The 1417G4A and 1417H4A transceivers are highspeed, cost-effective optical transceivers that are compliant with the International Telecommunication Union Telecommunication (ITU-T) G.957 specifications for use in ATM, SONET, and SDH applications. The 1417G4A operates at the OC-3/STM-1 rate of 155 Mbits/s, and the 1417H4A operates at the OC-12/STM-4 rate of 622 Mbits/s. The transceivers feature Agere Systems' high-reliability optics and are packaged in a narrow-width plastic housing with an LC duplex receptacle. This receptacle fits into an RJ45 form factor outline. The 10-pin package and pinout conform to a multisource transceiver agreement. The transmitter features differential PECL logic level data inputs and a TTL logic level disable input. The receiver features differential PECL logic level data and a PECL logic level signal-detect output for the 1417G4A, and a TTL logic level signal-detect output for the 1417H4A.