DS1315S-33

Overview

The DS1315S-33 is a Phantom Time Chip combining a CMOS timekeeper and nonvolatile memory controller in a 16-pin SO package. It tracks hundredths of seconds, seconds, minutes, hours, day, date, month, and year with automatic leap year correction valid to 2100. Operating at +3.3V or +5V, it interfaces via serial pattern recognition without requiring address space. The device provides battery backup for external SRAM using BAT1/BAT2 inputs and includes power-fail detection and write protection. It supports industrial temperature ranges and operates within a full ±10% VCC range.

Feature Summary

• Combines real-time clock and nonvolatile memory controller
• Automatic leap year correction valid up to 2100
• Serial interface requires no address space allocation
• Supports redundant battery attachment for high reliability

Applications

• Systems requiring nonvolatile RAM backup
• High-reliability applications with redundant batteries
• Embedded systems needing precise timekeeping without CPU overhead

Procurement Notes

Verify the specific suffix 'S' indicates the 16-pin SO package. Confirm the '-33' suffix specifies the 3.3V operating voltage variant. Check for lead-free status indicated by '+' if required. Ensure the industrial temperature grade ('N') is selected if operation below 0°C is needed, as the base part number may imply commercial range.

Selection Notes

Select this component when a serial RTC that does not consume system address space is required. Choose the -33 variant for 3.3V logic systems. Consider the SN-33+ version for industrial temperature requirements (-40°C to +85°C). Ensure the external SRAM voltage matches the VCCO output capability. Verify crystal load capacitance requirements (6 pF) for timing accuracy.

Part Context

The DS1315 series serves as a phantom time chip, allowing timekeeping without dedicated bus cycles. The S-33 variant specifically denotes the 16-pin Small Outline package operating at 3.3V. It is part of a broader family including PDIP and TSSOP options with varying voltage and temperature ratings.

Replacement Considerations

Direct pin-compatible replacements include other DS1315 variants such as DS1315SN-33+ for industrial temperature or DS1315EN-33+ for TSSOP packaging. Cross-family RTCs require interface redesign due to the unique serial pattern recognition protocol.