Renesas 1337AGCSRGI

Overview

1337AGCSRGI from IDT (now part of Renesas) is a low-power I²C real-time clock IC with integrated crystal, providing full calendar/timekeeping (seconds to years), two programmable alarms, and a configurable square-wave output. It operates from 1.8 V to 5.5 V across –40°C to +85°C and supports leap-year compensation through 2100 - used in telecom routers, medical glucometers, and utility meters for accurate time stamping and alarm-triggered events.

For engineers reviewing the 1337AGCSRGI datasheet, 1337AGCSRGI pinout, 1337AGCSRGI application, or 1337AGCSRGI equivalent, key selection criteria include its factory-integrated 32.768 kHz crystal (±10 ppm at 3.3 V/25°C), dual interrupt outputs (INTA and SQW/INTB), BCD register format, and guaranteed timekeeping down to 1.3 V during backup operation.

Technical Context

The 1337AGCSRGI implements a fully autonomous RTC core with binary-coded decimal (BCD) time/calendar registers, oscillator stop flag (OSF) monitoring, and dual alarm logic that supports date-, day-of-week-, or periodic (e.g., hourly) match modes. Its I²C slave interface complies with standard (100 kHz) and fast (400 kHz) modes, using open-drain SDA/SCL with external pull-ups.

It integrates a 32.768 kHz quartz crystal inside the 16-pin SOIC package - eliminating external crystal layout sensitivity - and features programmable SQW/INTB output frequencies (1 Hz, 4.096 kHz, 8.192 kHz, or 32.768 kHz) controlled via RS1/RS2 bits in the control register (0Eh). The device maintains timekeeping at V_CC as low as 1.3 V, enabling seamless battery-backup operation without external supervision.

Key Specifications

Pinout & Package

1337AGCSRGI is packaged in a 16-pin SOIC with integrated 32.768 kHz crystal. All NC pins (pins 4–13) must be connected to ground per datasheet requirement. The package includes internal load capacitance optimized for 7 pF crystal CL.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar real-time clock applications.

Compared with DS3231SN#T&R and PCF8563T/2,118, the 1337AGCSRGI uniquely balances factory-calibrated accuracy, zero-component integration, and sub-µA timekeeping - making it optimal for industrial and medical designs requiring long-life reliability without calibration overhead.

Availability

1337AGCSRGI is available at Aetrix Electronics and suitable for telecom infrastructure, medical diagnostics, utility metering, and office equipment requiring stable component supply, long-lifecycle support, and guaranteed timekeeping performance across industrial temperature ranges.

Supply support for 1337AGCSRGI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

IDT (Integrated Device Technology), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, and RF solutions for high-reliability systems.

The 1337AGCSRGI belongs to IDT's precision RTC product line, designed specifically for applications demanding integrated crystal accuracy, ultra-low power, and robust I²C interoperability in space-constrained industrial and medical platforms.

FAQ

What is the crystal configuration of the 1337AGCSRGI?

The 1337AGCSRGI integrates a factory-tuned 32.768 kHz quartz crystal inside its 16-pin SOIC package, with specified load capacitance of 7 pF and typical frequency error of ±10 ppm at 3.3 V and 25°C. No external crystal or load capacitors are required - X1 and X2 pins are internally connected and must not be externally loaded. This integration eliminates crystal layout sensitivity and reduces total solution size.

Does the 1337AGCSRGI support both 12-hour and 24-hour time formats?

Yes, the 1337AGCSRGI supports both formats. Bit 6 of the hours register (02h) selects mode: logic high enables 12-hour format with AM/PM indicated by bit 5, while logic low enables 24-hour format where bit 5 becomes the tens digit for hours 20–23. All time and alarm registers must be reinitialized when switching modes, and the century bit (bit 7 of month register 05h) toggles automatically at year rollover from 99 to 00.

How does the oscillator stop flag (OSF) function in the 1337AGCSRGI?

The OSF bit (bit 7 of Status Register 0Fh) is set to logic 1 whenever the oscillator stops - including at initial power-up, under-voltage conditions (<1.3 V), EOSC bit disable, or crystal disturbance. It remains asserted until explicitly cleared to logic 0 by firmware. This flag enables reliable validation of time validity before acting on RTC data, preventing erroneous timestamps after brownout or crystal failure.

Can the 1337AGCSRGI operate from a single 3.3 V supply?

Yes, the 1337AGCSRGI operates fully across 1.8 V to 5.5 V, with typical V_CC = 3.3 V. At 3.3 V, it delivers 725–900 nA oscillator current and ±10 ppm accuracy with integrated crystal. I²C communication remains functional across this range, and timekeeping continues down to 1.3 V - allowing seamless transition to coin-cell backup without level-shifting or voltage supervision circuitry.

What are the interrupt capabilities of the 1337AGCSRGI?

The 1337AGCSRGI provides two dedicated interrupt outputs: INTA (pin 15) for Alarm 1 and SQW/INTB (pin 16) for Alarm 2 or programmable square-wave generation. The INTCN bit (bit 2 of Control Register 0Eh) configures routing: when INTCN = 1, alarms drive separate pins; when INTCN = 0, SQW/INTB outputs square wave and INTA handles both alarms. Both pins are open-drain and require external pull-ups (10 kΩ typical).