BQ4847MT

Overview

The BQ4847MT is a discontinued Real-Time Clock (RTC) module with an integrated CPU supervisor, manufactured by Texas Instruments. It features a built-in 130mAh battery and crystal within a 28-pin T-type DIP package. The device provides time-of-day counting and a 100-year calendar in BCD format with ±1 minute per month accuracy at room temperature. It includes a microprocessor reset valid to VSS, an independent watchdog timer, power-fail interrupt warning, and programmable clock alarm and periodic interrupts. The module supports nonvolatile control for external SRAM via conditional chip enable output.

Feature Summary

• Integrated 130mAh backup battery and quartz crystal in a 28-pin DIP module
• Real-time clock with 100-year calendar and ±1 minute/month accuracy
• CPU supervisor with microprocessor reset, watchdog timer, and power-fail interrupt
• Programmable clock alarm and periodic interrupts active in battery-backup mode

Applications

• Fax machines
• Copiers
• Industrial control systems
• Point-of-sale terminals
• Data loggers

Procurement Notes

The BQ4847MT is listed as OBSOLETE in the Texas Instruments packaging information addendum. Production has been discontinued. Verification of current availability requires direct contact with the manufacturer or authorized distributors, as standard ordering channels may no longer support this part number.

Selection Notes

This component is not recommended for new designs due to its obsolete status. Designers should evaluate alternative RTC modules with similar interface requirements and integrated supervision features that are currently in production. Considerations include package compatibility, interrupt capabilities, and battery life specifications.

Part Context

The bq4847 is functionally equivalent to the bq4845, except the battery and crystal pins are internal rather than accessible. Valid ordering types include bq4847MT (5% voltage tolerance) and bq4847YMT (10% voltage tolerance). The MT suffix denotes a 28-pin T-type plastic dual-in-line package.

Replacement Considerations

No public confirmed substitute part numbers are provided in the source material. As the device is obsolete, designers must identify modern equivalents based on functional requirements such as RTC functionality, CPU supervision, and package type.