DS26504LN+

The DS26504LN+ from Analog Devices (Maxim Integrated) is a versatile Telecom IC designed as a Building-Integrated Timing-Supply (BITS) clock-recovery element and a basic T1/E1 transceiver. It is capable of recovering clocks from various synchronization interfaces including T1, E1, 64kHz composite clock (64KCC), and 6312kHz. In T1 and E1 modes, it can also recover the Synchronization Status Message (SSM).

The transmit portion of the DS26504LN+ can interface directly with T1, E1, or 64KCC synchronization interfaces and can source the SSM in T1 and E1 modes. This device facilitates translation between supported inbound and outbound synchronization clock rates. It accepts reference clocks such as 8kHz and 19.44MHz, and provides a dedicated output for a 6312kHz clock.

Key features include compliance with GR378 Composite Clock and G.703 synchronization standards for various interfaces. It supports standard T1/J1 (1.544MHz) and E1 (2.048MHz) interfaces, as well as CMI-coded T1/J1 and E1. The device offers crystal-less jitter attenuation with a bypass mode for T1 and E1 operation, and fully independent transmit and receive functionality. Internal software-selectable termination supports multiple impedance values (75Ω to 133Ω).

Controlled via a parallel, serial (SPI), or hardware controller port, the DS26504LN+ provides indications for Loss of Signal (LOS), Alarm Indication Signal (AIS), and Loss of Frame (LOF) through hardware output pins. It operates on a 3.3V supply with 5V tolerant inputs and outputs. The DS26504LN+ is supplied in a 64-LQFP package suitable for surface mounting.