BQ2201

The BQ2201 SRAM Nonvolatile Controller Unit by BQ is a CMOS integrated circuit that enables the conversion of standard CMOS SRAM into nonvolatile read/write memory. It is designed for 3-volt battery-backup applications, offering essential features like power monitoring and switching.

A key function of the BQ2201 is its write-protect control. A precision comparator monitors the 5V VCC input for out-of-tolerance conditions. When such a condition is detected, a conditioned chip-enable output is forced inactive, write-protecting any standard CMOS SRAM. During a power failure, the external SRAM is switched from the VCC supply to one of two 3V backup supplies. Upon subsequent power-up, the SRAM remains write-protected until a power-valid condition is established.

This controller boasts a chip-enable propagation delay of less than 10ns, making it footprint and timing compatible with industry standards. The power-fail detection threshold can be selected for 5% or 10% supply operation, occurring typically at 4.62V or 4.37V respectively. The operating temperature range is from -40°C to 85°C.

The BQ2201 is available in packages such as 8-Pin Narrow DIP, 16-Pin SOIC, and SOIC (D). It is suitable for applications requiring reliable data retention during power interruptions.