DS1501YS

Real Time Clock Overview

The DS1501YS is a Y2K-compliant real-time clock/calendar IC manufactured by Analog Devices Inc./Maxim Integrated. It features a parallel interface, 256 bytes of battery-backed NV SRAM, and operates within a voltage range of 4.5V to 5.5V for VCC and 2.5V to 3.7V for battery backup. The device provides timekeeping in HH:MM:SS (24-hour) format with automatic leap-year compensation up to the year 2100. It includes an RTC alarm, watchdog timer, power-on reset, and battery monitoring capabilities. The component is housed in a 28-SOIC package and supports industrial operating temperatures from 0°C to +70°C.

Real Time Clock Feature Summary

• Y2K-Compliant RTC with BCD-coded century, year, month, date, day, hours, minutes, and seconds
• 256 Bytes Battery-Backed Non-Volatile SRAM
• Programmable Watchdog Timer and Day-of-Week/Date Alarm
• Precision Power-On Reset and Battery Voltage-Level Indicator Flags

Real Time Clock Applications

• Remote Systems
• Battery-Backed Systems
• Telecom Switches
• Office Equipment
• Consumer Electronics

Real Time Clock Procurement Notes

Verify the specific suffix 'YS' against official manufacturer documentation to confirm pinout compatibility and electrical specifications relative to other variants like DS1501Y or DS1501WE. Confirm RoHS compliance status and lead-free designation as indicated by the '+' symbol in ordering information. Check current availability status through authorized distributors, as this part may be subject to limited supply or end-of-life restrictions.

Real Time Clock Selection Notes

Select the DS1501YS when a parallel interface is required for direct register access without serial protocol overhead. Ensure the system design accommodates the 28-pin SOIC footprint and provides appropriate pull-up resistors for open-drain outputs like IRQ, PWR, and RST. Verify that the external crystal matches the specified load capacitance (6pF or 12.5pF) via the CS bit configuration for optimal accuracy.

Real Time Clock Part Context

The DS1501YS belongs to the DS1501 family of real-time clocks, which are designed for applications requiring precise timekeeping and data retention during power failures. This family integrates RTC functions with non-volatile memory, simplifying system design by reducing the component count compared to discrete solutions. The 'YS' suffix typically denotes a specific package variant within this series, distinct from DIP or TSOP options.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers include DS1501Y, DS1501WE, DS1501WEN, DS1511, MAX31341C, MAX31343, MAX31341B, DS1308, DS3232M, DS1344, DS1343, DS3234, DS3232, DS12CR887, DS12R885, DS1511, DS1338, DS1338C, DS1244, DS1685, DS1687, DS1744, DS12885, DS12887, DS12887A, DS12C887, DS12C887A, DS1305, DS17285, DS17287, DS17485, DS17487, DS17885, DS17887, DS1248, DS1251, DS1306, DS1678, DS1747, DS1554, DS1556, and DS1557.