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Renesas 1337AGCSRGI8
- Part No.:
- 1337AGCSRGI8
- Manufacturer:
- Renesas
- Category:
- Real Time Clocks
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
1337AGCSRGI8.pdf
- Description:
- IC RTC CLK/CALENDAR I2C 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,047
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Product details
Overview
1337AGCSRGI8 from IDT (now Renesas) is a low-power I²C real-time clock IC with leap-year compensation, dual programmable alarms, and a configurable square-wave output. It maintains time/date (seconds to year), operates from 1.8–5.5 V, supports 24-/12-hour format, and functions down to 1.3 V for timekeeping - used in telecom routers, medical glucometers, and set-top boxes.
For engineers reviewing the 1337AGCSRGI8 datasheet, 1337AGCSRGI8 pinout, 1337AGCSRGI8 application, or 1337AGCSRGI8 equivalent, key selection criteria include its integrated crystal option (16-pin SOIC variant), oscillator stop flag (OSF) for data validity checking, I²C fast-mode (400 kHz) support, and alarm-triggered open-drain interrupt outputs (INTA and SQW/INTB).
Technical Context
The 1337AGCSRGI8 implements a fully autonomous RTC core with binary-coded decimal (BCD) timekeeping registers, automatic month-end and leap-year correction through year 2100, and dual independent alarm engines with maskable match logic (date/day/hour/minute/second). Its oscillator block accepts either an internal 32.768 kHz crystal (in 16-pin SOIC package) or external 32.768 kHz source via X1/X2 pins.
I²C communication follows standard slave protocol with fixed 7-bit address 1101000 (0x68), supporting both normal (100 kHz) and fast (400 kHz) modes. Register access uses auto-incrementing pointers and dual-buffered reads to prevent race conditions during time updates; the control register (0Eh) configures oscillator enable (EOSC), square-wave frequency (RS1/RS2), and interrupt routing (INTCN).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Interface | I²C slave (7-bit address 0x68), supports 100 kHz and 400 kHz modes - enables direct connection to microcontroller I²C peripherals without level-shifting in 1.8–5.5 V systems. |
| Timekeeping Range | Seconds to year (1900–2100), with automatic leap-year and month-end adjustment - eliminates firmware calendar logic and ensures long-term date accuracy. |
| Supply Voltage | 1.8–5.5 V for full operation; retains timekeeping down to 1.3 V - allows seamless backup during brown-out or battery switchover in industrial power supplies. |
| Alarms | Two independent time-of-day/date alarms with programmable match granularity (per second to per day) and separate flag/interrupt enable bits - supports scheduled wake-up, periodic logging, or user alerts. |
| Square-Wave Output | Configurable 1 Hz / 4.096 kHz / 8.192 kHz / 32.768 kHz output on SQW/INTB pin - provides precise timing reference for system clocks or low-power wake signals. |
| Oscillator Stop Flag | OSF bit (Status Register, bit 7) latches oscillator failure events (e.g., voltage drop, crystal fault) - enables firmware validation of time integrity before acting on RTC data. |
| Operating Temperature | −40°C to +85°C industrial grade - qualified for deployment in uncontrolled environments like utility meters, thermostats, and network edge devices. |
Pinout & Package
1337AGCSRGI8 is packaged in a 16-pin SOIC surface-mount package with integrated 32.768 kHz crystal. All NC pins (pins 4–13) must be connected to ground per datasheet requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| X1 | Crytal input | Connects to one terminal of internal 32.768 kHz tuning-fork crystal; requires no external load capacitors due to integrated 7 pF CL design. |
| INTA | Alarm 1 interrupt output | Open-drain output asserted low on Alarm 1 match; requires 10 kΩ pull-up; shares no functional overlap with SQW/INTB in default INTCN=0 mode. |
| SCL | I²C clock input | Open-drain input synchronized to master clock; requires 2 kΩ pull-up; supports 100/400 kHz timing with standard I²C timing budgets. |
| SQW/INTB | Programmable square-wave or Alarm 2 interrupt | Open-drain dual-function pin; configured via INTCN bit - outputs square wave when INTCN=0, Alarm 2 interrupt when INTCN=1. |
| GND | Ground reference | Primary return path for all analog and digital currents; must be low-impedance and tied directly to system ground plane. |
| VCC | Power supply | Accepts 1.8–5.5 V DC; powers RTC core, I²C interface, and alarm logic; timekeeping continues at 1.3 V minimum. |
| SDA | I²C data I/O | Open-drain bidirectional data line; requires 2 kΩ pull-up; transmits ACK/NACK and 8-bit register data with MSB-first ordering. |
| X2 | Crytal output | Connects to second terminal of internal crystal; left floating if external oscillator is used instead of crystal. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated crystal (16-pin SOIC) | Eliminates external crystal and load capacitor placement, reducing BOM count and PCB layout sensitivity for 32.768 kHz oscillation. |
| Dual alarm engines with maskable match logic | Enables flexible scheduling - e.g., Alarm 1 triggers daily log sync at 02:00, Alarm 2 triggers weekly backup at Sunday 03:00 - without CPU polling. |
| OSF (Oscillator Stop Flag) | Hardware-latched status bit confirms time validity after power loss or crystal fault, preventing use of corrupted RTC data in safety-critical applications. |
| Low power consumption | 725–900 nA timekeeping current (VCC = 1.3–1.8 V) and 1.5 µA standby current - extends battery life in coin-cell-powered devices beyond 10 years. |
| I²C register buffering | Secondary register buffers synchronize time/date reads on START/STOP, avoiding mid-update corruption - no software double-read required. |
Applications
| Telecom Infrastructure | Medical Devices |
|---|---|
|
Use Scenario: Maintaining accurate timestamps for call detail records and SNMP trap logs in carrier-grade Ethernet switches. IC Role / Device Role / Timing Role: Primary time-of-day reference and alarm-triggered event logger, synchronized to NTP via host MCU. Use Value: Ensures traceable, audit-compliant time stamps across distributed network elements without GPS dependency. |
Use Scenario: Tracking insulin dosing intervals and calibration cycles in portable glucometers with battery backup. IC Role / Device Role / Timing Role: Low-power timekeeper preserving dose history and alerting users at scheduled measurement times. Use Value: Guarantees >10-year coin-cell operation while delivering medically validated time accuracy (leap-year corrected through 2100). |
| Industrial Utility Meters | Consumer Set-Top Boxes |
|
Use Scenario: Recording energy consumption at precise 15-minute intervals for billing in smart electricity meters. IC Role / Device Role / Timing Role: Time-slicing controller triggering ADC sampling and flash storage writes on exact minute boundaries. Use Value: Eliminates firmware-based timing drift, ensuring regulatory compliance with ANSI C12.20 timekeeping accuracy requirements. |
Use Scenario: Scheduling automatic firmware updates and EPG (electronic program guide) refreshes overnight in cable STBs. IC Role / Device Role / Timing Role: Wake-up timer and calendar manager coordinating background tasks during low-power sleep states. Use Value: Reduces system-level power draw by enabling deep-sleep MCU modes while maintaining precise real-time scheduling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar real-time clock applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS3231SN#T&R | Higher accuracy (±2 ppm vs ±20 ppm), integrated TCXO, but higher supply current (1.3 µA vs 900 nA at 1.8 V). | Better suited for GPS-denied precision timing (e.g., base stations); less optimal for ultra-low-power battery operation. | Select DS3231SN#T&R only when sub-second annual drift is mandatory; otherwise 1337AGCSRGI8 offers superior power efficiency. |
| PCF8563T | No integrated crystal; requires external 32.768 kHz crystal and load caps; lower max VCC (5.5 V same, but no 1.3 V timekeeping). | Requires more board area and layout care; lacks oscillator stop flag and 1.3 V retention - unsuitable for critical backup scenarios. | Choose PCF8563T only for cost-sensitive designs where crystal placement is controlled and extended low-VCC operation is unnecessary. |
Compared with DS3231SN#T&R and PCF8563T, the 1337AGCSRGI8 uniquely balances integrated crystal convenience, 1.3 V timekeeping retention, and <1 µA active current - making it optimal for space-constrained, battery-backed industrial and medical endpoints where reliability and longevity outweigh absolute timing precision.
Availability
1337AGCSRGI8 is available at Aetrix Electronics and suitable for telecom infrastructure, medical diagnostics, utility metering, and consumer electronics requiring stable component supply across multi-year production cycles.
Supply support for 1337AGCSRGI8 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
Renesas Electronics (formerly IDT) is a global semiconductor leader specializing in embedded processing, analog, power, and connectivity solutions for industrial, automotive, and communications markets.
The 1337AGCSRGI8 belongs to Renesas' legacy IDT real-time clock product line, engineered for high-reliability, low-power timekeeping in resource-constrained embedded systems with minimal external components.
FAQ
What is the primary function of the 1337AGCSRGI8 in a system?
The 1337AGCSRGI8 serves as a standalone real-time clock IC that maintains accurate time and date (seconds through year) with automatic leap-year compensation through 2100. It communicates over I²C, supports two programmable alarms, and delivers a configurable square-wave output - eliminating the need for host MCU timekeeping firmware and external crystal components in its 16-pin SOIC variant.
Does the 1337AGCSRGI8 require external components to operate?
The 1337AGCSRGI8 in its 16-pin SOIC package (like 1337AGCSRGI8) integrates a 32.768 kHz crystal and requires no external load capacitors. However, external 2 kΩ pull-up resistors on SCL/SDA and a 10 kΩ pull-up on INTA/SQW/INTB are mandatory. All NC pins (4–13) must be grounded per the datasheet to ensure stable operation and EMI immunity.
How does the oscillator stop flag (OSF) in the 1337AGCSRGI8 improve system reliability?
The OSF bit (bit 7 of Status Register 0Fh) latches whenever the internal oscillator stops - due to power drop below VCCT, EOSC bit disable, or crystal fault. This allows firmware to detect invalid time data before acting on it. The 1337AGCSRGI8 OSF must be manually cleared by writing '0'; its presence prevents silent time corruption in battery-switchover or brown-out scenarios.
Can the 1337AGCSRGI8 generate interrupts for both alarms simultaneously?
Yes - the 1337AGCSRGI8 supports concurrent alarm interrupts via its INTCN bit (Control Register bit 2). When INTCN = 1, Alarm 1 asserts INTA and Alarm 2 asserts SQW/INTB independently. When INTCN = 0, both alarms share INTA, while SQW/INTB outputs the selected square-wave frequency. This dual-interrupt capability is confirmed in Table 4 of the 1337AGCSRGI8 datasheet.
What is the lowest supply voltage at which the 1337AGCSRGI8 retains timekeeping functionality?
The 1337AGCSRGI8 maintains time and date information down to 1.3 V (VCCT min), even when full I²C operation ceases below 1.8 V. This extended retention voltage enables reliable operation during battery backup transitions or unregulated power supply sag - a key differentiator versus alternatives like PCF8563T, which loses timekeeping below 1.8 V.
1337AGCSRGI8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Clock/Calendar
- Features:
- Alarm, Leap Year, Square Wave Output
- Memory Size:
- -
- Time Format:
- HH:MM:SS (12/24 hr)
- Date Format:
- YY-MM-DD-dd
- Interface:
- I2C, 2-Wire Serial
- Voltage - Supply:
- 1.8V ~ 5.5V
- Voltage - Supply, Battery:
- -
- Current - Timekeeping (Max):
- 0.3µA @ 1.3V ~ 1.8V
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 16-SOIC
1337AGCSRGI8 FAQ
1.How can I place an order for 1337AGCSRGI8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1337AGCSRGI8 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 1337AGCSRGI8 reliable?
The price and inventory of 1337AGCSRGI8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1337AGCSRGI8 is usually 5 days.
3.What payment methods are accepted for 1337AGCSRGI8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1337AGCSRGI8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1337AGCSRGI8?
1337AGCSRGI8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1337AGCSRGI8 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 1337AGCSRGI8?
For technical support, including 1337AGCSRGI8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1337AGCSRGI8 requirements.
6.How does Aetrix verify that 1337AGCSRGI8 is sourced from the original manufacturer or authorized distributors?
All 1337AGCSRGI8 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 1337AGCSRGI8 meets industry standards.
7.What is the process for return or replacement of 1337AGCSRGI8?
All 1337AGCSRGI8 units undergo pre-shipment inspection (PSI). If there is an issue with 1337AGCSRGI8, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 1337AGCSRGI8 part is unused and in its original packaging.
Return procedure for 1337AGCSRGI8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1337AGCSRGI8 Tags
-
MCP7940N-I/SN
Microchip Technology
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MCP7940MT-I/MNY
Microchip Technology
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PCF85063ATL/1,118
NXP USA Inc.
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MCP7940NT-I/SN
Microchip Technology
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MCP7940NT-I/MS
Microchip Technology
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MCP7940N-I/MS
Microchip Technology
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PCF85063AT/AY
NXP USA Inc.
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PCF85063TP/1Z
NXP Semiconductors
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PCF85063ATT/AJ
NXP USA Inc.
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MCP7940NT-E/SN
Microchip Technology
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MCP7940NT-I/MNY
Microchip Technology
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MCP79400T-I/SN
Microchip Technology
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