip and ring.
8. From MPI Software screen, Select Loop
9. Configure the PCM4 for the MODE A 33 test. Set PCM4
to D-A, SWP/S (single sweep). Press start to test
network.
Verification
Compare results to the Figure 12.
FIGURE 11. TOTAL SYSTEM GAIN (D/D)
Test # 7 Variable Gain / Frequency
This test will configure the HC55185 in the loopback mode
and evaluate the IDT821068 and the HC55185’s AC
performance across frequency.
Discussion
Most of the SLICs in the HC55185 family feature 2-Wire
loopback testing. During the 2-wire loopback test, a 600Ω
internal resistor is switched across the tip and ring terminals
of the SLIC. This allows the DET function and the 4-wire to
4-wire AC transmission, right up to the subscriber loop, to be
tested.
Variable Gain / Frequency (D/A) Test #7a
If previous test was Test #1, #2, #3, #4, or #5, skip to step 2.
If previous test was Test # 6 skip to step 7.
1. Configure Hardware and Software as described in section
titled” Getting Started”
FIGURE 12. (D/A) VARIABLE GAIN vs. FREQUENCY
Variable Gain / Frequency (A/D) Test #7b
1. Configure the PCM4 for the MODE A 33 test. Set PCM4
to A-D, SWP/S (single sweep). Press start to test
network.
Verification
Compare results to the Figure 13.
2. Prerequisite for this test is that test #4 “Programming of
Coefficients” be completed using the 600Ω coefficients,
system gains: (A/D = 0dB, D/A = 0dB) and CODEC
analog gains: (A/D = +6dB, D/A = 0dB) Table 1 of
application note AN9947.
3. Configure Mother Board for TEST Mode. Verify:
• Jumper JP1 is OUT,
• JP2 is OUT,
• JP3 is set to External BCLK.
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
4. Set the General Parameters of the PCM4 as shown in
Table 1.
5. Set the PCM4 transmit and receive channels to
channel 0. This will enable the PCM4 to receive and
transmit data to the Channel 1 PCM time slot. To test
9
FIGURE 13. (A/D) VARIABLE GAIN vs. FREQUENCY
Application Note 9955
Test # 8 Total Distortion
Verification
This test will configure the HC55185 in the loopback mode
and evaluate the IDT821068 and the HC55185’s Total
Distortion.
Compare results to the Figure 14.
Total Distortion (D/A) Test #8a
If previous test was Test # 1, #2, #3, #4, or #5, skip to step 2.
If previous test was Test # 6 skip to step 7.
If previous test was Test #7a/b skip to step 9.
1. Configure Hardware and Software as described in section
titled” Getting Started”
2. Prerequisite for this test is that test #4 “Programming of
Coefficients” be completed using the 600Ω coefficients,
system gains: (A/D = 0dB, D/A = 0dB) and CODEC
analog gains: (A/D = +6dB, D/A = 0dB) Table 1 of
application note AN9947.
3. Configure Mother Board for TEST Mode. Verify:
• Jumper JP1 is OUT,
• JP2 is OUT,
• JP3 is set to External BCLK.
NOTE: Once the software is initiated (section “Getting Started”), the
user can switch between Emulation and Test modes and still
maintain software control.
4. Set the General Parameters of the PCM4 as shown in
Table 1.
5. Set the PCM4 transmit and receive channels to
channel 0. This will enable the PCM4 to receive and
transmit data to the Channel 1 PCM time slot. To test
channel 2 of the Mother Board, set the PCM4 to channel
1. Continue this pattern for remaining channels.
FIGURE 14. (D/A) TOTAL DISTORTION
Total Distortion (A/D) Test #8b
1. Configure the PCM4 for the MODE A 55 test. Set PCM4
to A-D, SWP/S (single sweep). Press start to test
network.
Verification
Compare results to the Figure 15.
6. From MPI Software screen, set the A/D (Transmit)
Gain = +6dB and the D/A 9Receive Gain) = 0dB.
7. Remove the 600Ω load from across tip and ring.
8. From MPI Software screen, Select Loop
9. Configure the PCM4 for the MODE A 55 test. Set PCM4
to D-A, SWP/S (single sweep). Press start to test
network.
FIGURE 15. (A/D) TOTAL DISTORTION
10
Application Note 9955
Daughter Board Schematic
VBH
J1
VCC
J1
B18
B16
J1
J1
J1
B2
B15
B21
GND
C7
0.1uF
4
Q1
MUR120
D2
28
C1
0.47uF
TP1
R5
Q2
VBL
F1250T
F2
C9
SW+
25
23.7K R2
27
R6
49.9K
71.5K
C3
24
4.7uF
17
26
VCC
C4
0.47UF
18
VRS
U1
R4
16
HC55185
-IN
SWC
RTD
EO
RD
F0
ILIM
F1
F2
CDC
BSEL
POL
DET
TL
ALM
BGND
0.47uF
R7
22
C8
7
4.7uF
B1
J1 VTX
C12
R8
66.5k
21
J1 VRX
C10
0.47uF
SW-
18.7K
B3
20
VTX
VFB
R1
0.47uF
19
VRX
TIP
5
6
TP2
VCC
RING
0.1uF
3
49.9
0.47uF
C2
0
SWC
S1
C11 OPEN
11
B8
10
B9
9
B10
8
B11
15
B5
12
B6
13
B7
J1 EO
J1 FO
J1 F1
J1 F2
J1 BSEL
J1 DET
J1 ALM
AGND
2
14
CHANNEL A
J1
J1
J1
B2
B15
B21
VBH
J1
VCC
J1
B18
B16
GND
0.1uF
C19
Q3
D4
TIP
RING
23
VBH
R11
MUR120
MUR120
D5
Q4
F1250T
F4
1
49.9
28
C13
0.47uF
TP1
R13
TP2
49.9
C 14
0.47uF
VRX
27
R14 49.9K
26
C 15
VCC
C 16 4.7uF
R12
18.7K
24
17
16
19
RING
VRS
U2
SW-
-IN
RTD
EO
RD
F0
ILIM
F1
F2
CDC
BSEL
POL
DET
TL
ALM
2
18
B22
0.47uF
20
22
21
7
C 20
4.7uF
R15
R16
66.5k
0
J1 VTX
SWC
S2
C23 OPEN
11
B27
B28
9
B29
8
B30
15
B24
12
B25
13
B26
AGND
14
CHANNEL B
11
B20
C24
10
FIGURE 16. HC55185 DEMO DAUGHTER BOARD SCHEMATIC
J1 VRX
C22
0.47uF
VTX
HC55185
BGND
0.1uF
0.47uF
C 21
VFB
25
C18
VBL
TIP
SW+
23.7K R10
0.47UF
VCC
5
6
C17
3
SWC
R9
71.5K
B17
0.1uF
4
F3
F1250T
VBL
J1
D6
RJ-11
B1100CC
RING
MUR120
1
49.9
B1100CC
D1
TIP
23
VBH
R3
C5 C6
0.1uF
D3
RJ-11
F1
F1250T
VBL
J1
B17
J1 EO
J1 FO
J1 F1
J1 F2
J1 BSEL
J1 DET
J1 ALM
Application Note 9955
TABLE 3. DAUGHTER BOARD COMPONENT LIST
COMPONENT
VALUE
TOLERANCE
RATING
U1,U2 - SLIC
HC55185
N/A
N/A
Q1,Q2,Q3,Q4 BATTRIX
B1100CC
N/A
N/A
R3, R5, R11, R13 (Line feed resistors)
49.9Ω
Matched 1%
2.0W
R1,R9
23.7kΩ
1%
1/16W
R2,R10
49.9KΩ
1%
1/16W
R4,R12
18.7kΩ
1%
1/16W
R6,R14
71.5kΩ
1%
1/16W
R7R15
66.5kΩ
1%
1/16W
R8,R16
0Ω
1%
1/16W
C2 ,C4,C9,C10,C12,C14,C16,C21,C22,C24
0.47µF
20%
50V
C1,C13
0.47µF
20%
200V
C3,C8,C15,C20
4.7µF
10%
50V
C5,C6,C17,C18
0.1µF
20%
50V
C7,C19
0.1µF
20%
200V
C11,C23
OPEN
-
-
-
-
DET and ALM LEDs
Red
D1,D2,D4,D5
MUR120
F1,F2,F3,F4
F1250T
D3,D6, Recommended if the VBL supply is not derived from the
V BH supply.
1N4004
Design Parameters: Ring Trip Threshold = 76mApeak, Switch Hook Threshold = 12mA, Loop Current Limit = 24.6mA,
Transient current limit = 95mA.
All Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
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