DS1747WP-120IND

Real Time Clock Overview

The DS1747WP-120IND is a Y2K-compliant, nonvolatile timekeeping RAM integrating a real-time clock (RTC), 512k x 8 static RAM, crystal, and lithium energy source. It operates at a supply voltage of 3.3V with an industrial temperature range of -40°C to +85°C. The device uses a parallel interface and features a 34-pin PowerCap module package. RTC registers are double-buffered and reside in the top eight RAM locations, providing century, year, month, date, day, hours, minutes, and seconds data in BCD format. Automatic leap year compensation is valid up to the year 2100.

Real Time Clock Feature Summary

• Integrated NV SRAM, RTC, Crystal, Power-Fail Control Circuit, and Lithium Energy Source
• Y2K Compliant with Century Byte Register and Automatic Leap Year Compensation Valid to 2100
• Power-Fail Write Protection Allows for ±10% VCC Power-Supply Tolerance
• Lithium Energy Source Electrically Disconnected Until First Power Application

Real Time Clock Applications

• Industrial systems requiring precise timekeeping without external battery maintenance
• Equipment needing nonvolatile memory with integrated calendar functions
• Applications requiring high power-supply tolerance and automatic write protection

Real Time Clock Procurement Notes

Verify that the required PowerCap component (DS9034PCX+ or DS9034I-PCX+) is ordered separately, as it is not included with the DS1747WP-120IND module. Confirm the specific ordering suffix matches the desired temperature range and voltage specifications. Ensure compatibility with the target system's parallel bus timing requirements.

Real Time Clock Selection Notes

Select this model for applications requiring a 3.3V supply and industrial temperature operation (-40°C to +85°C). The PowerCap package allows surface-mount assembly before attaching the battery-containing PowerCap, protecting sensitive components from reflow heat. Ensure the design accommodates the separate mounting of the PowerCap module after the main board soldering process.

Real Time Clock Part Context

The DS1747 series includes variants with different supply voltages (5V and 3.3V) and packages (EDIP DIP and PowerCap). The WP suffix indicates the 3.3V PowerCap version. Other models like DS1747P-70IND use a 5V supply and may have different electrical characteristics. The series is pin-compatible across densities within the same package type.

Real Time Clock Replacement Considerations

Direct replacements include other DS1747 series parts with matching voltage and temperature ratings, such as DS1747WP-120+ for commercial temperature range. Verify package compatibility and ensure the substitute supports the required 3.3V operation and industrial temperature range if applicable.