BQ3285LDSSG4

Overview

The BQ3285LDSSG4 is a Real-Time Clock (RTC) IC manufactured by Texas Instruments, belonging to the BQ3285 family. It integrates a clock/calendar function with 242 bytes of Non-Volatile Static RAM (NVSRAM). The device operates on a parallel interface and supports supply voltages between 2.7V and 5.5V for main power, and 2.4V to 4V for battery backup. Key features include alarm capabilities, daylight saving time adjustment, leap year compensation, and a square wave output. It is housed in a 24-SSOP package with a width of 3.90mm and functions within an operating temperature range of 0°C to 70°C.

Feature Summary

• Integrated 242-byte NVSRAM for data retention during power loss
• Parallel interface supporting standard RTC protocols
• Hardware support for alarms, daylight saving time, and leap years
• Low current consumption of 100µA maximum at 3V

Applications

• Industrial control systems requiring precise timekeeping
• Data logging equipment needing non-volatile storage
• Consumer electronics with calendar functionality
• Embedded systems with parallel bus architectures

Procurement Notes

Verify component authenticity through authorized distributors or certified secondary market suppliers. Confirm RoHS3 compliance status as indicated by the G4 suffix. Check for End-of-Life (EOL) notices, as the base BQ3285LF series was subject to discontinuation announcements. Ensure compatibility with existing PCB footprints for the 24-SSOP package before procurement.

Selection Notes

Select this component when a parallel interface is required rather than I2C or SPI alternatives. Ensure the design accommodates the 24-SSOP package dimensions. Verify that the system voltage ranges align with the 2.7V to 5.5V specification. Consider the 100µA current draw for battery life calculations if used in low-power applications.

Part Context

This part is a variant within the BQ3285 family, distinguished by the 'L' indicating lead-free/RoHS compliance and 'G4' denoting specific manufacturing or packaging updates. It shares core functionalities with other BQ3285 models but may differ in environmental compliance or specific package markings. The base model BQ3285 is widely recognized for its combination of RTC and NVSRAM capabilities.

Replacement Considerations

Direct pin-to-pin replacements may be limited due to the specific parallel interface and NVSRAM integration. Evaluate other BQ3285 variants for functional equivalence. For modern designs, consider newer RTCs with serial interfaces, though these will require schematic and layout modifications.