MH89793 E1 Transceiver with Selectable Impedance Preliminary Information Features ISSUE 1 April 1995 Ordering Information • Complete primary rate 2048kb/s CEPT line driver and receiver MH89793 28 Pin DIL Package Surface Mount Option is available by adding the suffix “S” • Onboard pulse transformers for transmit and receive • Meets latest ETSI requirements [ETSI ETS 300 011 (NET 5)] • Inductorless clock recovery • Loss of signal (LOS) indication • Single +5V operation • Compatible with MT9079 Framer • Selectable termination impedance Description The Mitel MH89793 is a low cost E1 line driver/receiver with clock extraction requiring no external components. Applications The device is suitable for both 120R and 75R applications, by linking external pins. • Primary rate ISDN network Interface • Multiplexer equipment • Private Network links • Isochronous LANS/WANS VDD TxA TxB E2o LOS 0°C to +70°C By combining the MH89793 with Mitel’s E1 framer, the MT9079, a cost effective and efficient interface to E1 lines can be built. VSS TZA1 TZA2 TZA3 TZB1 TZB2 TZC1 TZC2 TZD1 TZD2 Transmit Isolation Transformer Line Driver TLA 6dB Pad TLB Clock Recovery RLA Receive Isolation Transformer RxA RxB RLB Line Receiver EQUIPMENT SIDE LINE SIDE RZA RZB Figure 1 - Functional Block Diagram 4-229 MH89793 Preliminary Information RLA RLB TLA TLB TZD2 TZC2 TZA3 TZB1 TZA2 TZB2 TZD1 TZC1 TZA1 NC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 TXA TXB NC NC NC VDD E20 RXB RXA VSS LOS NC RZA RZB Figure 2 - Pin Connections Pin Description Pin # Name Description 1 RLA Received Line A (Input). The A wire or Tip connection of the E1 receive line is connected to this pin. 2 RLB Received Line B (Input). The B wire or Ring connection of the E1 receive line is connected to this pin. 3 TLA Transmit Line B (Output). The A wire or Tip connection of the E1 receive line connected to this pin. 4 TLB Transmit Line B (Output). The B wire or Ring connection of the E1 receive line connected to this pin. 5 TZD2 Transmit Impedance Select. This pin is connected to pin 4 TLB to select 75Ω impedance. For 120Ω operation this pin is left open circuit. 6 TZC2 Transmit Impedance Select. This pin is connected to pin 3 TLA to select 75Ω impedance. For 120Ω operation this pin is left open circuit. 7 TZA3 Transmit Impedance Select. This pin is connected to pin 9 TZA2 to select 75Ω impedance. For 120Ω operation this pin is left open circuit. 8 TZA3 Transmit Impedance Select. This pin is connected to pin 10 TZB2 to select 120Ω impedance. For 75Ω operation this pin is left open circuit. 9 TZA2 Transmit Impedance Select. This pin is connected to pin 7 TZA3 to select 75Ω impedance. For 120Ω operation this pin is left open circuit. 10 TZB2 Transmit Impedance Select. This pin is connected to pin 8 TZB1 to select 120Ω impedance. For 75Ω operation this pin is left open circuit. 11 TZD1 Transmit Impedance Select. This pin is connected to pin 4 TLB to select 120Ω impedance. For 75Ω operation this pin is left open circuit. 12 TZC1 Transmit Impedance Select. This pin is connected to pin 3 TLA to select 120Ω impedance. For 75Ω operation this pin is left open circuit. 13 TZA1 Transmit Impedance Select. This pin is connected to pin 9 TZA2 to select 120Ω impedance. For 75Ω operation this pin is left open circuit. 14 NC No Connection. This pin is used for internal connection. 15 TXA Transmit A (Input). A unipolar signal from the framer device used in conjunction with TXB is used to generate the bipolar output signal. 4-230 MH89793 Preliminary Information Pin Description (Continued) Pin # Name Description 16 TXB Transmit B (Input). A unipolar signal from the framer device used in conjunction with TXA is used to generate the bipolar output signal. 17 NC No Connection. This pin is used for internal connection. 18 NC No Connection. This pin is used for internal connection. 19 NC No Connection. This pin is used for internal connection. 20 VDD D.C. Power (Input). +5V supply. 21 E2o 2048kHz Extraction Clock (Output). This clock is extracted by the device from the received signal. It is used internally to clock in data received from RLA and RLB. 22 RXB Receive B (Output). This pin is connected to the negative receive pin of the framer and provides a signal of the same format as RXA. 23 RXA Receiver A (Output). The bipolar CEPT signal received by the device at RLA and RLB input is converted to a unipolar format and output at this pin. This pin is connected to the positive receive pin of the framer. 24 VSS Ground (Input). D.C. power return path. 25 LOS Loss of Signal (Output). This pin goes low when 128 contiguous zeros are received on the RLA and RLB inputs. LOS is reset when 64 ones are received in dual E1 frame periods. 26 NC No Connection. This pin is used for internal connection. 27 RZA Receive Impedance Select. This pin is connected to pin 17 RZB to select 75Ω input impedance. For 120Ω operation this pin is left open circuit. 28 RZB Receive Impedance Select. This pin is connected to pin 16 RZA to select 75Ω input impedance. For 120Ω operation this pin is left open circuit. Functional Description Bipolar Line Transmitter The MH89793 is an E1 digital trunk interface which when used with an approved framer will conform to CCITT recommendation G.703 for PCM30 and I.431 for the ISDN. The functions provided include line driver and receiver circuitry, inductorless clock recovery, and loss of signal indication. The MH89793 transmitter interfaces to the transmission line through an internal pulse transformer which combines the TxA and TxB data into an AMI line coded signal. This is then passed through the 6dB pad prior to being applied to the line. Bipolar Line Receiver The MH89793 receiver interfaces to the transmission line through an internal pulse transformer which splits the received AMI lines signal into RxA and RxB. The line impedance is selected by linking appropriate option pins. Attenuation of the transmission line shall not exceed 6dB (at 1024kHz) and attenuation characteristics shall be close to the “square root of f”. Af (dB) = AFref (dB)* Clock Extractor The MH89793 contains a clock extraction circuit that generates the E2o clock from the received data without the use of external crystals or a tunable inductor. The edge of the E2o extracted clock approximately aligns with the centre of the received data pulse. √f f ref Where: AF - attenuation at frequency f in dB AFref - attenuation at frequency fref in dB (in kHz) fref - reference frequency (in this case 1024) kHz f - frequency in kHz 4-231 MH89793 Preliminary Information Loss of Signal The circuitry on board the hybrid is capable of detecting 128 continuous ZEROs received on RLA and RLB and indicating this condition as a logic low on pin 9, (LOS). LOS will not reset until 64 ONEs are received in a two E1 frame period. VDD 10K +5 0.1µ 33 2 1 41 RESET TAIS VDD DSTi 26 32 35 TxMF 43 15 TxA RLA 42 16 TxB TLA TxA DSTo 31 MH89793 16 TxB F0i 13 C4i 9 7 8 10 27 28 E8Ko MT9079 8-15 D0-7 18-22 AC0-4 23 23 29 22 RxB R/W 24 RxA 30 27 21 E2i CS TLB 4 2 TZA1 TZA2 TZA3 TZB1 TZB2 RZA RZB 1 3 RLB TZD1 TDZ2 TZC1 TZC2 11 5 12 6 RxA RxB 25 LOS E2o 25 DS Foi 7 IRQ C4i S/P 36 31 26 VSS MT9042 37 Figure 3a - Application Circuit for 75Ω Operation 4-232 NETWORK CONNECTOR MH89793 Preliminary Information VDD 10K +5 0.1µ 33 2 31 26 32 1 41 MH89793 16 RESET TAIS VDD 35 TxMF DSTi 43 15 TxA RLA 42 16 TxB TLA 13 TLB TxA DSTo TxB F0i C4i 9 7 8 10 27 28 E8Ko MT9079 8-15 D0-7 18-22 AC0-4 23 30 23 29 22 27 21 RxB R/W 24 RxA E2i CS 4 NETWORK CONNECTOR 2 TZA1 TZA2 TZA3 TZB1 TZB2 RZA RZB 1 3 RLB TZD1 TDZ2 TZC1 TZC2 11 5 12 6 RxA RxB 25 LOS E2o 25 DS Foi 7 IRQ C4i S/P 36 31 26 VSS MT9042 37 Figure 3b - Application Circuit for 120Ω Operation 4-233 MH89793 Preliminary Information 0.23 Max (5.9 Max) AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAA AAAA AAAAAAAAAAAAAAAAAAAAAAA AAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAA AAAA AAAA AAAA AAA AAAA AAAA AAAA AAAA AAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAA 0.37 Max (9.5 Max) 0.063 Max (1.6 Max) * 0.050 Typ (1.27 Typ) 0.08 Typ (2 Typ) * 0.10 + 0.005 0.020 + 0.005 (2.54 + 0.12) (0.51 + 0.12) 0.060 Typ (1.52) 1.42 Max (36.1 Max) 1.08 Max (27.4 Max) AAAAAAAA AAAAAAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAAAAAA AAAA AAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAA Notes: 1) Not to scale 2) Dimensions in inches). 3) (Dimensions in millimetres). *Dimensions to centre of pin. Figure 4 - Mechanical Data for 28 Pin Surface Mount Hybrid 0.1 (2.5) 0.89 (22.6) 0.04 (1.02) 0.06 (1.53) Figure 5 - Recommended Footprint for 28 Pin Surface Mount Hybrid 4-234 0.125+0.015± (3.18+0.38) MH89793 Preliminary Information 0.23 Max (5.9 Max) 0.31 Max (7.9 Max) 0.063 Max(1.6 Min) 0.08 Typ (2 Typ) * 0.100+0.005 (2.54+0.12 * 0.26+0.015 (6.6+0.4) 0.020 + 0.005 (0.5 + 0.12) 0.050 Typ (1.27 Typ) AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAA AAAA AAAAAAAAAAAAAAAAAAAAAAA AAA AAAAAAAAAAAAAAAAAAAAAAA AAAA AAAAAAAAAAAAAAA AAAAAAAA AAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAA AAAAAAAAAAAAAAAAAAAAAAA 0.90 Typ (22.9 Typ) 0.95 Max (24.2 Max) 1.42 Max (36.1 Max) 1 Notes: 1) Not to scale 2) Dimensions in inches). 3) (Dimensions in millimetres). *Dimensions to centre of pin. Figure 6 - Mechanical Data for 28 Pin DIL Hybrid 4-235 MH89793 Notes: 4-236 Preliminary Information