MH89761 T1 Transmit Equalizer Advance Information Features ISSUE 4 • Compatible with the MH89760B • Transmit equalizer and 6dB loop around circuit • 6dB pad for easier loopback testing • Programmable for varying degrees of equalization Pin Connections TL TL TI Ri RL RL TxT EIT EA L1 EB EC L2 RCHT RCLT TxR EIR SW RCHR RCLR 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 100Ω. 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. MH89761 L2 20 Pin SIP Hybrid MH89761 TR1 +12V 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Ordering Information -40°C to 85°C MH89760B OUTA May 1995 • • • • EIT EIR R1 1: :0.5 C2 L1 1: S1 S2 C1 •• OUTB S3 • • • S4 S5 S6 S7 TR2 TxT TxR EA R1 = 150Ω C1 = .01µF C2 = .47µF L1 = 33µH L2 = 33µH EB EC SW RCLT RCHT RCLR RCHR Ti TL Ri RL • RxT 1: 1: 1: • RxR Figure 1 - Connection Diagram 4-93 MH89761 Advance Information 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. Ti 50Ω • • 50Ω TL 50Ω • 6dB Pad 100Ω • 50Ω Ri 50Ω 50Ω • • RL 200Ω S5 • 4870pF • S4 • 390Ω • • 2150pF 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-1➀ 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. • EiT • • TxT 50Ω 50Ω 50Ω • EQUALIZER 100Ω • • 12Ω 27Ω 10µH 22µH S1 • • 50Ω S2 S3 50Ω 50Ω EiR • TxR 2150pF • 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 ➁ 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. ➀ ➁ Reference: Manufacturer: 4-94 ANSI T1.102 - 1987, Section 2.2 Filtran Ltd. (613) 226-1626 S6 • • 4870pF • S7 • 200Ω Figure 2 - 6dB Pad and Equalizer Pin MH89761 Advance Information t1 t2 t3 t4 115% 105% SYMBOL TIME t1 100 ns t2 75 ns t3 175 ns t4 50 ns t5 100 ns t6 100 ns t7 75 ns t8 50 ns t9 50 ns t10 375 ns t11 150 ns t12 130 ns t13 175 ns AAAA AAAA AA AAAA AAAA AA AAAAAAAAAAAAAAAAA AAAA AAAAAA AAA AAAA AAA AAA AA A AAA AA Nominal A AAAA AAA AAAAAA Pulse Shape 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 AAAAA AAA t t 9 8 A AAA A AAA AA AAA AAA AAA AAA AAA AA 5% AAA AAA AA AA AAAA AAA AA A AA A AA A AA A AAA AAAAA AA A AA AAAAAAA AAAA AAAA AAA AAAA AAA AAAAAA AAA AAAAAA AA AA AAAA AAAA A AAA AAA AA AAAAAAA -7% AAAA AA AA AAA AA AAAAAA AAA A AA A AA AA AA A -5% AA AAA AA AAA AAA AA AA -20% AAA A AA AA AAA AA AA A AA A AAA AA AAAA AAAAA AAAAAA AAA AAAA 95% 90% 80% -45% t11 t12 t13 Note 1: Template is not to scale Figure 3 - DSX-1 Line Pulse Template (Reference: ANSI T1.102-1987) Attenuation Versus Frequency 0 1 A T 2 T E N U A 3 T I O N 4 d B 5 AAAA AA AA AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAA AA AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA Note: 100Ω Resistive Load AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAA AAAA Short Medium Long AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA 0-150’ 150-450’ 450-655’ AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA S1 CLOSE OPEN OPEN AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA S2 OPEN CLOSE OPEN AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA LONG AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA S4 OPEN OPEN CLOSE AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA S4 OPEN CLOSE OPEN AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA MEDIUM AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA S5 OPEN OPEN CLOSE AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA S6 OPEN CLOSE OPEN AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA S7 OPEN OPEN CLOSE AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA Equalizer settings AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA Note: The equalizer shown here is optimum for 22 AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA gauge ABAM cable and Filtran TFS2573 AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA A AA A AA A AA A AAAA The distance settings are approximate AAAAA AA AA A AAAA AA A AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAtransformer. AAAAAAAA AAAA 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 Advance Information Phase Angle Versus Frequency 24 20 AA AAA AA AAA AAA AAA AAA A AA AAA AA AAA AAA AAA AAA AAA AAA AAA AAAA AAA AA A AAAA AAA AA AAA AA A AA AA A AA A AA A AA AA AA AAA AA AAA AAA AA A AA A AAAA AA A AA A AA A AAA AA A AAA A AA AA MEDIUM LONG AA AA AA AAAA AAAAA AA AA AA A AA AA AAAA AAAA AA AAAAA AA AA AA A A A AA AAAA A AA A AA AAAA AA AA A AA A AAAA AAAAAA AA A AA A AA Note: 100Ω Resistive Load AA AA AA AAAAA A AA AAA AA AA A AA A AA AA AA AA AAA AAAA A AA A AA A AA A AA 8 AAAA AAA AA A AA AA AA AAA AA AA AAA AAAA A AA AA AA AAAA AAA AA A AA A AAA AAAA AAAA AAAA A A AAAA AAAA AAAA AA AAAAAA A AA A AA A AAAA AAA AAAA AA AA A AA A AAAA AA AA AA AAAA AAA A AA AAAA AA AAA AA A A AAAA AAAAA AA A AA A AA AAAA AAA 4 A AA A AA A AAAA AAAAA AAA AA AA AA AAAA A AA A AA AA AAA AA A AAAA AA AAAAA AAA AAAA AAA AAAA AA AAAA AA AA A AAA AAA AAAA AAAAA AA AAA AA AAA AAAAA AAAA AAAA AA A AA AAA AAAAAA AAA AAA SHORT AAAAA AAAA AAAA AA AAAAA AA AAA AAA AAA AAA AAA AAAAA AAA AAA AA 0 16 D E G R E 12 E S 100K 200K 500K 1000K 2000K 5000K 10M 20M 50M 100M Frequency (Hz) Figure 5 - Typical Phase Response of the Equalizers S1 X - - X - - X - - X - - S2 - X - - X - - X - - X - S3 - - X - - X - - X - - X - = SWITCH OPENED S4 X = SWITCH CLOSED S5 - - - X X X - - - X X X - - - - - - X X X X X X S6 - - - X X X - - - X X X S7 - - - - - - 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 MH89761 Advance Information 0.03 Max. (0.8 Max.) 2.00 + 0.02 (50.8 + 0.5) AAAAAAAAAAAAA A AA A AA A AA A AA A AA A AA A AA A AA A AA A AA A A AA AAAA AAAA AA A AA A A AA AAAA AAAA A AA A Pin 1 AA 1 5 10 15 20 0.40 + 0.02 (10.2 + 0.5) Side View Front View 0.010 + 0.002 (0.25 + 0.05) 1 0.2 Max. (5.1 Max.) 5 0.05 ± 0.01 (1.3 ± 0.3) 0.18 + 0.02 (4.6 + 0.5) * 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) * 0.020 + 0.005 (0.51 + 0.13) 0.10 + 0.01 (2.5 + 0.2) Figure 7 - Mechanical Data 4-97 MH89761 NOTES: 4-98 Advance Information