GENERAL DESCRIPTION
The W25B40 / W25B40A is a 4Mb (512KB) Serial Flash Memory with erasable sectors that allows for boot code and parameter storage. The W25B40 / W25B40A is packaged in an 8-pin SOIC 150-mil and is compatible with the standard W25P40 specification with the following exceptions.
FEATURES
• W25B40 / W25B40A 4M-bit Serial Flash
– 4M-bit /512K-byte (524,288)
– 256-bytes per programmable page
• Compatible with W25P40 with special
features
– Small Boot and Parameter Sectors
– Write protection of Boot/Parameter area
• Variable Sector Sizes for Boot Code and
Parameter Storage
– Seven sectors of 64KB
– One sector each of 32KB, 16Kb and 8KB
– Two sectors of 4KB
– Bottom Boot organization (standard)
– Top Boot organization (special order)
• 4-pin SPI Serial Interface
– Clock, Chip Select, Data In, Data Out
– Easily interfaces to popular microcontrollers
– Compatible with SPI Modes 0 and 3
– Optional Hold function for SPI flexibility
• Low Power Consumption, Wide
Temperature Range
– Single 2.7 to 3.6V supply
– 5mA active current, <1µA Power-down
– -40° to +85°C operating range
• Fast and Flexible Serial Data Access
– Clock operation to 40MHz
– Byte-addressable Read and Program
– Auto-increment Read capability
– Manufacturer and Device ID
• Programming Features
– Page program up to 256 bytes 2mS
– Sector Erase 120mS to 650mS
– Chip erase 5.5 seconds
– 100,000 erase/write cycles
– Twenty-year data retention
• Software and Hardware Write
Protection
– Write-Protect all or portion of memory
– Enable/Disable protection with /WP pin
• SOIC Compatible Packaging
– Tiny 8-pin SOIC 150mil
• Ideal for systems with limited pins,
space, and power
– Controller-based serial code-download
– µC systems storing data, text or voice
– Battery-operated and portable product