This board is designed to demonstrate the LMH7324 quad
comparator with RSPECL outputs. It will facilitate the evaluation
of the LMH7324 configured as a window detector. The
board detects the level of the incoming signal and presents
the outcome in a 3-bit presentation. One bit indicates that the
signal is below the lowest window level, another bit indicates
that the signal is above the highest window level, and the third
bit indicates that the incoming signal is just between both set
levels. All three outputs are fed to SMA connectors mounted
at the edge of the board. The impedance of the output track
is 50Ω which makes it easy to connect these signals to any
scope or analyzer by the use of a 50Ω coaxial cable. Each
comparator of the LMH7324 has individual positive supplies
for the input and output circuits. The negative supply is common
for all input and output circuitry. This setup will work with
a supply of ±2.5V as a minimum supply, with the window voltage
centered at ground. If a setup with only one positive
supply voltage is used, jumper J1 (see Figure 7) has to be
placed between both positive supply connections. To examine
the possibility of two separate supplies for the input and
the output stage the jumper has to be removed and an extra
supply has to be connected.