RX-8803LC Real-Time Clock Modules Epson Timing RX-8803LC Real-Time Clock Modules offer a 1.6V to 5.5V interface voltage range and a built-in 32.7kHz crystal unit. RX-8803LC modules feature high stability, register compatibility with RX-8801, and a time synchronize function with 1PPS signal input. Epson Timing RX-8803LC Real-Time Clock Modules have an I2C-Bus interface type and various functions, including a full calendar, alarm, timer, and EVIN input.