ISL59420EVAL1

The ISL59420EVAL1 evaluation board contains all the circuitry needed to characterize critical performance parameters of the ISL59420 single 2:1 multiplexing amplifier, over a variety of applications. The ISL59420 is a single-output, gain-selectable 2:1 MUX amp. The unity-gain bandwidth is 400MHz for this IC. It contains a common set of logic inputs for channel selection (S), three-state output control (HIZ), and an enable control input that powers down the device (EN).

The evaluation board circuit and layout is optimized for either 50Ω or 75Ω terminations, and implements a basic single 2:1 video MUX amp. The board is supplied with 75Ω input signal terminations and a 75Ω back-termination resistor on each of the three outputs, making it suitable for driving video cable. The user has the option of replacing the 75Ω resistors with 50Ω resistors for other applications. The control lines contain 50Ω resistors to match the 50Ω output impedance of high-speed pulse generators. Control line termination resistors are recommended for rise and fall times under 10ns to minimize unwanted transients. If DC is used for the control logic, the resistors may be removed, or the applied DC voltage can be reduced to 2.5V to reduce the dissipation in the termination resistor.