EXAR XRT5794ES

XRT5794ES
Evaluation
System
balanced 120W operation are one quarter inch, 3-circuit
audio type jacks. Equipment connections should be made
with shielded twisted pair patch cords. The signal applied
to any inputs must be a CCITT G.703 compliant pulse that
may be attenuated by a twisted-pair cable. The XR-T5794
exceeds G.703 maximum cable loss of requirement of 6.0
dB at 1.024 MHz.
GENERAL DESCRIPTION
The XR-T5794 demo board is a 4.75” x 9.75”
double-sided circuit card that provides the support
circuitry necessary for a comprhensive evaluation of the
XR-T5794 CMOS Quad E1 Line Interface IC. three
board-mounted DIP switches allow complete testing of all
loop back, monitor, and transmitter power-down features.
The demo board is normally supplied configured for 120W
balanced E1 operation. However, the information
contianed in this manual enables the user to modify the
hardware for E1 unbalanced 75W cable service, or T1
balanced 100W use.
Similarly, transmitter outputs are labeleds TXOUT1
through TXOUT4 for the four channels. The monitor
channel output is labeled MONOUT. Connector types
and connection methods are identical to those specified
above for the recieve side. The transmitter output, when
terminated by a 120W resistor, is a pulse meeting the
G.703 template requirements. During demo board
evaluation, all ransmitters, including the monitor channel,
that are not powered down should be connected to either
a properly terminated cable, a piece of test equipment
contianing a termination, or a 120W load resistor.
BOARD OPERATION
Figures 1, 2 and Table 2 are the board component layout,
circuit diagram, and parts list respectively. The Demo
Board uses the same pin function and signal names as
the XR-T5794 data sheet. This user’s manual is designed
to be used in conjuction with the XR-T5794 data sheet.
The following description if for a demo board set up for
balanced 120 W E1 use. It also applies to the other modes
of operation if the appropriate impedence, cable type, and
signal source changes are made.
Equipment-Side Signal Connections
For
convenience, access
to
the
logic-level
equipment-side signals is provided by two groups of turret
terminals and also by two ribbon cable connectors. The
terminals are convient for simple tests while the ribbon
cable connectors reduce the amount of wiring necessary
to connect the entire equipment side of the demo board to
customer equipment.
Power Requirements
Power connections are made to banana jacks located in
the upper left hand corner of the board. Power supply
requirements are:
Header P1 and a group of terminals that provide channel
1 and 2 I/O are located below the XR-T5794. For
channels 3 and 4, P2 and a second group of pins are
located above the XR-T5794. P1 and P2 are dual-row 26
pin headers with only the odd-nimbered pins used to carry
signals. Even-numbered pins are grounded to minimize
ribbon cable crosstalk. Pin 13 is also grounded to provide
isolation between the transmit and receive directions.
VDD = +5.0 V ±5% at 850 mA maximum
VSS = - 5.0 V ±5% at 850 mA minimum
Line-Side Signals
Receiver signal inputs are labeled RXIN1 through RXIN4
for the four channels. The connectors supplied for
Rev. 2.00
5
XRT5794ES
For P1 and P2 respectively, Table 1 and 2 presented below give the header pin, signal symbol, the corresponding
XR-T5794 pin, and a brief description of the signal present.
P1 Pin
Symbol
T5794 Pin
Signal Description
1
LOS1
39
Channel 1 - Receive Loss of Signal Output
3
LOS2
40
Channel 2 - Receive Loss of Signal Output
5
RXNEG1
45
Channel 1 - Receive Negative Rail Output
7
RXPOS1
46
Channel 1 - Receive Positive Rail Output
9
RXNEG2
47
Channel 2 - Receive Negative Rail Output
11
RXPOS2
48
Channel 2 - Receive Positive Rail Output
15
TXNEG1
53
Channel 1 - Transmit Negative Rail Input
17
TXPOS1
54
Channel 1 - Transmit Positive Rail Input
19
TXCLK1
55
Channel 1 - Transmit Clock Input
21
TXNEG2
56
Channel 2 - Transmit Negative Rail Input
23
TXPOS2
57
Channel 2 - Transmit Positive Rail Input
25
TXCLK2
58
Channel 2 - Trnasmit Clock Input
Table 1. Header P1 - Channel 1 and 2 Equipment Side I/O Connections
P2 Pin
Symbol
T5794 Pin
Signal Description
1
TXCLK4
12
Channel 4 - Transmit Clock Input
3
TXPOS4
13
Channel 4 - Transmit Positive Rail Input
5
TXNEG4
14
Channel 4 - Transmit Negative Rail Input
7
TXCLK3
15
Channel 3 - Transmit Clock Input
9
TXPOS3
16
Channel 3 - Transmit Positive Rail Input
11
TXNEG3
17
Channel 3 - Transmit Negative Rail Input
15
RXPOS3
22
Channel 3 - Receive Positive rail Output
17
RXNEG3
23
Channel 3 - Recevie Negative Rail Output
19
RXPOS$
24
Channel 4 - Receive Positive Rail Output
21
RXNEG4
25
Channel 4 - Receive Negative Rail Output
23
LOS4
30
Channel 4 - Receive Loss of Signal Output
25
LOS3
31
Channel 3 - Receive Loss of Signal Outpu
Table 2. Header P2 - Channel 3 and 4 Equipment Side I/O Connections
Rev. 2.00
6
XRT5794ES
tranmitter output. The signal applied to a TXPOS input
must be wider that the positive half cycle of the
corresponding TXCLK, and must also meet the set-up
and hold time specified in the XR-T5794 datasheet. When
these conditions are met, the pulse width at the
transmitter output TXOUT is determined by the positive
going half-cycle of TXCLK .
Equipment-Side Signal Characteristics
All equipment-side connections at P1 and P2 are TTL
logic-level compatible for the inputs and outputs. Specific
signal types present at these pins are as follows.
LOS1 Through LOS4
These pins are the loss signal outputs (LOS) for the for
receive channels. A LOS output will go to a logic 1 state
when the input applied to the corresponding receiver is
less that the LOS threshold voltage.
TXNEG1 Through TXNEG4
These pins are the negative rail input for the dual-rail
transmit data for the four transmit channels. A
positive-going pulse at a TXNEG input will produce a
negative bipolar output pulse at the corresponding
transmitter output. The pulse width conditions described
above for the TXPOS input also apply to TXNEG.
RXPOS1 Through RXPOS4
The signal present at these pins is the positive half of the
dual-rail receive data. A positive bipolar input pulse at a
receiver input will produce a positive-going pulse at the
corresponding RXPOS output. Data pulse width at an
RXPOS output is approximately equal to the width of the
pulse applied to the reciever input at its 50% amplitude
point.
Operation Without TXCLK
Operation without TXCLK is possible if this pin is
connected to either DGND or DVDD. Transmit output
pulse width in this mode of operation is determined by the
widths of the pulsed applied to the TXPOS and TXNEG
inputs. Therefore, the data applied to these inputs must
be one-half width return-to-zero (RZ) pulses in order to
produce a normal width bipolar transmit output pulse.
RXNEG1 Through RXNEG4
The signal present at these pins is the negative half of the
dual-rail receive data. A negative bipolar input pulse at a
receiver input will produce a positive-going pulse at the
corresponding RXNEG output. Data pulse width is the
same as described above for the RXPOS output.
DIP Switch Settings
TXCLK1 Through TXCLK4
On the demo board, the logic levels presented at all
control-type XR-T5794 input pins may be set with DIP
switches. The following circuit is used to switch logic
levels. Each IC input that is to be programmed has a 10 K
W pull-up resistor connected to VDD. A SPAT DIP switch
section is also connected between this input and ground.
Therefore, when the switch lever is in the “ON” position as
marked on the switch body, the IC input is at a “Logic 0”
level. For convenience, a small “1” and “0” that indicate IC
pin logic level to switch position correspondence is
printed on the borad at the top end of each DIP switch.
These pins are the transmit clock inputs of four transmit
channels. For a specific channel, TXCLK is a 2.048 MHz
50% duty cycle square wave that is synchronized with the
data to be transmitted over that channel.
TXPOS1 Through TXPOS4
These pins are the positive rail inputs for the dual-rail
transmit data for the four tranmit channels. A
positive-going pulse at a TXPOS input will produce a
positive bipolar outout pulse at the corresponding
Rev. 2.00
7
XRT5794ES
Tables 3, 4 and 5, which are given below, list the switch position, XR-T5794 pin controlled, signal symbol, and
function of the three demo board DIP switches.
Switch Position
IC Pin
Symbol
Switch Setting
1
33
MSEL0
Off
MSEL0 = Logic 1
On
MSEL0 = Logic 0
Off
MSEL1 = Logic 1
On
MSEL1 = Logic 0
On
MSEL2 = Logic 1
Off
MSEL2 = Logic 0
2
3
34
37
MSEL1
MSEL2
Function
4
(Not Used)
Table 3. Dip Switch S1 Functions
Switch Position
IC Pin
Symbol
Switch Setting
1
61
TXEN2
Off
Transmitter 2 Output Enabled
On
Transmitter 2 Output High Impedence
Off
Transmitter 1 Output Enabled
On
Transmitter 1 Output High Impedance
Off
120 W Mode Selected
On
75 W Mode Selected
Off
Channel 2 Loop Mode Enabled
On
Channel 2 Normal Operation
Off
Channel 1 Loop Mode Enabled
On
Channel 1 Normal Operation
Off
E1 Mode Selected
On
T1 Mode Selected
Off
Channel 2 Remote Loop Back Mode
Selected
On
Channel 2 Local Loop back Mode Selected
Off
Channel 1 remote Loopback Mode
Selected
On
Channel 1 Local Loop Back Mode
Selected
2
3
4
5
6
7
8
62
60
52
51
50
42
41
TXEN1
ZSEL
LPEN2
LPEN1
E1/T1B
LPMOD2
LPMOD1
Function
Table 4. Dip Switch S2 Functions
Rev. 2.00
8
XRT5794ES
Switch Position
IC Pin
Symbol
Switch Setting
1
28
LPMOD3
Off
Channel 3 Remote Loop Back Mode
Selected
On
Channel 3 Local Loop Back Mode
Selected
Off
Channel 4 Remote Loop Back Mode
Selected
On
Channel 4 Remote Loop Back Mode
Selected
Off
Channel 3 Loop Mode Enabled
On
Channel 3 Normal Operation
Off
Channel 4 Loop Made Enabled
On
Channel 4 Normal Operation
Off
Monitor Output Enabled
On
Monitor Output High Impedance
Off
Transmitter 3 Output Enabled
On
Transmitter 3 Output High Impedance
Off
Transmitter 4 Output Enabled
On
Transmitter 4 Output High Impedance
2
27
LPMOD4
Function
3
(Not Used)
4
19
LPEN3
5
18
LPEN4
6
10
MONEN
7
8
9
8
TXEN3
TXEN4
Table 5. Dip Switch S3 Functions
HARDWARE CONFIGURATION CHANGES
the nine clip-on jumpers so that they now connect the top
two pins on the 3-pin headers labeled E1 through E9.
This section describes hardware changes necessary for
different modes of operation. It assumes that the demo
board is initially configured for 120W balanced E1 service.
Balanced or unbalanced cable operation is chosen by a
clip-on jumper for each channel and by the installation the
appropriate types of input and output connectors. T1/E1
rate selection is done by one DIP switch section.
100/120W impedance selection for balanced operation
involoves a resistor change.
75W Unbalanced E1 Operation
Replace the 3-circuit audio type jacks used on the
line-side inputs and outputs with BNC connectors (9
total). Wire the center pin of each BNC connector to the
adjacent circuit borad pad labeled “75”.
100W Balanced T1 Operation
Replace 120W resistor R2, R4, R6 and R8, with 100W
parts.
Replace 68W resistors R10, R12, R14, R16 and R18, with
62W parts.
With the demo board oriented so that the power
connections are in the upper left hand corner, reposition
Rev. 2.00
9
XRT5794ES
Qty.
Reference
4
T1,2,3,4
5
Description
Supplier
Input Transforner, 1:1 Ratio
Pulse Eng. PE-65834
T5,6,7,8,9
Output Transformer, 1:1.266 Ratio
Pulse Eng. PE-65839
4
R1,3,5,7
75W, 1/4W, 1% Metal Film Resistor
4
R2,4,6,8
121W, 1/4W, 1% Metal Film Resistor
10
R9, 10, 11,12,13, 14, 15,
16, 17, 18
68.1W, 1/4W, 1% Metal Film Resistor
1
R19
10 K, 2%, 5 Resistor, Thick-film Network
2
R20, 21
10 K, 2%, 9 Resistor, Thick-film Network
2
C1, 2
15
C3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17
1
S1
4-Position DIP Switch
2
S2, 3
8-Position DIP Switch
CTS
68 Pin PLCC Socket
Amp
1
22mF, 16 V, Electrolytic, Axial LEad, 5mm Dia., 2mm
Spacing
0.1 mF, 63 V, Z5U
Dielectric, Axial lead, 0.1” Spacing, Panasonic
CTS
2
P1, P2
26 Pin Dual-Row Header, Gold Pins
2
P1, P2
26 Pin Ribbon Connector For Above
9
E1, 2, 3, 4, 5, 6, 7, 8, 9
9
(Select option on E1
through E9)
9
Line-Side signal connections
3 Pin Single-Row Header, Gold
Shorting Jumper For Above Header
3-Conductor 1/4” Audio Jack, for 3/8” Hole (Connector for
Balanced Line)
3
Banana Jacks, red, Blue, Black
26
(GND, VSS, VDD) Pins for Digital I/O Pads
4
Spacers to Elevate Board
4
4-40 x 5/16” Screws for Spacers
Table 6. XR-T5794 Demo Board Parts List
Rev. 2.00
10
XRT5794ES
C14
R11
R12
TXCLK2
TXPOS2
TXNEG2
TXCLK1
TXPOS1
TXNEG1
120 75
XR--T5794
P2
C3
C7
R20 1 S2 0
E6
R17
R18
T9
TXOUT4
120 75
C17
120 75
E9
TXEN2
TXEM1
T6
ZSEL
LPEN2
LPEN1 E5
C13
LPMOD1
R9
LPMOD2
E1/TIB
R10
T5
TXOUT3
1 S3 0
E8
LPMOD3
R15
LPMOD4
R16 T8
LPEN3
LPEN4
C15
MONEN
TXEN3
TXEN4 E7
R13
R21
R14 T7
120 75
120 75
MONOUT
RXPOS2
RXNEG2
RXPOS1
RXNEG1
LOS2
LOS1
VSS
75
120
GND
RXIN4
P1
75
120
RXIN3
R1
R2
75
120
RXIN2
T1
T2
T3
R3
R4
E1
C10
E2
1
C9
R5
R6
S1
0
T4
C12
VDD
R7
R8
C11
E3
C6
*
E4
C2
*
R19
C5
C1
C8
C4
U1
RXPOS3
RXNEG3
RXPOS4
RXNEG4
LOS4
LOS3
MSEL0
MSEL1
MSEL2
C16
TXOUT2
TXOUT1
TXCLK4
TXPOS4
TXNEG4
TXCLK3
TXPOS3
TXNEG3
75
RXIN1
Figure 1. XR-T5794 Demo Board Component Layout
Rev. 2.00
11
120
XRT5794ES
VDD
T1
TIP
RING
R2
120
E1
1
PE 65834
1:1
0.1mF
2
3
TIP
TIP
RING
T2
R4
120
PE 65834
1:1
0.1mF
RING
E2
1
8
7
6
5
1
2
3
4
9
10
11
12
13
14
15
16
8
7
6
5
4
3
2
1
2
3
TIP
TIP
R19
10K
VDD
2
6
11
21
26
64
T3
R6
120
PE 65834
1:1
0.1mF
TIP
1
41
38
32
29
2
3
C11
RING
TIP
T4
R8
120
PE 65834
1:1
0.1mF
C12
R7 75
1 1
2 3 4 5 6 1 9 8 7 6 5 4 3 2 2 3 4 5 6 7 8 910 1
0
2
3
4
5
6
7
8
C13
16
15
14
13
12
11
10
9
3
R9 68
E5 1
R10 68
2
333
347
MM M
SS S
EE E
LL L
01 2
TVDD
TVDD
AVDD
VDD
RVDD
TVDD
4 45 55 6 6 6
3 201 2 0 21
L L E L L ZT T
P P1 P PS X X
M M / E EE E E
O O T N NL N N
D D1 1 2 1 2
1 2
111
89089
T TM L L
X XOP P
E E NE E
N NE N N
4 3M 4 3
XR-T5794
TTTTTT
XXXXXX
N P C NP C
E OL E OL
GS K GS K
111 222
5 5 55 5 5
34 56 7 8
T T T TT T
X X X XX X
C P N CP N
L O E L OE
K S GKS G
4 4 4 3 33
11 1 1 1 1
234567
2 2
7 8
L L
PP
MM
OO
DD
4 3
TVSS
RVSS
DVSS
AVSS
TVSS
TVSS
T5
3
R11 68
E6 1
R12 68
T6
PE 65839
C15 0.1mF
20
35
36
5
44
49
59
65
68
0.1mF
PE 65839
C14 0.1mF
2
RXIN1
RXIN2
RXIN3
RXIN4
3 AGND
67 AGND
R R RR
X X XX
L L NP NP
OOE O E O
S S GS GS
1 21 1 2 2
3 44 4 4 4
9 05 6 7 8
E3
R5 75
TIP
1 R20 10K
3
R13 68
E7 1
R14 68
2
VSS
T7
PE 65839
C16 0.1mF
3
R15 68
E8 1
R16 68
2
TXOUT1 63
TXOUT2 66
TXOUT3 4
TXOUT4 7
MOUT 1
R R RR
X X XX
P N P NL L
O E O EOO
S G S GSS
3 3 4 443
2 2 23 3 3
2 3 4 5 01
T8
PE 65839
C17 0.1mF
3
2
E9 1
R17 68
T9
R18 68
PE 65839
E4
1
2
3 VDD
C1 +
10mF
VSS
VSS
C3
C4
C5
0.1mF
0.1mF 0.1mF
1 35 791 1 1 1 1 222
1 3 5 791 35
P1
11 1 1 1 22 22
24 6 8 02 4 6 8 024 6
1 35 7 91 1 1 1 1 222
1 3 57 91 3 5
P2
1 1 1 1 1 22 22
2 46 8 0 2 4 6 80 24 6
C2
10mF +
Figure 2. XR-T5794 Demo Board Circuit Diagram
Rev. 2.00
12
C6
C7
C8
0.1mF
0.1mF
0.1mF
TIP
TIP
RING
TIP
TIP
RING
TIP
TIP
RING
TIP
TIP
RING
TIP
TIP
RING
XRT5794ES
Notes
Rev. 2.00
13
XRT5794ES
Notes
Rev. 2.00
14
XRT5794ES
Notes
Rev. 2.00
15