The ICL7106 and ICL7107 are high performance, low power, 31/2 digit A/D converters including seven segment decoders , display drivers, a reference, and a clock.
The ICL7106 is designed to interface with a liquid crystal display (LCD) and includes a multiplexed backplane drive and the ICL7107 will directly drive an instrument size light emitting diode (LED) display.
Main features of ICL7106 and ICL7107 are : True Polarity at Zero for Precise Null Detection , 1pA Typical Input Current ,True Differential Input and Reference, Direct Display Drive - LCD ICL7106- LED lCL710 , Low Noise - Less Than 15μVP-P , On Chip Clock and Reference , Low Power Dissipation - Typically Less Than 10mW.
Using the ICL7106 and ICL7107 electronic schematic presented in this sheet you can make a simple and very useful digital voltmeter , using few external components .
As you can see in this schematic circuits you can make a digital voltmeter with a LED display or using a liquid crystal display .