LAA125 Solid State Relay - Equivalent & Substitute Parts

Part Overview

The LAA125 is an OptoMOS® solid state relay manufactured by IXYS Integrated Circuits Division, configured as a SPST-NO (1 Form A) dual relay in an 8-DIP through-hole package. This component is designed for AC and DC load switching applications with a maximum load voltage of 350V and rated load current of 170mA. The part is currently active in production and ROHS3 compliant. Equivalent and substitute parts are identified when design requirements necessitate alternative sourcing, inventory constraints, or performance parameter adjustments within acceptable operating ranges.

Substiute Parts

LAA125

IXYS Integrated Circuits DivisionIn Stock: 2111LAA125 Datasheet

Current PartRFQ

AQW210EH

Panasonic Electric WorksIn Stock: 19047AQW210EH Datasheet

MFR RecommendedRFQ

LH1520AB

Vishay Semiconductor Opto DivisionIn Stock: 7410LH1520AB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LAA125 are qualified based on the following critical parameters that determine functional interchangeability:

Mandatory Compatibility Parameters:

• Circuit configuration: SPST-NO (1 Form A) x 2
• Package type: 8-DIP (0.300", 7.62mm)
• Mounting type: Through Hole
• Load voltage range: 0V ~ 350V
• Output type: AC, DC capable
• Termination style: PC Pin

Performance Parameters (within acceptable operating ranges):

• Input voltage: 1.14VDC to 1.26VDC (tolerance band around 1.2VDC nominal)
• Load current: 110mA to 170mA (minimum 110mA required for most applications)
• On-state resistance: 16 to 25 Ohms (affects power dissipation and voltage drop)

The identified substitutes AQW210EH and LH1520AB meet all mandatory compatibility requirements and operate within acceptable performance parameter ranges for direct replacement in the LAA125 application space.

Parameter Comparison

Engineering Selection Recommendations

All three parts—LAA125, AQW210EH, and LH1520AB—maintain active production status and ROHS3 compliance, ensuring long-term availability and regulatory alignment. Selection between these parts is determined by application-specific load current requirements and acceptable on-state resistance characteristics.

The LAA125 provides the highest load current rating at 170mA with the lowest on-state resistance at 16 Ohms, making it suitable for applications requiring maximum current capacity and minimal power dissipation.

The AQW210EH (Panasonic PhotoMOS™) operates at 120mA load current with 25 Ohms on-state resistance. This part is appropriate for applications where load current does not exceed 120mA and where the higher on-state resistance is acceptable for the thermal budget.

The LH1520AB (Vishay) provides 110mA load current with 20 Ohms on-state resistance, positioning it as an intermediate option between the LAA125 and AQW210EH for applications requiring moderate current handling with controlled power dissipation.

Input voltage specifications across all three parts (1.14VDC to 1.26VDC) are compatible with standard 1.2VDC control circuits, ensuring consistent drive requirements across substitution options.

Frequently Asked Questions (FAQ)

Q: Can AQW210EH replace LAA125 in all applications?

A: AQW210EH is a direct substitute only for applications where load current does not exceed 120mA. The LAA125 is rated for 170mA; applications requiring the full 170mA load current must use the LAA125 or verify that the AQW210EH's 120mA rating is sufficient for the specific load.

Q: What is the impact of on-state resistance differences between these parts?

A: On-state resistance directly affects power dissipation and voltage drop across the relay output. The LAA125 (16 Ohms) dissipates less power than AQW210EH (25 Ohms) or LH1520AB (20 Ohms) at equivalent load currents. Applications with tight thermal budgets or high-frequency switching should prioritize lower on-state resistance values.

Q: Are all three parts pin-compatible?

A: Yes. All three parts use the 8-DIP (0.300", 7.62mm) package with PC pin termination, ensuring mechanical and electrical pin compatibility for through-hole PCB mounting.

Q: Do input voltage differences affect circuit design?

A: Input voltage specifications (1.2VDC nominal for LAA125, 1.14VDC for AQW210EH, 1.26VDC for LH1520AB) fall within a narrow tolerance band. Standard 1.2VDC control circuits will operate all three parts reliably without design modification.

Q: Which part should be selected for new designs?

A: Selection depends on load current requirements. For applications requiring 170mA capacity, specify LAA125. For applications with 120mA or lower load current, AQW210EH or LH1520AB are acceptable alternatives. Verify load current specifications against application requirements before final selection.

Q: Are all parts suitable for both AC and DC load switching?

A: Yes. All three parts support AC and DC output types across the 0V to 350V load voltage range, providing flexibility for diverse switching applications.