DS1200 DS1200 Serial RAM Chip FEATURES PIN ASSIGNMENT • 1024 bits of read/write memory • Low data retention current for battery backup applications • 4 million bits/second data rate VCC 1 10 NC RST 2 DQ CLK • Single byte or multiple byte data transfer capability NC 8 GND 4 7 5 6 GND • No restrictions on the number of write cycles NC VBAT 10-Pin DIP (300 MIL) See Mech. Drawings Section • Low-power CMOS circuitry • Applications include: – – – – – – – 9 3 software authorization computer identification system access control secure personnel areas calibration automatic system setup traveling work record VCC 1 16 NC 2 15 NC NC RST 3 DQ NC 4 5 14 13 NC GND 12 NC CLK 6 NC GND 7 11 10 8 9 NC NC VBAT 16-Pin SOIC (300 MIL) See Mech. Drawings Section PIN DESCRIPTION VCC RST DQ CLK GND VBAT NC – – – – – – – +5 Volts RESET Data Input/Output Clock Ground Battery (+) No Connection DESCRIPTION The DS1200 Serial RAM Chip is a miniature read/write memory which can randomly access individual 8-bit strings (bytes) or sequentially access the entire 1024-bit contents (burst). Interface cost to a microprocessor is minimized by on-chip circuitry which permits data transfers with only three signals: CLOCK, RST, and DATA INPUT/OUTPUT. should be used to size the external battery for the required data retention time. If nonvolatility is not required the VBAT pin should be grounded. For a complete description of operating conditions, electrical characteristics, bus timing, and signal descriptions other than VBAT, see the DS1201 Electronic Tag 1024-Bit data sheet. Nonvolatility can be achieved by connecting a battery of 2 to 4 volts at the battery input VBAT. A load of 0.5 µA 030598 1/1