DS1744-70 Equivalent & Substitute Parts

Part Overview

The DS1744-70 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality and 32KB NVSRAM, manufactured by Analog Devices Inc./Maxim Integrated. This component operates in the 4.5V to 5.5V supply range and provides parallel interface connectivity for embedded timing applications. The DS1744-70 is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. Substitute components must maintain functional compatibility across time format, date format, interface type, and operating temperature specifications.

Substiute Parts

DS1744-70

Analog Devices Inc./Maxim IntegratedIn Stock: 2315DS1744-70 Datasheet

Current PartRFQ

DS1744-70+

Analog Devices Inc./Maxim IntegratedIn Stock: 1142DS1744-70+ Datasheet

DirectRFQ

BQ4802LYPW

Texas InstrumentsIn Stock: 9564BQ4802LYPW Datasheet

MFR RecommendedRFQ

DP8573AVX/NOPB

National SemiconductorIn Stock: 1484DP8573AVX/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the DS1744-70 are evaluated based on the following critical parameters that determine functional compatibility:

Primary Compatibility Criteria:

• Parallel interface connectivity
• Clock/Calendar functionality with matching time and date formats (HH:MM:SS and YY-MM-DD-dd)
• Operating temperature range compatibility (minimum 0°C ~ 70°C)
• Supply voltage compatibility or overlap with 4.5V ~ 5.5V range
• Through-hole or surface-mount packaging options for circuit board integration

Substitution Groups:

Group 1: Direct Pin-Compatible Replacement (Same Package)

• DS1744-70+ (Analog Devices Inc./Maxim Integrated): Active product status, identical electrical specifications, 28-DIP through-hole package, ROHS3 compliant

Group 2: Functional Equivalents (Different Package, Parallel Interface)

• BQ4802LYPW (Texas Instruments): Active product status, parallel interface, 28-TSSOP surface-mount package, extended feature set (Alarm, Daylight Savings, Watchdog Timer), operates at 2.7V ~ 3.6V supply range
• DP8573AVX/NOPB (National Semiconductor): Active product status, parallel interface, 28-LCC surface-mount package, extended operating temperature range (-40°C ~ 85°C), operates at 4.5V ~ 5.5V supply range

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred for Existing Designs): DS1744-70+ is the primary substitute for the obsolete DS1744-70. Both components share identical electrical specifications, time/date formats, parallel interface, and 28-DIP through-hole packaging. The DS1744-70+ maintains active product status and achieves ROHS3 compliance, making it suitable for new production runs and design continuity.

For New Designs with Surface-Mount Requirements: BQ4802LYPW (Texas Instruments) provides parallel interface Clock/Calendar functionality in a 28-TSSOP surface-mount package. This component operates at a lower supply voltage range (2.7V ~ 3.6V) and includes additional features (Alarm, Daylight Savings, Watchdog Timer). Circuit design modifications are required to accommodate the different supply voltage and package footprint.

For Extended Temperature Range Applications: DP8573AVX/NOPB (National Semiconductor) maintains the 4.5V ~ 5.5V supply voltage compatibility with the DS1744-70 and extends the operating temperature range to -40°C ~ 85°C. This component is packaged in 28-LCC surface-mount format and offers significantly lower timekeeping current (1µA @ 5V). Surface-mount assembly and board layout modifications are necessary.

Compliance Considerations: The DS1744-70 is RoHS non-compliant. For applications requiring RoHS compliance, DS1744-70+ and BQ4802LYPW both achieve ROHS3 certification. DP8573AVX/NOPB RoHS status is not specified in available documentation.

Frequently Asked Questions (FAQ)

Q: Can DS1744-70+ be used as a direct replacement for DS1744-70? A: Yes. DS1744-70+ is the direct equivalent, sharing identical electrical specifications, time/date formats, parallel interface, and 28-DIP through-hole package. No circuit modifications are required.

Q: What are the key differences between DS1744-70 and BQ4802LYPW? A: BQ4802LYPW operates at a different supply voltage range (2.7V ~ 3.6V versus 4.5V ~ 5.5V), uses surface-mount 28-TSSOP packaging instead of through-hole 28-DIP, and includes additional features (Alarm, Daylight Savings, Watchdog Timer). Circuit redesign is necessary for substitution.

Q: Is DP8573AVX/NOPB compatible with the DS1744-70 supply voltage? A: Yes. DP8573AVX/NOPB operates at 4.5V ~ 5.5V, matching the DS1744-70 supply voltage range. However, it uses surface-mount 28-LCC packaging and requires board layout modifications.

Q: Which substitute part has the lowest power consumption? A: DP8573AVX/NOPB has the lowest timekeeping current at 1µA @ 5V, compared to 4mA @ 5V for DS1744-70 and DS1744-70+, and 1.5mA (Typ) @ 2.7V ~ 3.6V for BQ4802LYPW.

Q: Can I use BQ4802LYPW in a 5V system? A: No. BQ4802LYPW operates at 2.7V ~ 3.6V supply voltage and is not rated for 5V operation. Circuit redesign with appropriate voltage regulation is required.

Q: What packaging considerations apply to each substitute? A: DS1744-70+ maintains through-hole 28-DIP packaging identical to the original. BQ4802LYPW and DP8573AVX/NOPB both require surface-mount assembly and different board footprints. Through-hole to surface-mount conversion requires PCB redesign.

Q: Are all substitute parts currently in active production? A: DS1744-70+ (Active), BQ4802LYPW (Active), and DP8573AVX/NOPB (Active) are all currently manufactured. The original DS1744-70 is obsolete.