特性
- REF is 5V tolerant
- 4 pairs of programmable skew outputs
- Low skew: 200ps same pair, 250ps all outputs
- Selectable positive or negative edge synchronization:Excellent for DSP applications
- Synchronous output enable
- Output frequency: 3.75MHz to 85MHz
- 2x, 4x, 1/2, and 1/4 outputs
- 3 skew grades:IDT5V991A-2: tSKEW0<250psIDT5V991A-5: tSKEW0<500psIDT5V991A-7: tSKEW0<750ps
- 3-level inputs for skew and PLL range control
- PLL bypass for DC testing
- External feedback, internal loop filter
- 12mA balanced drive outputs
- Low Jitter: <200ps peak-to-peak
- Available in 32-pin PLCC Package
描述
The 5V991A is a high fanout 3.3V PLL based clock driver intended for high performance computing and data-communications applications. Akey feature of the programmable skew is the ability of outputs to lead or lag the REF input signal. The 5V991A 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. When the GND/sOE pin is held low, all the outputs are synchronously enabled. 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. When VCCQ/PE is held low, all the outputs are synchronized with the negative edge of REF. Both devices have LVTTL outputs with 12mA balanced drive outputs.
