DS1743

DS1743/DS1743P Y2KC Nonvolatile Timekeeping RAM www.dalsemi.com FEATURES Integrated NV SRAM, real time clock, crystal, powerfail control circuit and lithium energy source Clock registers are accessed identical to the static RAM. These registers are resident in the eight top RAM locations. Century byte register Totally nonvolatile with over 10 years of operation in the absence of power BCD coded century, year, month, date, day, hours, minutes, and seconds with automatic leap year compensation valid up to the year 2100 Battery voltage level indicator flag Power-fail write protection allows for ±10% VCC power supply tolerance Lithium energy source is electrically disconnected to retain freshness until power is applied for the first time DIP Module only – Standard JEDEC bytewide 8k x 8 static RAM pinout PowerCap Module Board only – Surface mountable package for direct connection to PowerCap containing battery and crystal – Replaceable battery (PowerCap) – Power-On Reset Output – Pin for pin compatible with other densities of DS174XP Timekeeping RAM PIN ASSIGNMENT NC A12 A7 A6 A5 A4 A3 A2 A1 A0 DQ0 DQ1 DQ2 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 VCC WE CE2 A8 A9 A11 OE A10 CE DQ7 DQ6 DQ5 DQ4 DQ3 28-Pin Encapsulated Package (700-mil Extended) NC NC NC RST VCC WE OE CE DQ7 DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 NC NC NC NC A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 ...