Equivalent & Substitute Parts for 1337DCGI8

Part Overview

The 1337DCGI8 is a Real Time Clock (RTC) IC with Clock/Calendar functionality, manufactured by Renesas Electronics Corporation. This device features I2C (2-Wire Serial) interface, alarm capability, leap year support, and square wave output in an 8-SOIC surface mount package. The part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across timing accuracy, interface protocol, and electrical operating parameters.

Key Parameters

Parameter	1337DCGI8 Specification
Manufacturer	Renesas Electronics Corporation
Product Status	Obsolete
Package / Case	8-SOIC (0.154", 3.90mm Width)
Type	Clock/Calendar
Interface	I2C, 2-Wire Serial
Voltage - Supply	1.8V ~ 5.5V
Current - Timekeeping (Max)	0.6µA @ 1.3V ~ 1.8V
Operating Temperature	-40°C ~ 85°C
Time Format	HH:MM:SS (12/24 hr)
Date Format	YY-MM-DD-dd
Features	Alarm, Leap Year, Square Wave Output
Mounting Type	Surface Mount

Substitute Part Grouping Explanation

Substitution compatibility for the 1337DCGI8 is determined by the following critical parameters:

Primary Compatibility Criteria:

Interface Protocol: I2C, 2-Wire Serial (mandatory)
Time Format: HH:MM:SS with 12/24 hour support
Date Format: YY-MM-DD-dd
Operating Temperature Range: -40°C ~ 85°C minimum
Supply Voltage Range: Must encompass or overlap 1.8V ~ 5.5V
Features: Alarm and Leap Year support (core functionality)

Package Considerations:

8-SOIC (0.154", 3.90mm Width) represents the primary form factor
Alternative packages (8-TSSOP, 8-MSOP, 10-SMD Module, 16-VFQFN, 16-SOIC) are acceptable for designs with layout flexibility

Substitutes are grouped into two categories:

Direct Pin-Compatible Substitutes (8-SOIC Package): ISL12057IBZ, ISL12057IBZ-T, DS1337S+, DS1337S+T&R
Functional Equivalents (Alternative Packages): AB-RTCMC-32.768KHZ-B5GA-S3-T, AB1805-T3, DS1307ZN+, DS1308U-3+, DS1337U+T&R, DS1340C-33#T&R

Parameter Comparison

Parameter	1337DCGI8	ISL12057IBZ / ISL12057IBZ-T	DS1337S+ / DS1337S+T&R	AB-RTCMC-32.768KHZ-B5GA-S3-T	AB1805-T3	DS1307ZN+	DS1308U-3+	DS1337U+T&R	DS1340C-33#T&R
Manufacturer	Renesas	Renesas	Analog Devices/Maxim	Abracon	Abracon	Analog Devices/Maxim	Analog Devices/Maxim	Analog Devices/Maxim	Analog Devices/Maxim
Product Status	Obsolete	Active	Active	Active	Active	Active	Active	Active	Active
Package / Case	8-SOIC	8-SOIC	8-SOIC	10-SMD Module	16-VFQFN	8-SOIC	8-TSSOP/MSOP	8-TSSOP/MSOP	16-SOIC
Interface	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire	I2C, 2-Wire
Voltage - Supply	1.8V ~ 5.5V	1.8V ~ 3.6V	1.8V ~ 5.5V	1.2V ~ 5.5V	1.7V ~ 3.6V	4.5V ~ 5.5V	2.7V ~ 5.5V	1.8V ~ 5.5V	2.97V ~ 5.5V
Current - Timekeeping (Max)	0.6µA @ 1.3V ~ 1.8V	0.65µA @ 1.8V	0.6µA @ 1.3V ~ 1.8V	0.45µA ~ 0.55µA @ 2V ~ 5V	0.17µA ~ 0.22µA @ 1.8V ~ 3V	200µA @ 5V	Not specified	0.6µA @ 1.3V ~ 1.8V	150µA @ 5.5V
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C
Time Format	HH:MM:SS (12/24 hr)	HH:MM:SS (12/24 hr)	HH:MM:SS (12/24 hr)	HH:MM:SS (24 hr)	HH:MM:SS:hh	HH:MM:SS (12/24 hr)	HH:MM:SS (12/24 hr)	HH:MM:SS (12/24 hr)	HH:MM:SS (24 hr)
Date Format	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd	YY-MM-DD-dd
Features	Alarm, Leap Year, Square Wave Output	Alarm, Leap Year	Alarm, Leap Year, Square Wave Output	Alarm, Leap Year, Square Wave Output	Alarm, Leap Year, SRAM, Trickle-Charger, Watchdog Timer	Leap Year, NVSRAM, Square Wave Output	Leap Year, NVSRAM, Square Wave Output	Alarm, Leap Year, Square Wave Output	Leap Year, Trickle-Charger
RoHS Status	Not specified	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited) / 2 (1 Year)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

For Direct Pin-Compatible Replacement (8-SOIC Package):

ISL12057IBZ and ISL12057IBZ-T are MFR recommended substitutes from Renesas Electronics Corporation. Both maintain the 8-SOIC package form factor and I2C interface. The ISL12057IBZ-T variant in Tape & Reel packaging offers higher inventory availability (4060 pcs) compared to tube packaging. Supply voltage range is 1.8V ~ 3.6V, which is narrower than the original part but covers low-power applications. Both are ROHS3 compliant and carry MSL 1 or MSL 2 ratings. Current consumption is comparable at 0.65µA @ 1.8V.

DS1337S+ and DS1337S+T&R from Analog Devices Inc./Maxim Integrated provide full electrical compatibility with the 1337DCGI8, including identical supply voltage range (1.8V ~ 5.5V), timekeeping current (0.6µA @ 1.3V ~ 1.8V), and feature set (Alarm, Leap Year, Square Wave Output). Both are ROHS3 compliant with MSL 1 rating. DS1337S+T&R offers significantly higher inventory (100,100 pcs) in Cut Tape & Digi-Reel packaging.

For Functional Equivalents with Alternative Packages:

AB-RTCMC-32.768KHZ-B5GA-S3-T (Abracon, 10-SMD Module) provides superior low-power performance (0.45µA ~ 0.55µA @ 2V ~ 5V) and extended supply voltage range (1.2V ~ 5.5V). Module packaging requires PCB layout adaptation but eliminates external crystal requirements.

AB1805-T3 (Abracon, 16-VFQFN) offers the lowest timekeeping current (0.17µA ~ 0.22µA @ 1.8V ~ 3V) with additional features including SRAM, Trickle-Charger, and Watchdog Timer. Supply voltage is 1.7V ~ 3.6V, suitable for battery-backed applications.

DS1307ZN+ (Analog Devices/Maxim, 8-SOIC) maintains package compatibility but requires minimum 4.5V supply and draws 200µA timekeeping current, making it suitable only for higher-power applications.

DS1308U-3+ (Analog Devices/Maxim, 8-TSSOP/MSOP) provides compact alternative packaging with supply range 2.7V ~ 5.5V and includes NVSRAM and Square Wave Output.

DS1337U+T&R (Analog Devices/Maxim, 8-TSSOP/MSOP) matches the 1337DCGI8 electrical specifications exactly (1.8V ~ 5.5V, 0.6µA @ 1.3V ~ 1.8V) in compact packaging with high inventory (11,200 pcs).

DS1340C-33#T&R (Analog Devices/Maxim, 16-SOIC) supports 24-hour time format only and requires minimum 2.97V supply with 150µA timekeeping current, suitable for applications with higher power budgets.

All substitute parts are ROHS3 compliant and carry REACH Unaffected status, matching the regulatory profile of the original part.

Frequently Asked Questions (FAQ)

Q: Can ISL12057IBZ be used as a direct replacement for 1337DCGI8?

A: ISL12057IBZ maintains the 8-SOIC package and I2C interface with compatible time/date formats and operating temperature range. However, the supply voltage range is narrower (1.8V ~ 3.6V vs. 1.8V ~ 5.5V). It is suitable for designs operating within 1.8V ~ 3.6V. The part lacks Square Wave Output feature present in the original.

Q: What is the difference between ISL12057IBZ and ISL12057IBZ-T?

A: Both parts are electrically identical. ISL12057IBZ is supplied in Tube packaging with MSL 1 rating, while ISL12057IBZ-T is supplied in Tape & Reel with MSL 2 (1 Year) rating. ISL12057IBZ-T offers higher inventory availability and is suitable for automated assembly processes.

Q: Is DS1337S+ a complete equivalent to 1337DCGI8?

A: DS1337S+ provides full electrical and functional equivalence: identical supply voltage (1.8V ~ 5.5V), timekeeping current (0.6µA @ 1.3V ~ 1.8V), package (8-SOIC), interface (I2C), and feature set (Alarm, Leap Year, Square Wave Output). It is the closest direct replacement.

Q: Why would I choose AB1805-T3 over DS1337S+?

A: AB1805-T3 offers significantly lower timekeeping current (0.17µA ~ 0.22µA vs. 0.6µA), making it superior for battery-backed applications. It includes additional features (SRAM, Trickle-Charger, Watchdog Timer) but requires PCB layout redesign due to 16-VFQFN package and narrower supply voltage range (1.7V ~ 3.6V).

Q: Can I use DS1307ZN+ as a substitute?

A: DS1307ZN+ maintains the 8-SOIC package and I2C interface but has significant limitations: minimum supply voltage is 4.5V (vs. 1.8V for the original), and timekeeping current is 200µA (vs. 0.6µA). It lacks the Alarm feature. Use only in applications with 4.5V ~ 5.5V supply and higher power budgets.

Q: What are the package options for substitutes?

A: Primary options are 8-SOIC (ISL12057IBZ, DS1337S+, DS1307ZN+), 8-TSSOP/MSOP (DS1308U-3+, DS1337U+T&R), 10-SMD Module (AB-RTCMC-32.768KHZ-B5GA-S3-T), 16-VFQFN (AB1805-T3), and 16-SOIC (DS1340C-33#T&R). 8-SOIC and 8-TSSOP/MSOP variants require minimal PCB layout changes.

Q: Are all substitutes ROHS3 compliant?

A: All listed substitute parts are ROHS3 compliant and carry REACH Unaffected status, matching regulatory requirements of the original 1337DCGI8.

Q: Which substitute has the best inventory availability?

A: DS1337S+T&R offers the highest inventory at 100,100 pcs in Cut Tape & Digi-Reel packaging, followed by DS1337U+T&R at 11,200 pcs and AB1805-T3 at 5,287 pcs.

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