ISL12030IBZ-T

Real Time Clock Overview

The ISL12030IBZ-T is a low-power real-time clock (RTC) manufactured by Renesas Electronics Corporation, packaged in an 8-lead SOIC. It utilizes a 50/60 Hz AC input for timing synchronization rather than a traditional crystal oscillator. The device features an I2C interface with a maximum data transfer rate of 400 kHz and includes 128 bytes of user-accessible SRAM. Operating specifications define a supply voltage range of 2.7 V to 5.5 V and an industrial temperature range from -40°C to +85°C. The RTC tracks time including tenths of a second and provides automatic leap year correction through the year 2100.

Real Time Clock Feature Summary

• Primary clock source derived from 50/60 Hz AC input signal
• Integrated 128-byte battery-backed user SRAM
• Dual alarms with single event or periodic interrupt modes
• Automatic Daylight Saving Time (DST) forward and backward correction

Real Time Clock Applications

• Utility meters
• Control applications
• Vending machines
• White goods
• Consumer electronics

Real Time Clock Procurement Notes

Verify that the specific ordering suffix '-T' corresponds to tape and reel packaging as defined in the manufacturer's technical brief TB347. Confirm that the host system can provide a clean 50Hz or 60Hz sine wave signal on the AC pin, as this component lacks an internal crystal oscillator. Ensure the application environment remains within the specified -40°C to +85°C operating temperature range.

Real Time Clock Selection Notes

Select this component only if the target application has access to a stable 50/60 Hz AC power line for clock synchronization. The device requires a minimum AC amplitude greater than 0.2 times VDD. Designers must account for the 128-byte SRAM volatility below 1.8 V and implement appropriate power failure detection using the RTCF bit if data retention during brownouts is critical.

Real Time Clock Part Context

The ISL12030 belongs to the Intersil/Renesas family of AC-powered real-time clocks. The 'IBZ' designation indicates a Pb-free plastic package compliant with RoHS standards, while the '-T' suffix specifies the reel packaging format for automated surface-mount assembly. This part replaces older crystal-based RTCs in environments where mains frequency accuracy is preferred.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Replacement requires verifying compatibility with the AC input buffer requirements and I2C register map of the existing design.

Real Time Clock FAQ

How does the ISL12030 handle timekeeping without a crystal?

The device uses the frequency of the external AC power line (50Hz or 60Hz) connected to the AC pin as its primary clock source for timing synchronization.

What is the function of the WRTC bit?

The Write RTC Enable (WRTC) bit must be set to '1' to allow writes to the Real-Time Clock registers. Upon completion of a valid write cycle, the RTC begins counting.

How is the alarm interrupt configured?

The Interrupt Mode (IM) bit determines the behavior. When set to '1', the IRQ pin outputs a 250ms pulse for each alarm match. When '0', the IRQ pin remains low until the alarm status bits are manually cleared.