DESCRIPTION

The X24645 is a CMOS 65,536-bit serial E2PROM, internally organized 8192 x 8. The X24645 features a serial interface and software protocol allowing operation on a simple two wire bus.

Two device select inputs (S1, S2) allow up to four devices to share a common two wire bus.

A Write Protect Register at the highest address location, 1FFFh, provides three new write protection features: Software Write Protect, Block Write Protect, and Hardware Write Protect. The Software Write Protect feature prevents any nonvolatile writes to the X24645 until the WEL bit in the write protect register is set. The Block Write Protection feature allows the user to individually write protect four blocks of the array by programming two bits in the write protect register. The Programmable Hardware Write Protect feature allows the user to install the X24645 with WP tied to VCC, program the entire memory array in place, and then enable the hardware write protection by programming a WPEN bit in the write protect register. After this, selected blocks of the array, including the write protect register itself, are permanently write protected, as long as WP remains HIGH.

FEATURES

• 2.7V to 5.5V Power Supply

• Low Power CMOS

   —Active Read Current Less Than 1mA

   —Active Write Current Less Than 3mA

   —Standby Current Less Than 1µA

• Internally Organized 8192 x 8

• New Programmable Block Lock Protection

   —Software Write Protection

   —Programmable hardware Write Protect

• Block Lock (0, 1/4, 1/2, or all of the E2PROM array)

• 2 Wire Serial Interface

• Bidirectional Data Transfer Protocol

• 32 Byte Page Write Mode

   —Minimizes Total Write Time Per Byte

• Self Timed Write Cycle

   —Typical Write Cycle Time of 5ms

• High Reliability

   —Endurance: 100,000 Cycles

   —Data Retention: 100 Years

• Available Packages

   —8-Lead PDIP

   —8-Lead SOIC (JEDEC)

   —14-Lead SOIC (JEDEC)

   —20-Lead TSSOP