LCA211STR Equivalent & Substitute Parts

Part Overview

The LCA211STR is a solid-state relay (SSR) manufactured by Littelfuse in the OptoMOS® series. It functions as a SPST-NO (Single Pole Single Throw - Normally Open) relay with dual channels in an 8-SMD surface mount package. The device is rated for 85 mA load current across 0–350 V AC/DC output voltage with 1.2 VDC input control voltage.

This part is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or maintenance requirements for systems using this component.

Substiute Parts

LCA211STR

LittelfuseIn Stock: 1480LCA211STR Datasheet

Current PartRFQ

AQW210EHAZ

Panasonic Electric WorksIn Stock: 3957AQW210EHAZ Datasheet

MFR RecommendedRFQ

AQW610EHAZ

Panasonic Electric WorksIn Stock: 3111AQW610EHAZ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LCA211STR is determined by the following critical parameters:

• Circuit Configuration: SPST-NO (1 Form A) x 2 dual-channel architecture
• Package / Case: 8-SMD (0.300", 7.62mm) with Gull Wing termination
• Voltage Rating: Load voltage range 0–350 V AC/DC
• Input Control Voltage: Compatibility with 1.2 VDC or lower input threshold
• Load Current Capability: Minimum 85 mA rated current
• On-State Resistance: Maximum 35 Ohms
• Mounting Type: Surface Mount

Two substitute parts meet these criteria:

AQW210EHAZ (Panasonic Electric Works, PhotoMOS™ AQW series) – Dual SPST-NO configuration matching the original circuit topology. Active product status with higher load current rating (120 mA) and lower on-state resistance (25 Ohms). Input voltage 1.14 VDC is compatible with the original 1.2 VDC specification.

AQW610EHAZ (Panasonic Electric Works, PhotoMOS™ AQW series) – Dual configuration with SPST-NO + SPST-NC (1 Form A and B) providing additional switching capability. Active product status with 120 mA load current and 25 Ohms on-state resistance. Input voltage 1.14 VDC is compatible. Note: This part provides Form B (NC) in addition to Form A (NO), expanding functional capability beyond the original part.

Parameter Comparison

Engineering Selection Recommendations

AQW210EHAZ is the direct functional equivalent for applications requiring SPST-NO dual-channel operation. This part maintains identical circuit topology to the LCA211STR while offering improved electrical performance (higher load current, lower on-state resistance) and active product status ensuring long-term availability and supply chain support.

AQW610EHAZ provides expanded functionality with dual SPST-NO + SPST-NC configuration. Selection of this part is appropriate only when the additional Form B (NC) switching capability can be utilized or when the design can accommodate the expanded functionality without circuit modification. Both substitute parts are ROHS3 compliant and REACH unaffected, meeting modern regulatory requirements.

The obsolete status of the LCA211STR makes transition to an active substitute part necessary for new production or ongoing supply requirements. Both Panasonic PhotoMOS™ alternatives are actively manufactured and widely available.

Frequently Asked Questions (FAQ)

Q: Can AQW210EHAZ directly replace LCA211STR in existing designs?

A: Yes. AQW210EHAZ maintains identical circuit configuration (SPST-NO x 2), package (8-SMD Gull Wing), voltage ratings (0–350 V load, 1.14 VDC input), and mounting type. The lower input voltage (1.14 VDC vs. 1.2 VDC) and improved electrical performance (120 mA vs. 85 mA, 25 Ohms vs. 35 Ohms) are compatible with designs using the original part.

Q: What is the difference between AQW210EHAZ and AQW610EHAZ?

A: AQW210EHAZ provides dual SPST-NO (Form A) channels matching the original LCA211STR topology. AQW610EHAZ provides one SPST-NO (Form A) and one SPST-NC (Form B) channel per package. Both share identical voltage ratings, load current, on-state resistance, and package specifications. Selection depends on whether Form B (NC) functionality is required.

Q: Are the substitute parts pin-compatible with LCA211STR?

A: Both AQW210EHAZ and AQW610EHAZ use the same 8-SMD (0.300", 7.62mm) package with Gull Wing termination as the LCA211STR. Pin compatibility must be verified against specific PCB layout and schematic requirements, as circuit configuration differences (particularly AQW610EHAZ with Form B) may affect pin assignment.

Q: What compliance certifications apply to the substitute parts?

A: Both AQW210EHAZ and AQW610EHAZ are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic components in most markets.

Q: Is the lower input voltage of the substitute parts (1.14 VDC vs. 1.2 VDC) a concern?

A: No. The 1.14 VDC input specification of both substitute parts is lower than the original 1.2 VDC, meaning they trigger at a lower control voltage. This provides improved sensitivity and is compatible with designs using the original part's 1.2 VDC specification.