The CMOS bq2205 SRAM non-volatile controller with reset provides all the necessary functions for converting one or two banks of standard CMOS SRAM into non-volatile read/write memory.
●A precision comparator monitors the 3.3-V VCC input for an out-of-tolerance condition. When out-of-tolerance is detected, the two conditioned chip-enable outputs are forced inactive to write-protect both banks of SRAM.
●Power for the external SRAMs, VOUT, is switched from the VCC supply to the battery-backup supply as VCC decays. On a subsequent power-up, the VOUT supply is automatically switched from the backup supply to the VCC supply. The external SRAMs are write-protected until a power-valid condition exists. The reset output provides power-fail and power-on resets for the system. During power-valid operation, the input decoder, A, selects one of two banks of SRAM.
● Power Monitoring and Switching for Non-Volatile Control of SRAMs
● Input Decoder Allows Control of 1 or 2 Banks of SRAM
● Write-Protect Control
● 3-V Primary Cell Input
● 3.3-V Operation
● Reset Output for System Power-On Reset
● Less than 20-ns Chip Enable Propagation Delay
● Small 16-Lead TSSOP Package
● APPLICATIONS
● NVSRAM Modules
● Point-of-Sale Systems
● Facsimile, Printers and Photocopiers
● Internet Appliances
● Servers
● Medical Instrumentation and Industrial Products
