PCF8570 Datasheet PDF - NXP Semiconductors.

GENERAL DESCRIPTION
The PCF8570 is a low power static CMOS RAM, organized as 256 words by 8-bits.
Addresses and data are transferred serially via a two-line bidirectional bus (I2C-bus). The built-in word address register is incremented automatically after each written or read data byte. Three address pins, A0, A1 and A2 are used to define the hardware address, allowing the use of up to 8 devices connected to the bus without additional hardware.

FEATURES
• Operating supply voltage 2.5 to 6.0 V
• Low data retention voltage; minimum 1.0 V
• Low standby current; maximum 15 µA
• Power-saving mode; typical 50 nA
• Serial input/output bus (I2C-bus)
• Address by 3 hardware address pins
• Automatic word address incrementing
• Available in DIP8 and SO8 packages.
 
APPLICATIONS
• Telephony:
    – RAM expansion for stored numbers in repertory dialling (e.g. PCD33xxA applications)
• General purpose RAM for applications requiring extremely low current and low-voltage RAM retention, such as battery or capacitor-backed.
• Radio, television and video cassette recorder:
    – channel presets
• General purpose:
    – RAM expansion for the microcontroller families PCD33xxA, PCF84CxxxA, P80CLxxx and most other microcontrollers.