RX4901CE and RX8901CE Real-Time Clocks

Epson’s RX8901CE and RX4901CE are versatile and high-precision real-time clock modules with low power consumption ideal for smart meters, security equipment, and smart lighting applications. The integrated event system with up to three event inputs can be used to detect events and record their timestamp while the MCU remains in sleep mode, reducing system power consumption for longer battery life. The modules can record timestamps for 32 events in either FIFO or direct mode. They consume just 240 nA from a 3 V supply and feature a built-in power supply switching circuit that eliminates the need for external diodes and their losses. The modules offer time resolution down to 1/1024^th of a second and are highly stable across their entire operating temperature range. The RX8901CE has an I²C interface, while the RX4901CE is available with a 3- or 4-wire SPI.

Features and Benefits

• High precision time keeping over a wide temperature range (-40°C to +105°C)
• Built-in digital temperature compensation (DTXCO) technology
• Low current consumption 240 nA (typ)
• Selectable output frequency 32.768 kHz, 1024 Hz, or 1 Hz clock
• Supports up to three event pins and 32 time stamps capable of detecting up to three individual events at a time
• Time resolution from 1/1024 sec to 32 years
• Supports I²C or SPI communications
• Package size 3.2 mm x 2.5 mm x 1.0 mm (CE package)