DS1557P-70+ Equivalent & Substitute Parts Reference

Part Overview

The DS1557P-70+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This device provides 512KB of parallel interface memory with comprehensive timekeeping features including alarm, leap year compensation, non-volatile SRAM (NVSRAM), watchdog timer, and Y2K compliance. The part is currently in active production status with 1414 units in stock.

Substitute parts are identified when equivalent functional performance can be achieved within the allowed electrical and mechanical parameter ranges for RTC Clock/Calendar applications. Substitution becomes necessary due to component availability, supply chain constraints, or design revision requirements.

Substiute Parts

DS1557P-70+

Analog Devices Inc./Maxim IntegratedIn Stock: 1516DS1557P-70+ Datasheet

Current PartRFQ

BQ4802LYPW

Texas InstrumentsIn Stock: 9564BQ4802LYPW Datasheet

MFR RecommendedRFQ

M48T201V-85MH1F

STMicroelectronicsIn Stock: 1609M48T201V-85MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the DS1557P-70+ are qualified based on the following critical parameters:

Functional Compatibility Criteria:

• Category: Clock/Timing
• Type: Clock/Calendar
• Interface: Parallel
• Time Format: HH:MM:SS with 24-hour capability
• Date Format: YY-MM-DD-dd
• Features: Alarm and Watchdog Timer (minimum required)
• Operating Temperature Range: 0°C ~ 70°C (minimum overlap)
• Mounting Type: Surface Mount
• RoHS Status: ROHS3 Compliant

Electrical Parameter Ranges:

• Supply voltage must support operation within or overlap with 4.5V ~ 5.5V or provide battery-backed operation at 3V
• Current consumption in timekeeping mode must be documented
• Battery supply voltage must support 3V operation

Mechanical Compatibility:

• Surface mount package with documented pin configuration
• Moisture sensitivity level acceptable for standard handling (MSL 1-3)

The identified substitute parts meet these criteria while maintaining functional equivalence for RTC Clock/Calendar applications requiring parallel interface operation.

Parameter Comparison

Engineering Selection Recommendations

DS1557P-70+ Primary Application: The DS1557P-70+ operates at 4.5V ~ 5.5V supply voltage with 512KB memory capacity. This device is suitable for systems requiring higher supply voltage operation with integrated NVSRAM functionality. All three parts maintain active product status and ROHS3 compliance.

BQ4802LYPW Substitution Considerations: The BQ4802LYPW operates at reduced supply voltage (2.7V ~ 3.6V) with lower timekeeping current consumption (1.5mA typical). This part is applicable to low-power system designs. Package differs (28-TSSOP versus 34-PowerCap™ Module), requiring PCB layout modification. MSL rating of 1 provides superior moisture handling characteristics.

M48T201V-85MH1F Substitution Considerations: The M48T201V-85MH1F operates at 3V ~ 3.6V supply voltage with 2mA timekeeping current. This device includes square wave output functionality and supervisor features. Package differs (44-BSOP versus 34-PowerCap™ Module), requiring PCB layout modification. MSL rating of 3 matches the primary part. The 44-BSOP package requires SNAPHAT connector.

Compliance Status: All three parts maintain ROHS3 compliance and REACH unaffected status, suitable for regulated applications. All parts are classified under ECCN EAR99 and HTSUS 8542.39.

Frequently Asked Questions (FAQ)

Q: Can BQ4802LYPW directly replace DS1557P-70+ without PCB modification?

A: No. The BQ4802LYPW uses 28-TSSOP package while DS1557P-70+ uses 34-PowerCap™ Module package. Pin count and layout differ, requiring PCB redesign. Additionally, supply voltage range differs (2.7V ~ 3.6V versus 4.5V ~ 5.5V), necessitating power supply circuit modification.

Q: What are the key electrical differences between these parts?

A: DS1557P-70+ requires 4.5V ~ 5.5V supply with 6mA timekeeping current. BQ4802LYPW operates at 2.7V ~ 3.6V with 1.5mA typical current, offering lower power consumption. M48T201V-85MH1F operates at 3V ~ 3.6V with 2mA current. All three support 3V battery backup operation.

Q: Are all substitute parts suitable for the same operating temperature range?

A: Yes. All three parts operate across 0°C ~ 70°C, matching the primary part's temperature specification.

Q: What is the significance of MSL rating differences?

A: DS1557P-70+ and M48T201V-85MH1F both have MSL 3 (168 hours), requiring controlled storage and handling. BQ4802LYPW has MSL 1 (unlimited), allowing standard storage without moisture control requirements. MSL rating affects component shelf life and handling procedures.

Q: Do all parts support 24-hour time format?

A: DS1557P-70+ and M48T201V-85MH1F both support 24-hour format exclusively. BQ4802LYPW supports both 12-hour and 24-hour formats, providing additional flexibility for system design.

Q: What features are common across all three parts?

A: All three parts include Alarm, Leap Year compensation, and Watchdog Timer functionality. All maintain parallel interface operation and support YY-MM-DD-dd date format. All are ROHS3 compliant and active production status.

Q: Are there memory size differences between substitute parts?

A: Memory size is not specified for BQ4802LYPW and M48T201V-85MH1F in the provided data. DS1557P-70+ specifies 512KB memory. Verify memory requirements for your application before substitution.