DS1673E-3

Real Time Clock Overview

The DS1673E-3 is a portable system controller integrating a real-time clock (RTC), nonvolatile RAM controller, microprocessor monitor, and a 3-channel, 8-bit analog-to-digital converter (ADC). Operating at +3.0V with a supply range of 2.7V to 3.3V, it features a 3-wire serial interface and TSSOP-20 packaging. The RTC provides timekeeping with leap year compensation up to 2100 and supports system wake-up via alarms. It manages external SRAM backup through automatic write protection and power switchover from VCC to VBAT. The device includes watchdog timer functionality and pushbutton reset control for system stability.

Real Time Clock Feature Summary

• Integrates RTC with alarm interrupt, NV SRAM controller, microprocessor monitor, and 3-channel 8-bit ADC
• Supports +3.0V operation with battery backup switchover and automatic SRAM write protection
• Features watchdog timer with selectable timeouts (250ms, 500ms, 1000ms) and pushbutton reset debouncing
• Communicates via simple 3-wire serial interface (CS, SCLK, I/O)

Real Time Clock Applications

• Low-power portable consumer electronics requiring integrated timekeeping and memory management
• Microprocessor-based systems needing reliable power-fail detection and reset generation
• Battery-operated devices utilizing external SRAM for data retention during power loss

Real Time Clock Procurement Notes

Verify the specific ordering suffix (+ or /T&R) against the required package style (TSSOP) and lead-free status. Confirm that the +3.0V voltage variant matches the system power supply requirements. Ensure the operating temperature range of 0°C to +70°C is suitable for the intended environment. Check for availability constraints as distribution may vary by region.

Real Time Clock Selection Notes

Select the DS1673E-3 when a +3.0V supply is available and integration of RTC, SRAM control, and ADC is required. Choose this component over the DS1673E-5 if lower power consumption at 3.0V is prioritized. Ensure the application utilizes a 32.768kHz crystal with 6pF load capacitance for accurate timekeeping. Verify that the external SRAM interface requirements align with the CEOL/CEOH chip-enable signals.

Real Time Clock Part Context

The DS1673E-3 belongs to the DS1673 family of portable system controllers manufactured by Analog Devices Inc./Maxim Integrated. It shares functional architecture with the DS1673E-5 but differs in nominal operating voltage (+3.0V vs +5.0V). The 'E' designation indicates an industrial temperature range (0°C to +70°C), while the '+' suffix denotes RoHS compliance. It serves as a consolidated solution for embedded systems previously requiring separate RTC, supervisor, and memory controller ICs.

Real Time Clock Replacement Considerations

The DS1673E-5+ is a direct pin-compatible alternative offering +5.0V operation instead of +3.0V. Verify that the system power supply voltage matches the replacement part's requirement before substitution.