The Microchip Technology Inc. 25XX040A* is a 4 Kbit
Serial Electrically Erasable Programmable Read-Only
Memory (EEPROM). The memory is accessed via a
simple Serial Peripheral Interface (SPI) compatible
serial bus. The bus signals required are a clock input
(SCK) plus separate data in (SI) and data out (SO)
lines. Access to the device is controlled through a Chip
Select (CS) input.
Communication to the device can be paused via the
hold pin (HOLD). While the device is paused, transitions
on its inputs will be ignored, with the exception of
Chip Select, allowing the host to service higher priority
interrupts.
The 25XX040A is available in standard packages
including 8-lead PDIP and SOIC, and advanced
packages including 8-lead MSOP, 8-lead TSSOP
and rotated TSSOP, 8-lead 2x3 DFN, and 6-lead
SOT-23.