描述 Description

The AT34C02B provides 2048 bits of serial electrically-erasable and programmable read only memory (EEPROM) organized as 256 words of 8 bits each. The first-half of the device incorporates a permanent and a reversible software write protection feature while hardware write protection for the entire array is available via an external pin. Once the permanent software write protection is enabled, by sending a special command to the device, it cannot be reversed. However, the reversible software write protection is enabled and can be reversed by sending a special command. The hard ware write protection is controlled with the WP pin and can be used to protect the entire array, whether or not the software write protection has been enabled. This allows the user to protect none, first-half, or all of the array depending on the application. The device is optimized for use in many industrial and commercial applications where low-power and low-voltage operations are essential. The AT34C02B is available in space saving 8-lead JEDEC SOIC, 8-lead Ultra Thin Mini-MAP (MLP 2x3), 8-lead TSSOP, and 8-ball dBGA2 packages and is accessed via a Two-wire serial interface. It is available in 1.7V (1.7V to 3.6V).

特性 Features

? Permanent and Reversible Software Write Protection for the First-half of the Array

– Software Procedure to Verify Write Protect Status

? Hardware Write Protection for the Entire Array

? Low-voltage and Standard-voltage Operation

– 1.7 (VCC = 1.7V to 3.6V)

? Internally Organized 256 x 8

? Two-wire Serial Interface

? Schmitt Trigger, Filtered Inputs for Noise Suppression

? Bidirectional Data Transfer Protocol

? 100 kHz (1.7V) and 400 kHz (2.7V and 3.6V) Compatibility

? 16-byte Page Write Modes

? Partial Page Writes Are Allowed

? Self-timed Write Cycle (5 ms max)

? High-reliability

– Endurance: 1 Million Write CycleLButtons

– Data Retention: 100 Years

? 8-lead JEDEC SOIC, 8-lead Ultra Thin Mini-MAP (MLP 2x3), 8-lead TSSOP, and 8-ball dBGA2 Packages