4 and 1/2 digit smart voltmeter circuit

The circuit of a 4% smart voltmeter composed of MAX1494 is shown in Figure 5-30. When using a single power supply,
a decoupling circuit must be added to the analog power input terminal and the digital power input terminal. The power decoupling circuit consists of a small inductor L and a capacitor CZ-C6. L is
a magnetic bead made of ferrite material, which can also be replaced by a small resistor of 100. Ci and G are used to filter out the interference voltage at the analog input terminal. Through resistor R. , R2 can set
the value voltage of low voltage indication.
    When designing a printed circuit board, pay attention to the following things:
    First? Try to avoid wiring near the common digital ground line , because this will cause the noise voltage to increase; laying
the wiring close to the common analog ground line can minimize the noise voltage.
    Second, the clock signal line should be as short as possible and must not cross with other leads to avoid interference.
    Third, digital signals and analog signals should be routed separately to avoid crossover.