General description

The PCF8593 is a CMOS1 clock and calendar circuit, optimized for low power consumption. Addresses and data are transferred serially via the two-line bidirectional I2C-bus. The built-in word address register is incremented automatically after each written or read data byte. The built-in 32.768 kHz oscillator circuit and the first 8 bytes of the RAM are used for the clock, calendar, and counter functions. The next 8 bytes can be

programmed as alarm registers or used as free RAM space.

Features and benefits

„ I2C-bus interface operating supply voltage: 2.5 V to 6.0 V

„ Clock operating supply voltage 1.0 V to 6.0 V at 0 °C to +70 °C

„ 8 bytes scratchpad RAM (when alarm not used)

„ Data retention voltage: 1.0 V to 6.0 V

„ External RESET input resets I2C interface only

„ Operating current (at fSCL = 0 Hz, 32 kHz time base, VDD = 2.0 V): typical 1 μA

„ Clock function with four year calendar

„ Universal timer with alarm and overflow indication

„ 24 hour or 12 hour format

„ 32.768 kHz or 50 Hz time base

„ Serial input and output bus (I2C-bus)

„ Automatic word address incrementing

„ Programmable alarm, timer, and interrupt function

„ Space-saving SO8 package available

„ Slave addresses: A3h for reading, A2h for writing