PS720C-1A-A Solid State Relay SPST-NO Equivalent & Substitute Parts

Part Overview

The PS720C-1A-A is a Surface Mount Solid State Relay (SSR) manufactured by CEL, configured as a SPST-NO (Single Pole Single Throw - Normally Open) relay in a 4-SOP package. This component is designed for switching applications with AC and DC loads up to 60V and 1.25A maximum load current.

The PS720C-1A-A is classified as an Obsolete product. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or maintenance requirements for systems utilizing this component.

Substiute Parts

PS720C-1A-A

CELIn Stock: 1181PS720C-1A-A Datasheet

Current PartRFQ

TLP3122(F)

Toshiba Semiconductor and StorageIn Stock: 859TLP3122(F) Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PS720C-1A-A is determined by strict alignment of the following critical parameters:

Circuit Configuration: Both the main part and substitute must be SPST-NO (1 Form A) relays to maintain identical switching functionality.

Package and Mounting: The 4-SOP (0.173", 4.40mm) Surface Mount package with Gull Wing termination is a mandatory requirement for PCB compatibility and assembly process alignment.

Electrical Load Specifications: The substitute must support the same load voltage range (0 V ~ 60 V) and AC/DC output capability. Load current capacity must be equal to or greater than 1.25A to ensure the substitute can handle the design's maximum current requirements.

Input Voltage: The substitute input voltage specification must be compatible with the control circuit driving the relay. The PS720C-1A-A operates at 1.1 VDC input.

On-State Resistance: This parameter directly affects power dissipation and thermal performance. Substitutes with equal or lower on-state resistance maintain or improve thermal characteristics.

Moisture Sensitivity and Compliance: MSL rating and regulatory compliance (REACH, RoHS) ensure the substitute meets environmental and manufacturing standards applicable to the original design.

Parameter Comparison

Engineering Selection Recommendations

TLP3122(F) (Toshiba Semiconductor and Storage) is identified as a substitute for the PS720C-1A-A based on matching circuit configuration, package specifications, and load voltage range.

Product Status Advantage: The TLP3122(F) is classified as Active, ensuring ongoing availability and supply chain support, which addresses the obsolescence status of the PS720C-1A-A.

Compliance Status: The TLP3122(F) is RoHS Compliant, meeting current environmental and manufacturing regulations. Both parts are REACH Affected and carry the same ECCN and HTSUS classifications.

Critical Electrical Differences: The TLP3122(F) has a maximum load current rating of 1A compared to the PS720C-1A-A's 1.25A, and an on-state resistance of 250 mOhms versus 190 mOhms. These differences must be evaluated against the actual application requirements. If the design operates at or near 1.25A, the substitute's 1A rating may be insufficient. The higher on-state resistance of the substitute will result in increased power dissipation and heat generation.

Input Voltage Compatibility: The TLP3122(F) input voltage of 1.15 VDC is marginally higher than the PS720C-1A-A's 1.1 VDC specification. This difference is within typical control circuit tolerances and does not present a compatibility barrier.

Selection Criteria: Choose the TLP3122(F) when application load current is confirmed to be 1A or below and thermal dissipation from the higher on-state resistance is acceptable. For applications requiring the full 1.25A capacity or lower thermal dissipation, alternative substitutes should be evaluated.

Frequently Asked Questions (FAQ)

Q: Why is the PS720C-1A-A classified as obsolete?

A: The PS720C-1A-A is no longer in active production by CEL. Obsolete status indicates the manufacturer has discontinued this product line. Identifying active substitutes ensures continued availability for new designs and replacement components for existing systems.

Q: Can the TLP3122(F) be used as a direct replacement in all applications?

A: The TLP3122(F) is electrically and mechanically compatible with the PS720C-1A-A in terms of package, circuit configuration, and load voltage range. However, the lower maximum load current (1A vs. 1.25A) and higher on-state resistance (250 mOhms vs. 190 mOhms) require verification against specific application requirements. Direct replacement is valid only when application current does not exceed 1A and thermal performance is acceptable.

Q: What is the significance of the 4-SOP package specification?

A: The 4-SOP (Small Outline Package) with 0.173" (4.40mm) body size and Gull Wing termination is a standardized Surface Mount package. This specification ensures mechanical and electrical compatibility with existing PCB layouts, solder reflow processes, and automated assembly equipment. Substitutes must use the identical package to maintain design integrity.

Q: How do input voltage differences affect substitution?

A: The PS720C-1A-A operates at 1.1 VDC input, while the TLP3122(F) operates at 1.15 VDC. This 0.05 VDC difference is minimal and typically within the tolerance of control circuits. Both specifications are compatible with standard logic-level control signals (3.3V or 5V). Input voltage differences become critical only in precision analog control applications, which is not the case for standard relay switching.

Q: What does MSL 1 (Unlimited) mean for moisture sensitivity?

A: MSL 1 (Moisture Sensitivity Level 1) with Unlimited rating indicates the component has minimal sensitivity to moisture absorption during storage and handling. Both the PS720C-1A-A and TLP3122(F) carry this rating, meaning standard storage conditions and handling procedures are sufficient. No special dry-pack or desiccant requirements apply.

Q: Are there compliance or regulatory differences between these parts?

A: Both parts carry identical ECCN (EAR99) and HTSUS (8536.41.0030) classifications. The TLP3122(F) is explicitly RoHS Compliant, while the PS720C-1A-A status is not specified. Both are REACH Affected. For new designs or applications with RoHS requirements, the TLP3122(F) is the preferred choice.

Q: How does on-state resistance affect circuit performance?

A: On-state resistance determines the voltage drop across the relay when conducting current. The PS720C-1A-A has 190 mOhms maximum, while the TLP3122(F) has 250 mOhms maximum. At 1A load current, this results in a voltage drop of 0.19V versus 0.25V respectively. Higher resistance also increases power dissipation as heat. For applications sensitive to voltage drop or operating in thermally constrained environments, the lower resistance of the PS720C-1A-A is advantageous.

Q: What inventory status should influence the selection decision?

A: The PS720C-1A-A has 1082 pieces in stock (New Original), while the TLP3122(F) has 797 pieces available. For immediate procurement, the PS720C-1A-A offers greater availability. However, the PS720C-1A-A is obsolete and stock is finite. For long-term production or future designs, the TLP3122(F) is the sustainable choice due to its Active status and ongoing manufacturing support.