NV-SRAM

General description

The HMN4M8D Nonvolatile SRAM is a 33,554,432-bit static RAM organized as 4,194,304 words by 8 bits. The HMN4M8D has a self-contained lithium energy source provide reliable non-volatility coupled with the unlimited write cycles of standard SRAM and integral control circuitry which constantly monitors the single 5V supply for an out-of-tolerance condition. When such a condition occurs, the lithium energy source is automatically switched on to sustain the memory until after V_CC returns valid and write protection is unconditionally enabled to prevent garbled data. In addition the SRAM is unconditionally write-protected to prevent an inadvertent write operation. At this time the integral energy source is switched on to sustain the memory until after V_CC returns valid. The HMN2M8D uses extremely low standby current CMOS SRAM's, coupled with small lithium coin cells to provide non-volatility without long write-cycle times and the write-cycle limitations associated with EEPROM.

Features

• Part identification
• HMN4M8D 32Mbit, 40Pin , DIP package
• Access time: 55,70ns
• High-density design: 32MBit design
• Battery internally isolated until power is applied
• Industry-standard 36-pin 4,096K x 8pinout
• Low-power CMOS
• Unlimited writes cycles
• Data retention in the absence of V_CC
• 10-years minimum data retention in absence of power
• Automatic write-protection during power-up/power-down cycles
• Data is automatically protected during power loss conventional SRAM operation: unlimited write cycle.