DESCRIPTION

The DS1610 is a low-power CMOS circuit which solves the application problems of converting CMOS RAMS into nonvolatile memories. In addition the device has the ability to unconditionally write protect blocks of memory so that inadvertent write cycles do not corrupt program and special data space. The power supply incoming voltage at the VCCI input pin is constantly monitored for an out-of-tolerance condition. When such a condition is detected, both the chip enable and write enable outputs are inhibited to protect stored data. The battery inputs are used to supply VCCO with power when VCCI is less than the battery input voltages. Special circuitry uses a low leakage CMOS process which affords precise voltage detection at extremely low current consumption. By combining the DS1610 Partitioned NV Controller chip with a CMOS memory and batteries, nonvolatile RAM operation can be achieved.

FEATURES

■ Converts CMOS RAMs into nonvolatile memories

■ SOIC version is pin-compatible with the Dallas Semiconductor DS1210 NV Controller

■ Unconditionally write protects all of memory when VCC is out of tolerance

■ Write protects selected blocks of memory regardless of VCC status when programmed

■ Automatically switches to battery backup supply when power-fail occurs

■ Provides for multiple batteries

■ Consumes less than 100 nA of battery current

■ Test battery on power-up by inhibiting the second memory cycle

■ Optional 5 or 10 power-fail detection

■ 16-pin DIP or 16-pin SOIC surface-mount package

■ Low forward voltage drop on the VCC switch with currents of up to 150 mA

■ Optional industrial temperature range of -40°C to +85°C