S-35390AH-J8T2U

Real Time Clock Overview

The S-35390AH-J8T2U is an automotive-grade real-time clock IC designed for operation up to 105°C. It features a 2-wire I²C interface and operates within a voltage range of 1.3 V to 5.5 V. Timekeeping current consumption is typically 0.25 µA at 3.0 V. The device includes an internal 32.768 kHz oscillator, auto-calendar functionality until 2099 with leap year calculation, and built-in alarm interrupters. It provides free user registers for backup memory and supports clock correction functions.

Real Time Clock Feature Summary

• Automotive qualification (AEC-Q100 Grade 2) with -40°C to +105°C operating temperature
• Low timekeeping current consumption of 0.25 µA typ. at 3.0 V
• Built-in 32.768 kHz crystal oscillation circuit with external Cg
• Auto-calendar function supporting years up to 2099 with automatic leap year detection

Real Time Clock Applications

• Vehicle equipment and in-vehicle systems
• Backup battery powered real-time clocks
• Systems requiring low power consumption during main supply failure

Real Time Clock Procurement Notes

Verify AEC-Q100 reliability specifications directly with the manufacturer's sales office as detailed documentation is not included in standard datasheets. Confirm package availability for the 8-Pin SOP (JEDEC) variant associated with the J8T2 suffix. Ensure compliance with halogen-free and lead-free (Sn 100%) requirements specified for the U environmental code.

Real Time Clock Selection Notes

Select this model for applications requiring extended high-temperature operation up to 105°C. The J8T2 suffix indicates the 8-Pin SOP (JEDEC) package with tape packing. Ensure the system design accommodates the required external capacitance (Cg) for the quartz crystal, typically up to 9.1 pF, to meet oscillation characteristics.

Real Time Clock Part Context

This component belongs to the S-35390A H Series, which is specifically engineered for automotive environments. The 'H' designation denotes the high-temperature capability (-40°C to +105°C). The series integrates CMOS technology to achieve low current consumption while maintaining precise timekeeping through an internal constant voltage circuit and clock correction register.

Real Time Clock Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation. Contact ABLIC Inc. sales for alternative recommendations if specific pinouts or electrical parameters differ from existing designs.

Real Time Clock FAQ

How is the power-on state detected?

The POC flag (Bit 0 of Status Register 1) is set to '1' when power is applied. This flag is read-only and automatically clears to '0' upon reading.

What is the function of the BLD flag?

The BLD flag (Bit 1 of Status Register 1) is set to '1' when the power supply voltage drops to the detection voltage (VDET) or below. It remains '1' even if voltage recovers, indicating a low-power event.

Can the clock frequency be corrected?

Yes, the device includes a clock correction register that allows users to correct advance or delay of the clock data speed caused by crystal oscillation circuit frequency deviations.