The AD53020 is a four-channel delay line designed for use in automatic test equipment and digital logic systems. High speed bipolar transistors and a 44-lead plastic PLCC package with internal heat spreader provide high frequency performance at a minimum of space, cost and power dissipation. Featuring full pin compatibility and functional equivalence to the BT624, the AD53020 offers independent analog control of positive and negative edges with five delay ranges. The AD53020 offers attractive performance with optimized power dissipation and linear delay vs. program voltage control. This device is also very stable over operating conditions and has very low jitter. Digital inputs are ECL compatible. They can either be provided independently for each channel (IN1, IN1 through IN4, IN4 ), or fanned out to all channels from Channel 2 (IN2, IN2). The choice of these two options is made by setting the DRVMODE input, with ECL Logic 0 providing four independent channels, and ECL Logic 1 enabling a logical OR function between each channel and the Channel Number 2. For maximum timing accuracy, differential signals are recommended for use with the digital inputs. However, single-ended operation is also supported and it is facilitated through the use of the VBB midpoint level generated on-chip. To make use of this feature, connect the VBB output to the inverting input of each channel. It is also advisable, when using the VBB output, to decouple this signal with a 0.1 F ceramic capacitor to ground. The outputs of the AD53020 are ECL compatible and should be terminated by 50 to 2.0 V at the inputs of the gates they drive. |