BQ4802YDSH

Overview

The BQ4802YDSH is a parallel real-time clock (RTC) with CPU supervisor and external SRAM nonvolatile memory backup, manufactured by Texas Instruments. It operates at 5 V within an ambient temperature range of 0°C to +70°C. The device integrates a time-of-day clock, century-based calendar, and watchdog timer in a 28-pin SNAPHAT package. Key electrical parameters include a typical battery operation supply current of 0.5 µA at 3 V, a read cycle time of 200 ns, and address access times up to 100 ns. It provides direct connections for a 32.768-kHz quartz crystal and a 3-V backup battery.

Feature Summary

• Real-Time Clock counts seconds through centuries in BCD format
• On-chip battery-backup switchover circuit with nonvolatile control for external SRAM
• Microprocessor reset with push-button override and independent watchdog timer
• Programmable clock alarm interrupt active in battery-backup mode

Applications

• Telecommunications base stations
• Servers
• Handheld data collection equipment
• Medical equipment
• Test equipment

Procurement Notes

Verify the specific ordering suffix against the manufacturer's documentation to confirm package type and voltage rating. The DSH package requires the bq48SH-28x6 component to complete the two-piece module. Confirm RoHS compliance status and check for any product discontinuation notices or end-of-life notifications prior to procurement.

Selection Notes

Select the BQ4802YDSH for applications requiring a 5-V parallel RTC interface with integrated CPU supervision. Ensure the design accommodates the 28-pin SNAPHAT form factor and includes the necessary bq48SH-28x6 socket component. Verify that the system supports the required 32.768-kHz crystal specifications and 3-V lithium cell backup requirements.

Part Context

The BQ4802YDSH belongs to the bq4802Y/bq4802LY family of parallel real-time clocks. It shares functional characteristics with other variants like the bq4802YDW and bq4802YPW but utilizes a distinct SNAPHAT package configuration. This module approach integrates the primary IC with the crystal and battery holder components into a single assembly solution.

Replacement Considerations

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