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(R) MH89761 T1 Transmit Equalizer Advance Information Features * * * * Compatible with the MH89760B Transmit equalizer and 6dB loop around circuit 6dB pad for easier loopback testing Programmable for varying degrees of equalization TL TL TI Ri RL RL TxT EIT EA L1 EB EC L2 RCHT RCLT TxR EIR SW RCHR RCLR ISSUE 4 May 1995 Pin Connections 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Description The MH89761 is a programmable transmit equalizer for use with a T1 line interface, specifically the MH89760B. The MH89761 contains a three setting transmit equalizer, and a 6 dB pad for external loop around. The input and output impedance of the circuit is 100. The device is fabricated in thick film hybrid technology and is 2 inches high by 0.5 inches wide. The MH89761 is designed to drive 22 gauge twisted pair from the multiplex equipment to the crossconnect point. Figure 1 shows how the MH89761 is connected to the transmit side of a T1 interface. Ordering Information -40C to 85C MH89761 20 Pin SIP Hybrid MH89760B TR1 OUTA +12V L2 C2 1: OUTB MH89761 * 1: :0.5 * R1 L1 C1 * * S1 S2 EIT EIR TxT TxR EA EB EC SW RCLT RCHT RCLR RCHR Ti Ri TL RL ** * * * S3 S4 S5 S6 S7 R1 = 150 C1 = .01F C2 = .47F L1 = 33H L2 = 33H TR2 RxT 1: 1: 1: RxR * * Figure 1 - Connection Diagram 4-93 MH89761 Applications The MH89761 can be connected to the MH89760B as illustrated in Figure 1. All pins on the MH89761 not shown connected in Figure 1 should be left open. The internal circuit of the equalizer is shown in Figure 2. The MH89761 has two separate circuits; a 6dB pad and an equalizer. Ti and Ri are inputs to the 6dB pad on the device. The outputs of the pad are brought out on TL and RL. The 6dB pad is provided to loopback the transmit signal back to the receive without altering the equalizer settings. The 4 pole double throw relay shown in Figure 1 permits connection of the output of the transformer TR1 to either the equalizer or the fixed 6dB pad. For normal operation and transmission out to the line, the transformer should be connected to the equalizer inputs EIT and EIR. Enabling the relay will switch the connection through the 6dB pad for loopback diagnostics. The MH89761 is designed to accept output from the secondary of the T1 transmit transformer and condition it for transmission over twisted pair. The seven switches (S1 to S7) permit configuration of the equalizer for different line lengths. The pulse amplitude at the secondary of TR1 is approximately 6V. Passing this signal through the equalizer with zero line length setting on the switches will result in attenuation of the pulse by 6dB. This will ensure that the pulse fits in the template shown in Figure 3 and meets DSX-1 requirements. By switching in different C and L components, the frequency and phase response of the equalizer can be altered as shown in Figures 4 and 5. Note that the circuit attenuates lower frequencies more than higher frequencies. Consequently, when a pulse is passed through the equalizer, lower frequency components in the signal are attenuated more than higher frequency components. The intention is to compensate for the attenuation properties of twisted pair cable, which tends to attenuate higher frequencies more than lower frequencies. The net result is that a preequalized pulse will meet DSX pulse requirements after traversing a specific length of cable. The cable length indicated along withthe equalizer switch settings in Figure 4 are specific to 22 awg ABAM cable interfaced to an MH89760B equipped with a Filtran TFS2573 transformer. Different equalizer settings may be more appropriate for other cable and transformer types. Figure 6 shows the generic switch settings for different levels of equalization. Reference: Manufacturer: ANSI T1.102 - 1987, Section 2.2 Filtran Ltd. (613) 226-1626 Advance Information Ti * 50 50 * 50 TL * 6dB Pad 100 * 50 Ri 50 50 * S5 * RL * 200 4870pF S4 * 390 2150pF * * * * EiT * 50 50 * 50 TxT * EQUALIZER 100 * * 12 27 10H S1 22H * 50 EiR 50 * S2 S3 50 * * TxR 2150pF S6 * 4870pF 200 * * S7 * Figure 2 - 6dB Pad and Equalizer Pin 4-94 Advance Information MH89761 t1 115% 105% t2 t3 t4 SYMBOL t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 TIME 100 ns 75 ns 175 ns 50 ns 100 ns 100 ns 75 ns 50 ns 50 ns 375 ns 150 ns 130 ns 175 ns AAAA AA AAAAAA AAAA AAA AAAAAAAAAAAAAAAAA AA A AAA AAAA AA AAA AA AAA AA AA AA A AA AA A Nominal A AAA A A AAA AAAA Pulse Shape A AAA AAAA AAAA AAA t5 t6 AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAA AAAA 50% AAA t7 AAAA AAAA AAA AAAA AAA AAA AAAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAAA AAA AAA AAAA AAAA AAA AAAA AAA AAAA AAA AAA AAAA AAAA AAA t10 AAAA A t9 AAA t8 A AAA A AAA AA A AAA AA AAA AA AAA AAA 5% AA AA AAA A AA AAAAAA AAAAAAAAAA AAAA AA AAA AAA AAAAAAAA AA AAAA AA AAAA AA AA A AAA AAAAAAA AA AA AAAA A AA A AAAAAAA AA AAAA AA AAA AAAA -7% AAA A AAAA AAA AAA AAAA AA AA AAA A AA AA AAA AAA -5% AAA AA A A AA AA AA AA AA -20% AA A AA A AA AA A AA AAA AA A AA AA AA AAAAAA AAAA AAAAA AAAA AA 95% 90% 80% -45% t11 Note 1: Template is not to scale t12 t13 Figure 3 - DSX-1 Line Pulse Template (Reference: ANSI T1.102-1987) Attenuation Versus Frequency 0 AAAAA AA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAA AAAAA AA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAResistiveAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA Note: 100 Load AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA Short Medium Long AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA 0-150' 150-450' 450-655' AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S1 CLOSE OPEN OPEN AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S2 OPEN CLOSE OPEN AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA LONG AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S4 OPEN OPEN CLOSE AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S4 OPEN CLOSE OPEN AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAMEDIUMAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S5 OPEN OPEN CLOSE AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S6 OPEN CLOSE OPEN AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA S7 OPEN OPEN CLOSE AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA Equalizer settings AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAANote: The equalizer shown here is optimum for 22 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgauge ABAM cable and Filtran TFS2573 AAAAAAAA AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAtransformer. The distance settings are approximate AAAA AAA AAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAA AAAA AA AAA AAAAAAAA 1 A T2 T E N U A3 T I O N 4 d B 5 and may vary with cable and transformer type SHORT 6 100K 200K 500K 1000K 2000K 5000K 10M 20M 50M 100M Frequency (Hz) Figure 4 - Typical Frequency Response of the Equalizers 4-95 MH89761 24 Phase Angle Versus Frequency Advance Information 20 16 D E G R E 12 E S AAAAAAA AAAAAA AAAAAAA AAAAAAAAAAA AAAAAAAAAA AAAAAAAAAAA AA AAA AAAAAA AA AAA AAAA AAA AA A AAA AA AA AA AAA AA AA AAA AA AAA AA AA A AAAA AAA AAA AA A AA AA AA A AAA MEDIUM AA A LONG AAA AA AA AAA AA AAA AAA AA A AA AA AA AA AA A AA A AA AA AAA AA A AA AA A AA A AA AA A AA AA A AAA AA A AAA AA A AAA AA AAA AAA AA AA AA AAAA Note: 100 Resistive Load AA A AA A AA AAA AAA AA AAA AA A AAA AAA AA A AAA AA AA AAA AA A AAAA A AA 8 AAAA AAA AA AAAA AAAA AA AA AA AAA AA A AAA AA A AAA AA AA AAA AA A AAAAA AAAAA A AA AAA AA A AAAA A AA AAA AA A AAA AAA AAA AA A AAAAA AAA AA AAA AAA AA A AAA AAA AA AAAA AA AAA AAAA AA AAAA AA AAA AA AAAAA AAA AAA AA AAA AAAAA AAAAA 4 AA AAA AA AAAA AAA AA AAA AAAA AAAA AA AAA AAAAA AA AAAA AAAA AAA AAAA AA AAAAAA AAAA AAAAAA AA AAAA AA AA AA AAAAA AA AAA AAAAAAA AAAAAA A AA AAAAAA AA A AAAAA AAAAA AAAA AA SHORT AAAAAAA AAAAAA AAAAA AAA AAA AAA AA AAA AA A AA AAAAA AAAA AAA 0 100K 200K 500K 1000K 2000K 5000K 10M 20M 50M 100M Frequency (Hz) Figure 5 - Typical Phase Response of the Equalizers S1 S2 S3 - = SWITCH OPENED S4 X = SWITCH CLOSED S5 S6 S7 X - X - X - X X X - X X X - X X X - X X X X X X X X X X X X X X X X X X X X X X X X INCREASING EQUALIZATION NO EQUALIZATION Short Cables MAX. EQUALIZATION Long Cables Figure 6 - Switch Settings for Different Levels of Equalization 4-96 Advance Information MH89761 2.00 + 0.02 (50.8 + 0.5) 0.03 Max. (0.8 Max.) A AAAAAAAAAAAAA AA A AA A AA A AA A AA A AA A AA A AA A AA A AAAA A A AA AAAA AAAAAA A A AA AAAA AAAA A Pin 1 A AA A AA 1 5 10 15 20 0.40 + 0.02 (10.2 + 0.5) Side View 0.010 + 0.002 (0.25 + 0.05) 0.2 Max. (5.1 Max.) 0.05 0.01 (1.3 0.3) 1 Front View 5 0.18 + 0.02 (4.6 + 0.5) * * 0.020 + 0.005 (0.51 + 0.13) 0.10 + 0.01 (2.5 + 0.2) Notes: 1) Not to scale. 2) Dimensions in inches 3) (Dimensions in millimeters) * Dimension to center of pin 0.05 + 0.02 (1.3 + 0.5) Figure 7 - Mechanical Data 4-97 MH89761 NOTES: Advance Information 4-98 |
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