DESCRIPTION
The Quad T1 and E1 Transceiver MCMs offer a high density packaging arrangement for the DS21352/DS21552 T1 Single-Chip Transceivers and the DS21354/DS21554 E1 Single-Chip Transceivers. Four silicon die of one of these devices is packaged in a Multi-Chip Module (MCM) with the electrical connections as shown in Figure 1. All of the functions available on the DS21352/DS21552 and DS21354/DS21554 are also available in the MCM packaged version however in order to minimize package size, some signals have been deleted. These differences are detailed in Table 1.

FEATURES
• Four (4) Completely Independent T1 or E1 Transceivers In One Small 27mm x 27mm Package
• Each Transceiver Contains a Short & Long Haul Line Interface Plus a Full Featured Framer with Alarm Detection/Generation, Elastic Stores, Hardware Based Signaling Support, Per DS0 Channel Control and HDLC Controller
• Each Multi-Chip Module (MCM) Contains Four Die of:
   DS21352 (DS21Q352)
   DS21552 (DS21Q552)
   DS21354 (DS21Q354)
   DS21554 (DS21Q554)
• Selection Guide:
        Supply  Device
   T1 3.3V      DS21Q352
   T1 5V         DS21Q552
   E1 3.3V      DS21Q354
   E1 5V         DS21Q554
• See the Specific DS21352/DS21552 and DS21354/DS21554 Data Sheets for Details on their Feature Set and Operation
• All Four T1 or E1 Transceivers Can be Concatenated into a Single 8.192MHz Backplane Data Stream
• IEEE 1149.1 JTAG-Boundary Scan Architecture
• DS21Q352/DS21Q552 and DS21Q354/DS21Q554 are Pin Compatible to Allow the Same Footprint to Support T1 and E1 Applications
• 256–lead MCM BGA package (27mm X 27mm)
• Low Power 5V CMOS or Low Power 3.3V CMOS with 5V Tolerant Input & Outputs