Microchip Technology 25CS640 64-Kbit SPI Serial EEPROMs

Microchip Technology 25CS640 64-Kbit SPI Serial EEPROMs provide 64Kbits of Serial EEPROM utilizing the Serial Peripheral Interface (SPI) compatible bus. The devices are organized as 8192 bytes of 8-bits each (8-Kbyte). The Microchip Technology 25CS640 EEPROMs are optimized for use in consumer and industrial applications where reliable and dependable nonvolatile memory storage is essential. The 25CS640 operates across a broad voltage range (1.7V to 5.5V). 25CS640 features a nonvolatile Security register independent of the 64-Kbit main memory array. The first half of the Security register is read-only and contains a factory-programmed, globally unique, 128-bit serial number in the first 16-bytes. The 128-bit read-only serial number is followed by an additional 32 bytes of user-programmable EEPROM.

The 25CS640 features a configurable write protection scheme, which allows the user to select Legacy Write Protection mode or Enhanced Write Protection mode. To protect against brown-out events, an undervoltage lockout detection circuit inhibits all write sequences when the V_CC supply voltage drops below the set voltage level. The voltage level is configurable via the Undervoltage Lockout Detection (UVLO) register. The 25CS640 utilizes a built-in Error Correction Code (ECC) scheme for added reliability.

The Microchip 25CS640 features an Identification register that contains identification information that can be read from the device. This enables the application to electronically query and identify the 25CS640 while it is in the system. The type of information that can be read from the
device includes the JEDEC® defined Manufacturer ID, the vendor-specific Device ID, and the vendor-specific Extended Device Information (EDI).

Features

64-Kbit Serial EEPROM
- 8192 x 8-bit organization
- Page size of 32-bytes
- Byte or sequential reads
- Byte or page writes
- Self-timed write cycle (4ms maximum)
Security register
- Preprogrammed 128-bit serial number
- 32-byte user-programmable, lockable ID page
Built-in Error Correction Code (ECC) logic, ECC status bit via the STATUS register
Undervoltage lockout detection
JEDEC® SPI manufacturer read ID support
High-speed clock frequency
- 20MHz at V_CC ≥ 4.5V
- 10MHz at V_CC ≥ 2.5V
- 5MHz at V_CC ≥ 1.7V
Legacy write protection mode, block protection functionality (quarter, half, or entire memory array)

Enhanced write protection mode
- User-definable memory partitions
- Each partition can be set independently and has unique protection behavior
Low-power CMOS technology
- 1.7V to 5.5V voltage range
- 5.0mA write current at 5.5V, 20MHz
- 3.0mA read current at 4.5V, 10MHz
- 1.0µA standby current at 5.5V (I-Temp.)
High reliability
- More than one million erase/write cycles
- Built-in ECC logic for increased reliability
- >200 years of data retention
- >4000V ESD protection
8-Lead MSOP, 8-Lead SOIC, 8-Lead TSSOP, and 8-Pad UDFN package options
Temperature ranges
- Industrial (I): -40°C to +85°C
- Extended (E): -40°C to +125°C
- Extended (H): -40°C to +150°C