IDT5991A

NOTE:
1. Stresses beyond those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolutemaximum- rated conditions for extended periods may affect device reliability.

The IDT5991A is a high fanout PLL based clock driver intended for high performance computing and data-communications applications. A key feature of the programmable skew is the ability of outputs to lead or lag the REF input signal. The IDT5991A has eight programmable skew outputs in four banks of 2. Skew is controlled by 3-level input signals that may be hard-wired to appropriate HIGH-MID-LOW levels.

The IDT5991A maintains Cypress CY7B991 compatibility while providing two additional features: Synchronous Output Enable (GND/sOE), and Positive/Negative Edge Synchronization (VCCQ/PE). When the GND/ sOE pin is held low, all the outputs are synchronously enabled (IDT5991A compatibility). However, if GND/sOE is held high, all the outputs except 3Q0 and 3Q1 are synchronously disabled.

Furthermore, when the VCCQ/PE is held high, all the outputs are synchronized with the positive edge of the REF clock input (IDT5991A compatibility). When VCCQ/PE is held low, all the outputs are synchronized with the negative edge of REF.