AT25128B/AT25256B SPI Automotive Temperature Serial EEPROM 128 Kbits (16,384 x 8) and 256 Kbits (32,768 x 8) Features Serial Peripheral Interface (SPI) Compatible Supports SPI Modes 0 (0,0) and 3 (1,1): Data sheet describes mode 0 operation Low-Voltage and Medium-Voltage Operation: Grade 1, V = 2.5V to 5.5V CC Grade 3, V = 1.7V to 5.5V CC Extended Temperature Range (Grade 1 and Grade 3 as defined in AEC-Q100): Grade 1 Temperature Range: -40C to +125C Grade 3 Temperature Range: -40C to +85C 5 MHz Clock Rate (5V) 64 Byte Page Mode Block Write Protection: Protect 1/4, 1/2 or entire array Write-Protect (WP) Pin and Write Disable Instructions for Both Hardware and Software Data Protection Self-Timed Write Cycle within 5 ms Maximum Automotive AEC-Q100 Qualified High Reliability: Endurance: 1,000,000 write cycles Data retention: 100 years Green (Lead-free/Halide-free/RoHS Compliant) Package Options Packages 8-Lead SOIC, 8-Lead TSSOP and 8-Pad UDFN Datasheet DS20006269B-page 1 2020 Microchip Technology Inc. AT25128B/AT25256B Table of Contents Features......................................................................................................................................................... 1 Packages........................................................................................................................................................1 1. Package Types (not to scale)..................................................................................................................4 2. Pin Description........................................................................................................................................5 2.1. Chip Select (CS)...........................................................................................................................5 2.2. Serial Data Output (SO)............................................................................................................... 5 2.3. Write-Protect (WP)....................................................................................................................... 5 2.4. Ground (GND)..............................................................................................................................5 2.5. Serial Data Input (SI)....................................................................................................................6 2.6. Serial Data Clock (SCK)...............................................................................................................6 2.7. Suspend Serial Input (HOLD).......................................................................................................6 2.8. Device Power Supply (V )......................................................................................................... 6 CC 3. Description.............................................................................................................................................. 7 3.1. SPI Bus Master Connections to Serial EEPROMs.......................................................................7 3.2. Block Diagram..............................................................................................................................8 4. Electrical Characteristics.........................................................................................................................9 4.1. Absolute Maximum Ratings..........................................................................................................9 4.2. DC and AC Operating Range.......................................................................................................9 4.3. DC Characteristics....................................................................................................................... 9 4.4. AC Characteristics......................................................................................................................10 4.5. SPI Synchronous Data Timing....................................................................................................11 4.6. Electrical Specifications..............................................................................................................11 5. Device Operation.................................................................................................................................. 13 5.1. Interfacing the AT25128B/AT25256B on the SPI Bus................................................................ 13 5.2. Device Opcodes.........................................................................................................................14 5.3. Hold Function............................................................................................................................. 14 5.4. Write Protection..........................................................................................................................15 6. Device Commands and Addressing......................................................................................................16 6.1. STATUS Register Bit Definition and Function............................................................................ 16 6.2. Read STATUS Register (RDSR)..................................................................................................17 6.3. Write Enable (WREN) and Write Disable (WRDI)......................................................................... 17 6.4. Write STATUS Register (WRSR)..................................................................................................18 7. Read Sequence.................................................................................................................................... 21 8. Write Sequence.....................................................................................................................................22 8.1. Byte Write...................................................................................................................................22 8.2. Page Write..................................................................................................................................22 8.3. Polling Routine........................................................................................................................... 23 9. Packaging Information.......................................................................................................................... 24 DS20006269B-page 2 Datasheet 2020 Microchip Technology Inc.