DESCRIPTION
The DS1330W 3.3V 256K Nonvolatile SRAM is a 262,144–bit, fully static, nonvolatile SRAM organized as 32,768 words by eight bits. Each NV SRAM has a self–contained lithium energy source and control circuitry which constantly monitors VCC for an out–of–tolerance condition. When such a condition occurs, the lithium energy source is automatically switched on and write protection is unconditionally enabled to prevent data corruption. Additionally, the DS1330W has dedicated circuitry for monitoring the status of VCC and the status of the internal lithium battery. DS1330W devices in the PowerCap Module package are directly surface mountable and are normally paired with a DS9034PC PowerCap to form a complete Nonvolatile SRAM module. The devices can be used in place of 32K x 8 SRAM, EEPROM or Flash components.

FEATURES
• 10 years minimum data retention in the absence of external power
• Data is automatically protected during power loss
• Power supply monitor resets processor when VCC power loss occurs and holds processor in reset during VCC ramp–up
• Battery monitor checks remaining capacity daily
• Read and write access times as fast as 150 ns
• Unlimited write cycle endurance
• Typical standby current 50 µA
• Upgrade for 32K x 8 SRAM, EEPROM or Flash
• Lithium battery is electrically disconnected to retain freshness until power is applied for the first time
• Optional industrial temperature range of –40°C to +85°C, designated IND
• New PowerCap Module (PCM) package
   – Directly surface–mountable module
   – Replaceable snap–on PowerCap provides lithium backup battery
   – Standardized pinout for all nonvolatile SRAM products
   – Detachment feature on PowerCap allows easy removal using a regular screwdriver