View XR-T5794IV_628294.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

XR-T5794
...the analog plus company TM
Quad E-1 Line Interface Unit
June 1997-3
FEATURES D Meets CCITT G.703 Pulse Mask Template for 2.048Mbps (E1) Rates D Transmitter and Receiver Interfaces Can Be: - Single Ended, 75 Capacitive or Transformer Coupled - Balanced, 100 or 120 Transformer Coupled D Minimum Return Loss is 20dB (Receive) and 18dB (Transmit), Exceeds G.703 and ETSI 300 166 Specifications D Bipolar Outputs can be Disabled Individually (High Z Outputs) D System Interface is TTL Compatible on Digital Input and TTL/CMOS Compatible On Digital Output Pins GENERAL DESCRIPTION The XR-T5794 is an optimized line interface unit, built using low power CMOS technology. The device contains four independent E1 channels for primary rate, PCM applications up to 2.048Mbps. Each channel performs the driver and receiver functions necessary to convert bipolar signals to TTL/CMOS compatible logic levels and vice versa. The device supports single ended or balanced line interfaces on each channel, thereby providing the user an option of reducing system cost and board space by replacing the transformer with a capacitor. Each of the four drivers can be independently disabled, allowing maximum flexibility in system power management. Output pulses are fully CCITT G.703 compliant. Moreover, the return loss is at least 18dB over a frequency range of 51kHz to 3.072MHz. The slicing circuit in the receive path is able to tolerate a maximum of 12dB of cable loss with a minimum input ORDERING INFORMATION
D Individual Channel Loss of Signal Detection, Local and Remote Digital Loopback D Fifth Driver For Monitoring and Testing D Low Power, CMOS Technology D Over-temperature Protection APPLICATIONS D Multi-Line E1 Interface Cards D E1 Network Equipment - Multiplexers - Cross Connects - Switching Systems D Fault Tolerant Systems
sensitivity of 600mV over the operating temperature range. Return loss on the receive interfaces is minimum 20dB from 51kHz to 3.072MHz. Local and remote loopbacks can be performed on any of the four channels. A separate loss of signal (LOS) detection circuitry and a LOS pin is provided for each input. A fifth transmitter has been provided to support dedicated monitoring and testing purposes on any of the eight bipolar paths. For designers not requiring the fifth (monitor) driver, EXAR offers the XR-T5793, a pin compatible version of the XR-T5794. The XR-T5794 is targeted for multi-line E1 line card applications where real estate, low power consumption and back-up redundancy are critical. Also, the device may be used in T1 applications (1.544Mbps) which do not require meeting the DSX-1 cross connect pulse template.
Part No. XR-T5794IJ XR-T5794IV
Package 68 Lead PLCC 80 Lead TQFP (14x14x1.4 mm)
Operating Temperature Range -40C to +85C -40C to +85C
Rev. 2.02
E1994
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 z (510) 668-7000 z (510) 668-7017 1
XR-T5794
BLOCK DIAGRAM
75 Unbalanced (Without Transformer) Impedance Selectable Receivers. Return Loss Exceeds G.703
TIP 0.47mF 75 Level Detector RXIN 100 or 120 E1/T1LOOPEN(1.4) LPMOD(1.4) Peak Detector
Transceiver 1 Transceiver 2 Transceiver 3 Transceiver 4 LOS Slicer
L o c a l / R e m o t e L o o p b a c k
120 Balanced TIP (or 100 ) RX INPUT RING Impedance Selectable Tristate Drivers Return Loss Exceeds ETSI 300 166
PE-65834 TTI 7148
RXPOS RXNEG
Slice Voltage
2
LOS Threshold Based on G.775
120 ,100 or 75 balanced
TXOUT ROUT1 TXEN
TIP TX OUTPUT RING
PE-65839 TTI 7149
Driver
TXPOS TXNEG TXCLK
75 Unbalanced (Without Transformer)
TIP 0.47F
Channel 1 ROUT1 Channel 2 Driver Channel 3 Channel 4 MUX MOUT
MSEL (0.2) MONEM
Note 1R OUT = 68 for 120 line impedance, ROUT = 62 for 100 line impedance, ROUT = 68 for 75 line impedance
Figure 1. Block Diagram
Rev. 2.01 2
XR-T5794
PIN CONFIGURATION
TXEN3 TXEN4 TXOUT4 TV DD TV TXOUT3 AGND TV DD MOUT TV AGND TXOUT2 TV TV DD TXOUT1 TXEN1 TXEN2
SS SS SS
2 1 68 MONEN AVDD TCLK4 TXPOS4 TXNEG4 TXCLK3 TXPOS3 TXNEG3 LOOPEN4 LOOPEN3 GND VDD RXPOS3 RXNEG3 RXPOS4 RXNEG4 RVDD
10
60
26 27
LPMOD4 LPMOD3 RXIN4 LOS4 LOS3 RXIN3 MSEL0 MSEL1 RGND RGND MSEL2 RXIN2 LOS1 LOS2
44 43
RXIN1 LPMOD2 LPMOD1
LOSLVS AVSS TXCLK2 TXPOS2 TXNEG2 TXCLK1 TXPOS1 TXNEG1 LOOPEN2 LOOPEN1 E1/T1VSS RXPOS2 RXNEG2 RXPOS1 RXNEG1 RVSS
68 Lead PLCC
LOSLVS AVSS AVSS AVSS TXCLK2 TXPOS2 TXNEG2 TXCLK1 TXPOS1 TXNEG1 LOOPEN2 LOOPEN1 E1/T1VSS RXPOS2 RXNEG2 RXPOS1 RXNEG1 RVSS RVSS 60 NC NC TXEN2 TXEN1 TXOUT1 TVDD TVSS TXOUT2 AGND TVSS MOUT TVDD AGND TXOUT3 TVSS TVDD TXOUT4 TXEN4 TXEN3 NC 61 41 40 NC NC LPMOD1 LPMOD2 RXIN1 LOS2 LOS1 RXIN2 MSEL2 RGND RGND RGND MSEL1 MSEL0 RXIN3 LOS3 LOS4 RXIN4 LPMOD3 LPMOD4 80 1 20 21
80 Lead TQFP (14 x 14 x 1.4 mm)
Rev. 2.01 3
NC MONEN AV DD AV DD TXCLK4 TXPOS4 TXNEG4 TXCLK3 TXPOS3 TXNEG3 LOOPEN4 LOOPEN3 GND V DD RXPOS3 RXNEG3 RXPOS4 RXNEG4 RVDD RV DD
XR-T5794
PIN DESCRIPTION
PLCC Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 SQFP Pin # 71 72 73 74 75 76 77 78 79 2 3,4 5 6 7 8 9 10 11 12 13 14 15 16 17 Symbol MOUT TVDD AGND TXOUT3 TVSS TVDD TXOUT4 TXEN4 TXEN3 MONEN AVDD TXCLK4 TXPOS4 TXNEG4 TXCLK3 TXPOS3 TXNEG3 LOOPEN4 LOOPEN3 GND VDD RXPOS3 RXNEG3 RXPOS4 Type O VDD GND O VSS VDD O I I I VDD I I I I I I I I GND VDD O O O Description Signal Monitor Output. If MONEN=1, this output tracks the selected signal. Hi-Z otherwise. The channel selection is done using MONSEL[2..0] inputs. Transmit VDD. )5V ($5%). Analog Ground. Transmitter 3 Output. Transmitter 3 bipolar output connected to coupling capacitor or pulse transformer by a resistor. Transmit VSS. -5V ($5%). Transmit VDD. +5V ($5%). Transmitter 4 Output. Transmitter 4 bipolar output connected to coupling capacitor or pulse transformer by a resistor. Transmitter 4 Output Enable. If driven high the transmitter 4 output drivers are enabled. Hi-Z otherwise. Transmitter 3 Output Enable. If driven high the transmitter 3 output drivers are enabled. Hi-Z otherwise. Monitor/Test Output Enable. If driven high the output driver of the MOUT output is enabled. Hi-Z otherwise. Analog VDD. Transmitter 4 Clock Input. Apply logic one when RZ signals are supplied to data inputs. Transmitter 4 Positive Data In. Positive data input in NRZ or RZ format for transmitter 4. Transmitter 4 Negative Data In. Negative data input in NRZ or RZ format for transmitter 4. Transmitter 3 Clock Input. Apply logic one when RZ signals are supplied to data inputs. Transmitter 3 Positive Data In. Positive data input in NRZ or RZ format for transmitter 3. Transmitter 3 Negative Data In. Negative data input in NRZ or RZ format for transmitter 3. Loop Enable 4. If driven high the specified loop type will be enabled for channel 4. Otherwise normal operation will continue. Loop Enable 3. If driven high the specified loop type will be enabled for channel 3. Otherwise normal operation will continue. Digital Ground. Digital VDD. +5V ($5%). Receiver 3 Positive Data Out. Positive data output in NRZ or RZ format for receiver 3. Receiver 3 Negative Data Out. Negative data output in NRZ or RZ format for receiver 3. Receiver 4 Positive Data Out. Positive data output in NRZ or RZ format for receiver 4.
Rev. 2.01 4
XR-T5794
PIN DESCRIPTION (CONT'D)
PLCC Pin # 25 26 27 SQFP Pin # 18 19, 20 21
Symbol RXNEG4 RVDD LPMOD4
Type O VDD I
Description Receiver 4 Negative Data Out. Negative data output in NRZ or RZ format for receiver 4. Receive VDD. +5V ($5%). Loop Mode 4. If driven high the loopback mode of channel 4 will be set to remote loop. Otherwise theloopback mode will remain at local loop. The actual loopback will be activated when the LOOPEN4 is asserted. Loop Mode 3. If driven high the loopback mode of channel 3 will be set to remote loop. Otherwise the loopback mode will remain at local loop. The actual loopback will be activated when the LOOPEN3 is asserted. Receiver 4 Input. Receiver 4 bipolar input connected to coupling capacitor or pulse transformer. Receiver 4 Loss Of Signal. Asserted during LOS condition. Clear otherwise. Receiver 3 Loss Of Signal. Asserted during LOS condition. Clear otherwise. Receiver 3 Input. Receiver 3 bipolar input connected to coupling capacitor or pulse transformer. Monitor Channel Select 0. Select line, used to select a channel for monitoring using the MOUT pin based on the following assignment: MSEL2 0 0 0 0 1 1 1 1 MSEL1 0 0 1 1 0 0 1 1 MSEL0 0 1 0 1 0 1 0 1 SELECTS Line 1 Receive Line 2 Receive Line 3 Receive Line 4 Receive Line 1 Transmit Line 2 Transmit Line 3 Transmit Line 4 Transmit
28
22
LPMOD3
I
29 30 31 32 33
23 24 25 26 27
RXIN4 LOS4 LOS3 RXIN3 MSEL0
I O O I I
Note The monitoring is only done on the NRZ data output signals from the receiver or from the transmitter line side.
34 35 36 37 38 39 40 41 42
28 29, 30 31 32 33 34 35 36 37
MSEL1 RGND RGND MSEL2 RXIN2 LOS1 LOS2 RXIN1 LPMOD2
I GND GND I I O O I I
Monitor Channel Select 1. See table above. Receive Ground. Receive Ground. Monitor Channel Select 2. See table above. Receiver 2 Input. Receiver 2 bipolar input connected to coupling capacitor or pulse transformer. Receiver 1 Loss Of Signal. Asserted during LOS condition. Clear otherwise. Receiver 2 Loss Of Signal. Asserted during LOS condition. Clear otherwise. Receiver 1 Input. Receiver 1 bipolar input connected to coupling capacitor or pulse transformer. Loop Mode 2. If driven high the loopback mode of channel 2 will be set to remote loop. Otherwise the loopback mode will remain at local loop. The actual loopback will be activated when the LOOPEN2 is asserted.
Rev. 2.01 5
XR-T5794
PIN DESCRIPTION (CONT'D)
PLCC Pin # 43 SQFP Pin # 38
Symbol LPMOD1
Type I
Description Loop Mode 1. Iif driven high the loopback mode of channel 1 will be set to remote loop. Otherwise the loopback mode will remain at local loop. The actual loopback will be activated when the LOOPEN1 is asserted. Receive VSS. -5V ($5%). Receiver 1 Negative Data Out. Negative data output in NRZ or RZ format for receiver 1. Receiver 1 Positive Data Out. Positive data output in NRZ or RZ format for receiver 1. Receiver 2 Negative Data Out. Negative data output in NRZ or RZ format for receiver 2. Receiver 2 Positive Data Out. Positive data output in NRZ or RZ format for receiver 2. Digital VSS. -5V ($5%). E1/T1- Selection. Apply logic one to select the receive data threshold appropriate for E1 operation. Connect to ground to select the T1 data threshold. Loop Enable 1. If driven high the specified loopback mode will be enabled for channel 1. Otherwise normal operation will continue. Loop Enable 2. If driven high the specified loopback mode will be enabled for channel 2. Otherwise normal operation will continue. Transmitter 1 Negative Data In. Negative data input in NRZ or RZ format for transmitter 1. Transmitter 1 Positive Data In. Positive data input in NRZ or RZ format for transmitter 1. Transmitter 1 Clock Input. Apply logic one when RZ signals are supplied to data inputs. Transmitter 2 Negative Data In. Negative data input in NRZ or RZ format for transmitter 2. Transmitter 2 Positive Data In. Positive data input in NRZ or RZ format for transmitter 2. Transmitter 2 Clock Input. Apply logic one when RZ signals are supplied to data inputs. Analog VSS. Loss of Signal Voltage Select. Apply logic one to select LOS voltage level appropriate for 120 balanced receiver operation. Connect to ground to choose LOS voltage for 75 unbalanced operation. Transmitter 2 Output Enable. If asserted the transmitter 2 output drivers are enabled. High-Z otherwise. Transmitter 1 Output Enable. If asserted the transmitter 1 output drivers are enabled. High-Z otherwise. Transmitter 1 Output. Transmitter 1 bipolar output connected to coupling capacitor or pulse transformer through a resistor. Transmit VDD. +5V ($5%). Transmit VSS. -5V ($5%).
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
41, 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57, 58, 59 60
RVSS RXNEG1 RXPOS1 RXNEG2 RXPOS2 VSS E1/T1LOOPEN1 LOOPEN2 TXNEG1 TXPOS1 TXCLK1 TXNEG2 TXPOS2 TXCLK2 AVSS LOSLVS
VSS O O O O VSS I I I I I I I I I VSS I
61 62 63 64 65
63 64 65 66 67
TXEN2 TXEN1 TXOUT1 TVDD TVSS
I I O VDD VSS
Rev. 2.01 6
XR-T5794
PIN DESCRIPTION (CONT'D)
PLCC Pin # 66 67 68 SQFP Pin # 68 69 70 1, 39, 40, 61, 62, 80 Symbol TXOUT2 AGND TVSS NC Type O GND VSS Description Transmitter 2 Output. Transmitter 2 bipolar output connected to coupling capacitor or pulse transformer through a resistor. Analog Ground. Transmit VSS. -5V ($5%). No Connect.
Rev. 2.01 7
XR-T5794
DC ELECTRICAL CHARACTERISTICS
Test Conditions: TA = -40C to 25C to 85C, all VDDs = 5V $5%, all VSSs = -5V $5%, all GNDs = 0V
Symbol DC Parameters VDDs VSSs Inputs VIH VIL IPDC Outputs VOH VOH VOL RXP RXCL RXIWT RXTI RXEI RXLOS RIN PD PD PC PC PC PVDD PVSS High Level Output High Level Output Low Level Output Receiver Sensitivity Allowed Cable Loss (0dB=2.4V) Interference Margin (E1) Receiver Slicing Level (T1)1 Receiver Slicing Level (E1)1 Receiver LOS Threshold Input Resistance Power Dissipation Power Dissipation Power Consumption 752 Power Consumption 1002 Power Consumption 1202 Power Supply Requirement Power Supply Requirement 2.5 400 250 500 475 450 680 280 833 860 830 Pc/2 + 5mW Pc/2 - 5mW 0.6 0 0 16 60 45 65 50 0.2 70 55 0.3 10 10 3.5 2.4 0.4 4.2 12 12 V V V Vp dB dB dB % % V kW mW mW mW mW mW mW mW All Drivers in High-Z All 1's Transmit & Receive All 1's Transmit & Receive All 1's Transmit & Receive Up to 3.072MHz 1.024MHz (E1) 772kHz (T1) With 6dB Cable Loss Peak Voltage % Peak Voltage % IOH = -10mA IOH = -40mA IOL = 1.6mA High Level Input Low Level Input Input Pull Down Current 2.0 0.8 40 V V mA DC Supply Positive DC Supply Negative 4.75 -4.75 5.00 -5.00 5.25 -5.25 V V Parameter Min. Typ. Max. Unit Conditions
Receiver Specifications
Power Specifications (Without Monitor Channel)
Notes 1 Selected by E1/T1 2 Power consumption = power dissipation + power to the cable. Bold face parameters are covered by production test and guaranteed over operating temperature range.
Specifications are subject to change without notice
Rev. 2.01 8
XR-T5794
AC ELECTRICAL CHARACTERISTICS Test Conditions: TA = -40C to 25C to 85C, all VDDs = 5V $5%, all VSSs = -5V $5%, all GNDs = 0V
Symbol VTXOUT VTXOUT VTXOUT TXPW TXPW PNIMB T1 T2 T3 T4 T5 TR TF T6 T7 T8 T9
Parameter Output Pulse Amplitude (75) Output Pulse Amplitude (120) Output Pulse Amplitude (100) Pulse Width (2.048MHz)
Min. 2.13 2.70 2.3 224 274 -5
Typ. 2.37 3.0 3.0 244 324
Max. 2.60 3.30 3.7 264 374 5
Unit V V V ns ns % ns ns
Conditions
Determined by TX Clock Determined by TX Clock
Pulse Width (1.544MHz)
Pos/Neg Pulse Imbalance TXCLK Clock Period (E1) TXCLK Clock Period (T1) TXCLK Duty Cycle Data Setup Time, TDATA to TCLK Data Hold Time, TCLK to TDATA Clock Rise Time Clock Fall Time Receive Data High (E1) Data Propagation Delay Receive Rise Time Receive Fall Time
488 648 48 50 50 30 30 219 244 269 100 50 50 50 52
% ns ns ns ns ns ns ns ns 0dB Cable Loss
Notes Bold face parameters are covered by production test and guaranteed over operating temperature range.
Specifications are subject to change without notice
ABSOLUTE MAXIMUM RATINGS Storage Temperature . . . . . . . . . . . . -65C to +150C Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $7V
Rev. 2.01 9
XR-T5794
TXPOS(n)
TXNEG(n) T4 T5 T4 T5
TXCLK(n) T3 T7 T3 T7
TXOUT(n)
Figure 2. Transmit Timing Diagram
RXIN
T7
T6
T8
T9
RXPOS T7 T9 T8
RXNEG T6
Figure 3. Receive Timing Diagram
T1 or T2 T3 T3
TXCLK(n)
TR
TF
Figure 4. Transmit Clock Timing
Rev. 2.01 10
XR-T5794
RETURN LOSS REQUIREMENTS
75 Transmit Interface 51kHz to 102kHz 102kHz to 2.048MHz 2.048MHz to 3.072MHz Min. 18 18 18 75 Receive Interface 51kHz to 102kHz 102kHz to 2.048MHz 2.048MHz to 3.072MHz Min. 20 20 20 Typ. 30 30 30 Min. 20 20 20 Typ. 22 22 22 Min. 18 18 18 100 Typ. 30 30 30 Min. 20 20 20 100 Typ. 22 22 22 Min. 18 18 18 120 Typ. 30 30 30 Units dB dB dB 120 Typ. 22 22 22 Units dB dB dB
Note The return loss has been measured on the evaluation board coupled via a capacitor and terminated with 75W impedance.
Table 1. Return Loss Requirements (Resistor Tolerance: 1% on Transmit Side, 2% on Receive Side)
Turns Ratio 1:1 1:1 1:1
Line Impedance 75 120 100
RLOAD 75 120 100
Turns Ratio 1:1 1:1.265 1:1.265
Line Impedance 75 120 100
ROUT 68 68 62
Table 2. Input Transformer Requirements
Table 3. Output Transformer Requirements
Magnetic Supplier Information: Pulse Telecom Product Group P.O. Box 12235 San Diego, CA 92112 Tel. (619) 674-8100 Fax. (619) 674-8262 Transpower Technologies, Inc. 24 Highway 28, Suite 202 Crystal Bay, NV 89402-0187 Tel. (702) 831-0140 Fax. (702) 831-3521
Rev. 2.01 11
XR-T5794
SYSTEM DESCRIPTION This device is a quad E1 transceiver which provides electrical interface for 2.048Mbps applications. Its unique architecture includes four receiver circuits that convert CCITT G.703 compliant bipolar signals to TTL compatible logic levels. Likewise, in the other direction, four transmitters translate TTL compatible logic levels to G.703 compatible bipolar signals. A fifth transmitter circuit is used as a monitor output. One of the four AMI receiver inputs or transmitter outputs can be selected (via MONSEL[2..0] lines) to be monitored. The MOUT output can be disabled using the MONEN signal. This device supports two different types of loopback functions. Each of four channels can be independently looped either in local or remote sides digitally. The remote loopback is performed between the receiver input and transmitter output. To activate the remote loopback on channel n, LOOPENn and LPMODn inputs are driven high. Local loopback on channel n, can be established similarly by driving LOOPENn high and clearing LPMODn inputs. More than one channel can be tested simultaneously. RECEIVERS Each of the four identical E1 line receivers will accept bipolar signals meeting the CCITT G.703 pulse mask requirements. Each input stage consists of a slicing circuitry which samples the incoming pulses at a fixed percentage of the signals maximum amplitude. The slicing voltage level is generated using a precision peak detector. The receiver section can tolerate up to 12dB of line loss (measured at 1.024MHz). A loss of signal (LOS) is detected on any inputs by input fail circuitry. There is an independent LOS pin dedicated for each of the receivers. The LOS detection is based on signal energy instead of number of zeros. A balanced signal (100 or 120) must be coupled by a transformer. An unbalanced signal (75) may be coupled via a capacitor or transformer coupled. TRANSMITTERS This device contains five identical CCITT G.703 compliant transmitters which meet the return loss requirements. Each transmitter is a single-ended voltage driver. External resistors are used to maintain an accurate source impedance that has a high return loss to the transformer or the capacitor. Each of the drivers can be individually disabled, this is required in fault tolerant applications where redundancy is a requirement. During power-down mode of operation the bipolar outputs can be disabled. To protect the data integrity during a brownout, the output pulse amplitudes are reduced by a factor of 25% if the supply drops below an internally set limit. Transmission is possible either with or without a clock. If a clock is used, the transmit input data must consist of full-width NRZ pulses, and the transmitter output pulse width is determined by the duty cycle of the clock. If the transmit clock is tied high, the transmitter output pulses are determined by the input data pulse width. In this mode, RZ data must be supplied to the device.
TXP TXN
RXIN
TXOUT RX TX LPMOD=1 LPEN=1 RXP RXN
Remote Loopback
TXP TXN
RXIN
TXOUT RX TX LPMOD=0 LPEN=1 RXP RXN
Local Loopback
Figure 5. Loopback Configurations
Rev. 2.01 12
XR-T5794
Output Transformer Selection The 1:1.265 ratio output transformer is recommended for the XR-T5794 because this ratio gives the best possible transmitter output return loss for 120 balanced E1 service. However, other transformers may provide an adequate return loss for many applications. The two characteristics that determine series build-out resistor requirements are: D Driver output impedance is less than 5. D Vs, which is the driver open circuit output voltage, is 4.5V peak. The following method may be used to determine transformer suitability for a given use. 1. List the application requirements. Transformer Ratio = 1:n Vo = Peak Output Pulse Amplitude RL= Load Resistance
Rs 1:n 3 Vs 4 2 1 VO RL
3. Calculate the source resistance, RS.
Rs + Req
Vs * 1 Veq
4. Now calculate the theoretical return loss.
Return Loss + 20 log
Req ) Rs Req * Rs
The calculation given below uses the recommended 1:1.265 ratio transformer as an example: Transformer Ratio = 1 :1.265 VO = 3.0V Peak RL = 120
Req +
RL + 120 + 75 1.6 n2
V Veq + no + 3.0 + 2.37V 1.265 Rs + Req Vs * 1 + 75 4.5 * 1 2.37 Veq
+ 67.4
Figure 6. Equivalent Impedance Schematic 2. Calculate equivalent output voltage and load resistance without the transformer.
Req +
RL n2
Rs
V Veq + no
(Datasheet specifies standard value of 68) Calculate the theoretical return loss to determine if the transformer is acceptable.
Req
Vs
Veq
Figure 7. Equivalent Simplified Schematic
Return Loss + 20 log 75 ) 67.4 + 25.5dB 75 * 67.4
Rev. 2.01 13
XR-T5794
269 ns (244 + 25) 20% 10% V = 100% 10% 20% 194 ns (244 - 50) Nominal pulse
50% 244 ns 219 ns (244 - 25)
10% 0% 10% 20%
10% 10%
488 ns (244 + 244)
Note: V corresponds to the nominal peak value
Figure 8. CCITT G.703 Pulse Template
Rev. 2.01 14
XR-T5794
68 LEAD PLASTIC LEADED CHIP CARRIER (PLCC)
Rev. 1.00
D D1 45 x H2 2 1 68 B1 45 x H1 C Seating Plane A2
B D D1 D3 D2
e
R D3 A1 A INCHES SYMBOL A A1 A2 B B1 C D D1 D2 D3 e H1 H2 R MIN 0.165 0.090 0.020 0.013 0.026 0.008 0.985 0.950 0.890 MAX 0.200 0.130 ---. 0.021 0.032 0.013 0.995 0.958 0.930 MILLIMETERS MIN 4.19 2.29 0.51 0.33 0.66 0.19 25.02 24.13 22.61 MAX 5.08 3.30 --0.53 0.81 0.32 25.27 24.33 23.62
0.800 typ. 0.050 BSC 0.042 0.042 0.025 0.056 0.048 0.045
20.32 typ. 1.27 BSC 1.07 1.07 0.64 1.42 1.22 1.14
Note: The control dimension is the inch column
Rev. 2.01 15
XR-T5794
80 LEAD THIN QUAD FLAT PACK (14 x 14 x 1.4 mm, TQFP)
Rev. 3.00
D D1 60 41
61
40
D1
D
80
21
1 A2 e A Seating Plane A1 B
20
C
L
INCHES SYMBOL A A1 A2 B C D D1 e L MIN MAX
MILLIMETERS MIN 1.40 0.05 1.35 0.22 0.09 15.80 13.90 MAX
0.055 0.063 0.002 0.006 0.053 0.057 0.009 0.015 0.004 0.008 0.622 0.638 0.547 0.555 0.0256 BSC 0.018 0.030 0 7
1.60 0.15 1.45 0.38 0.20 16.20 14.10 0.65 BSC 0.45 0.75 0 7
Note: The control dimension is the millimeter column
Rev. 2.01 16
XR-T5794 Notes
Rev. 2.01 17
XR-T5794 Notes
Rev. 2.01 18
XR-T5794 Notes
Rev. 2.01 19
XR-T5794
NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Copyright 1994 EXAR Corporation Datasheet June 1997 Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
Rev. 2.01 20

▲Up To Search▲

Price & Availability of XR-T5794IV

	To Download XR-T5794IV Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .