DS1307Z Real Time Clock IC Equivalent & Substitute Parts

Part Overview

The DS1307Z is a Real Time Clock (RTC) IC manufactured by Analog Devices Inc./Maxim Integrated, designed for clock/calendar applications with I2C serial interface. This 8-SOIC package device provides 56 bytes of non-volatile SRAM, leap year support, and square wave output capability. The DS1307Z is currently listed as obsolete, making equivalent and substitute parts necessary for new designs and production continuity. Active alternatives with compatible or enhanced specifications are available from multiple manufacturers including Renesas Electronics Corporation.

Key Parameters

Parameter	DS1307Z
Manufacturer	Analog Devices Inc./Maxim Integrated
Package / Case	8-SOIC (0.154", 3.90mm Width)
Memory Size	56B
Interface	I2C, 2-Wire Serial
Time Format	HH:MM:SS (12/24 hr)
Date Format	YY-MM-DD-dd
Voltage - Supply	4.5V ~ 5.5V
Voltage - Supply, Battery	2V ~ 4.6V
Current - Timekeeping (Max)	200µA @ 5V
Operating Temperature	0°C ~ 70°C
Features	Leap Year, NVSRAM, Square Wave Output
Product Status	Obsolete
RoHS Status	RoHS non-compliant

Substitute Part Grouping Explanation

Substitution for the DS1307Z is determined by the following critical parameters:

Primary Compatibility Criteria:

Package type (8-SOIC preferred for direct PCB compatibility)
I2C/2-Wire Serial interface requirement
Memory size (56B minimum for NVSRAM applications)
Time and date format support (HH:MM:SS 12/24hr, YY-MM-DD-dd)
Supply voltage range compatibility (minimum 4.5V ~ 5.5V or broader range)
Operating temperature range (minimum 0°C ~ 70°C or broader)

Substitution Groups:

Group 1: Direct Package Equivalents (8-SOIC) Parts maintaining identical 8-SOIC packaging with 56B NVSRAM and full feature parity: DS1307Z+, 1338-31DCGI, 1338-31DCGI8

Group 2: Enhanced Alternatives (8-SOIC with Extended Specifications) Parts in 8-SOIC package with 56B memory but extended operating temperature and lower supply voltage minimums: 1338-31DCGI, 1338-31DCGI8

Group 3: Compact Package Alternatives (8-MSOP/8-TSSOP) Functionally equivalent parts in smaller 8-MSOP/8-TSSOP packages: 1337DVGI8, 1337GDVGI8, 1338-31DVGI8, ISL12057IUZ-T

Group 4: Extended Memory Alternatives (20-SOIC) Parts with expanded 128B memory and additional features in larger package: ISL12022MIBZ-T, ISL12022MIBZR5421

Group 5: Specialized Compact (8-TDFN) Obsolete alternative in ultra-compact package: ISL1208IRT8Z

Parameter Comparison

Part Number	Manufacturer	Package	Memory Size	Interface	Supply Voltage	Battery Voltage	Current - Timekeeping (Max)	Operating Temp	Product Status	RoHS Status
DS1307Z	Analog Devices Inc./Maxim Integrated	8-SOIC	56B	I2C, 2-Wire Serial	4.5V ~ 5.5V	2V ~ 4.6V	200µA @ 5V	0°C ~ 70°C	Obsolete	RoHS non-compliant
DS1307Z+	Analog Devices Inc./Maxim Integrated	8-SOIC	56B	I2C, 2-Wire Serial	4.5V ~ 5.5V	2V ~ 4.6V	200µA @ 5V	0°C ~ 70°C	Active	ROHS3 Compliant
1338-31DCGI8	Renesas Electronics Corporation	8-SOIC	56B	I2C, 2-Wire Serial	3.3V ~ 5.5V	1.3V ~ 3.7V	5µA @ 3.63V ~ 5.5V	-40°C ~ 85°C	Active	ROHS3 Compliant
1338-31DCGI	Renesas Electronics Corporation	8-SOIC	56B	I2C, 2-Wire Serial	3.3V ~ 5.5V	1.3V ~ 3.7V	5µA @ 3.63V ~ 5.5V	-40°C ~ 85°C	Active	ROHS3 Compliant
1337DVGI8	Renesas Electronics Corporation	8-TSSOP, 8-MSOP	—	I2C, 2-Wire Serial	1.8V ~ 5.5V	—	0.6µA @ 1.3V ~ 1.8V	-40°C ~ 85°C	Active	ROHS3 Compliant
1337GDVGI8	Renesas Electronics Corporation	8-TSSOP, 8-MSOP	—	I2C, 2-Wire Serial	1.8V ~ 5.5V	—	0.6µA @ 1.3V ~ 1.8V	-40°C ~ 85°C	Active	ROHS3 Compliant
1338-31DVGI8	Renesas Electronics Corporation	8-TSSOP, 8-MSOP	56B	I2C, 2-Wire Serial	3.3V ~ 5.5V	1.3V ~ 3.7V	5µA @ 3.63V ~ 5.5V	-40°C ~ 85°C	Active	ROHS3 Compliant
ISL12022MIBZ-T	Renesas Electronics Corporation	20-SOIC	128B	I2C, 2-Wire Serial	2.7V ~ 5.5V	1.8V ~ 5.5V	14µA ~ 15µA @ 3V ~ 5V	-40°C ~ 85°C	Active	ROHS3 Compliant
ISL12022MIBZR5421	Renesas Electronics Corporation	20-SOIC	128B	I2C, 2-Wire Serial	2.7V ~ 5.5V	1.8V ~ 5.5V	14µA ~ 15µA @ 3V ~ 5V	-40°C ~ 85°C	Active	ROHS3 Compliant
ISL12057IUZ-T	Renesas Electronics Corporation	8-TSSOP, 8-MSOP	—	I2C, 2-Wire Serial	1.8V ~ 3.6V	—	0.65µA @ 1.8V	-40°C ~ 85°C	Active	ROHS3 Compliant
ISL1208IRT8Z	Renesas Electronics Corporation	8-WDFN Exposed Pad	2B	I2C, 2-Wire Serial	2.7V ~ 5.5V	1.8V ~ 5.5V	4µA ~ 6µA @ 3V ~ 5V	-40°C ~ 85°C	Obsolete	ROHS3 Compliant

Engineering Selection Recommendations

For Direct Replacement (Identical Package and Footprint):

DS1307Z+ is the primary direct substitute, maintaining 8-SOIC packaging, 56B NVSRAM, and identical electrical specifications while offering active product status and ROHS3 compliance. This part provides the lowest risk migration path for existing designs.

1338-31DCGI8 and 1338-31DCGI offer enhanced specifications within the same 8-SOIC package, including extended operating temperature range (-40°C ~ 85°C versus 0°C ~ 70°C), lower supply voltage minimum (3.3V versus 4.5V), and significantly reduced timekeeping current (5µA versus 200µA). Both are ROHS3 compliant and active products.

For Space-Constrained Designs:

1338-31DVGI8 provides 56B NVSRAM functionality in a compact 8-MSOP package with extended temperature range and reduced power consumption. This option requires PCB layout modification but maintains full feature compatibility.

1337DVGI8 and 1337GDVGI8 offer ultra-low power operation (0.6µA timekeeping current) in 8-MSOP packages with extended voltage range (1.8V ~ 5.5V), suitable for battery-powered applications. Memory size is not specified for these parts.

For Extended Memory Requirements:

ISL12022MIBZ-T and ISL12022MIBZR5421 provide 128B memory in 20-SOIC packages with alarm and daylight savings features. These parts require larger PCB footprint but offer expanded functionality and active product status.

For Ultra-Compact Applications:

ISL12057IUZ-T delivers minimal power consumption (0.65µA) in 8-MSOP package with restricted voltage range (1.8V ~ 3.6V), suitable for low-voltage battery-backed systems.

Compliance Considerations:

All recommended active substitutes are ROHS3 compliant, addressing the RoHS non-compliance status of the original DS1307Z. The DS1307Z+ maintains identical specifications while achieving ROHS3 compliance, making it the preferred choice for regulatory compliance requirements.

Frequently Asked Questions (FAQ)

Q: Can DS1307Z+ be used as a direct drop-in replacement for DS1307Z?

A: Yes. DS1307Z+ maintains identical package (8-SOIC), pinout, memory size (56B), interface (I2C 2-Wire Serial), supply voltage range (4.5V ~ 5.5V), and operating temperature range (0°C ~ 70°C). The primary difference is active product status and ROHS3 compliance. No PCB modifications are required.

Q: What are the key differences between 1338-31DCGI8 and DS1307Z?

A: Both use 8-SOIC packaging and provide 56B NVSRAM with I2C interface. The 1338-31DCGI8 offers extended operating temperature (-40°C ~ 85°C), lower supply voltage minimum (3.3V), lower battery voltage minimum (1.3V), and significantly reduced timekeeping current (5µA versus 200µA). The 1338-31DCGI8 is ROHS3 compliant and active.

Q: Can I use 1338-31DVGI8 if my PCB is designed for 8-SOIC packages?

A: No. The 1338-31DVGI8 uses 8-MSOP package (0.118" width) versus 8-SOIC (0.154" width). While both are 8-pin surface mount packages, the pinout and footprint differ. PCB layout modification is required.

Q: What is the advantage of ISL12022MIBZ-T over DS1307Z?

A: ISL12022MIBZ-T provides 128B memory (versus 56B), alarm functionality, daylight savings support, and extended operating temperature range (-40°C ~ 85°C). Supply voltage range is broader (2.7V ~ 5.5V). The trade-off is larger 20-SOIC package requiring PCB redesign.

Q: Are there low-power alternatives to DS1307Z?

A: Yes. 1338-31DCGI8 reduces timekeeping current to 5µA (40x reduction). 1337DVGI8, 1337GDVGI8, and ISL12057IUZ-T offer ultra-low power (0.6µA ~ 0.65µA) but in compact 8-MSOP packages and with different memory specifications. Selection depends on voltage range and memory requirements.

Q: Which substitute is best for new designs requiring RoHS compliance?

A: All active substitutes listed are ROHS3 compliant. For identical specifications with compliance, use DS1307Z+. For enhanced performance and compliance, use 1338-31DCGI8 or 1338-31DCGI in 8-SOIC package.

Q: Can I use parts with unspecified memory size as DS1307Z replacements?

A: No. 1337DVGI8, 1337GDVGI8, and ISL12057IUZ-T do not specify memory size in the provided data. If 56B NVSRAM is required for your application, these parts are not suitable substitutes.

Q: What packaging options are available for 56B NVSRAM RTC functionality?

A: 56B NVSRAM RTC functionality is available in three packages: 8-SOIC (DS1307Z+, 1338-31DCGI, 1338-31DCGI8), 8-MSOP (1338-31DVGI8), and 20-SOIC (ISL12022 series with 128B memory). Package selection depends on PCB space constraints and design requirements.

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