DS1501WEN/T&R

Real Time Clock Overview

The DS1501WEN/T&R is a Y2K-compliant real-time clock/calendar IC manufactured by Analog Devices Inc./Maxim Integrated. It operates at +3.3V with an industrial temperature range of -40°C to +85°C and is housed in a 28-pin TSOP package. The device features a byte-wide parallel interface, 256 bytes of NV SRAM, and automatic leap-year compensation valid until 2100. Key electrical parameters include a standby current of 4mA (TTL) or 4mA (CMOS) at 3.3V, a battery voltage range of 2.5V to 3.7V, and a typical battery leakage current of 100nA. It includes programmable watchdog timers, RTC alarms, power-on reset, and battery monitors.

Real Time Clock Feature Summary

• Y2K-Compliant RTC with Century Register and Automatic Leap-Year Compensation
• 256 Bytes Battery-Backed NVSRAM with Parallel Interface
• Programmable Watchdog Timer and Day-of-Week/Date Alarm
• Precision Power-On Reset and Power-Control Circuitry for System Wakeup

Real Time Clock Applications

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

Real Time Clock Procurement Notes

Verify the ordering suffix T&R indicates Tape and Reel packaging. Confirm the N suffix denotes the industrial temperature grade (-40°C to +85°C). Ensure the W suffix corresponds to the 3.3V operation variant. Check for lead-free/RoHS compliance status indicated by the '+' symbol. Validate availability through authorized channels as distribution may be restricted.

Real Time Clock Selection Notes

Select this model for applications requiring 3.3V logic levels and industrial temperature stability. The parallel interface requires sufficient address and data lines. Ensure external crystal selection matches the 6pF or 12.5pF load capacitance settings via the CS bit. Verify that the system can accommodate the required pull-up resistors for open-drain outputs like IRQ, PWR, and RST.

Real Time Clock Part Context

This component belongs to the DS1501/DS1511 family of Y2K-compliant watchdog real-time clocks. The DS1501 series provides standalone RTC functionality with integrated NVSRAM, distinguishing it from the DS1511 which is an encapsulated module with an embedded battery and crystal. The DS1501WEN/T&R specifically represents the surface-mount, industrial-grade, 3.3V version.

Real Time Clock Replacement Considerations

Direct pin-compatible replacements within the same family include DS1501WE+ (commercial temp) or DS1501WE+T&R. For 5V operation, consider the DS1501YE+ variants. Cross-family replacement requires verifying interface compatibility and voltage levels.