The MCP45HVX1 family of devices have dual power rails （analog and digital）。 The analog power rail allows high voltage on the resistor network terminal pins. The analog voltage range is determined by the V+ and V– voltages. The maximum analog voltage is +36V， while the operating analog output minimum specifications are specified from either 10V or 20V. As the analog supply voltage becomes smaller， the analog switch resistances increase， which affect certain performance specifications. The system can be implemented as dual rail （±18V） relative to the digital logic ground （DGND）。 The device also has a Write Latch （WLAT） function， which will inhibit the volatile Wiper register from being updated （latched） with the received data， until the WLAT pin is Low. This allows the application to specify a condition where the volatile Wiper register is updated （such as zero crossing）.