NE568A
DESCRIPTION
The NE568A is a monolithic phase-locked loop (PLL) which operates from 1Hz to frequencies in excess of 150MHz and features an extended supply voltage range and a lower temperature coefficient of the VCO center frequency in parison with its predecessor, the NE 568. The NE568A is function and pin-patible with the NE568, requiring only minor changes in peripheral circuitry (see Figure 3). Temperature pensation network is different, no resistor on Pin 12, needs to be grounded and Pin 13 has a 3.9kΩ resistor to ground. Timing cap, C2, is different and for 70MHz operation with temperature pensation network should be 16p F, not 34p F as was used in the NE568. The NE568A has the following improvements: ESD protected; extended VCC range from 4.5V to 5.5V; operating temperature range -55 to 125°C (see Signetics Military 568A data sheet); less layout sensitivity; and lower TC of VCO (center frequency). The integrated circuit consists of a limiting amplifier, a current-controlled...
