DS1305EN/T&R

Real Time Clock Overview

The DS1305EN/T&R is a serial alarm real-time clock in a 20-pin TSSOP package, rated for the -40°C to +85°C industrial temperature range. It provides binary coded decimal (BCD) timekeeping for seconds through year with leap-year compensation valid to 2100. The device includes 96 bytes of battery-backed NV RAM and two programmable time-of-day alarms. It operates on a single supply voltage between 2.0V and 5.5V. Serial communication is supported via SPI Modes 1 and 3 or a standard 3-wire interface, selectable via the SERMODE pin.

Real Time Clock Feature Summary

• Dual power supply architecture supporting primary (VCC1), backup (VCC2), and battery (VBAT) inputs with automatic switching.
• Programmable trickle charger circuit for maintaining rechargeable backup sources such as super capacitors.
• Two independent time-of-day alarms with interrupt outputs (INT0, INT1) and configurable mask bits.
• Interface logic power supply (VCCIF) allows compatibility with 3V logic systems.

Real Time Clock Applications

• Industrial control systems requiring reliable timekeeping in wide temperature environments.
• Data logging equipment utilizing the 96-byte NV RAM for non-volatile storage.
• Embedded devices needing scheduled interrupts via dual programmable alarms.

Real Time Clock Procurement Notes

Verify that the ordering suffix 'T&R' corresponds to the tape and reel packaging format specified in the manufacturer's documentation. Confirm the 'EN' designation indicates the industrial temperature grade (-40°C to +85°C). Ensure the component meets RoHS compliance requirements if applicable to the assembly process.

Real Time Clock Selection Notes

Select this model when an industrial temperature range is required compared to the commercial variant. Choose the TSSOP package for surface-mount applications requiring space efficiency. Ensure the system design accommodates the dual power supply pins for primary and backup configurations.

Real Time Clock Part Context

This component belongs to the DS1305 family of serial alarm real-time clocks. The 'EN' suffix denotes the industrial temperature extension, while '+T&R' specifies the lead-free/RoHS-compliant package in tape and reel form. It shares functional similarities with other Maxim Integrated RTCs but offers specific dual-supply flexibility.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material.