S1ALH Equivalent & Substitute Parts

Part Overview

The S1ALH is a 1A, 50V standard recovery rectifier diode manufactured by Taiwan Semiconductor Corporation in SOD-123 surface mount packaging. This component is classified as not for new designs, indicating it has been superseded in the manufacturer's product portfolio. The part carries automotive-grade qualification (AEC-Q101) and is RoHS3 compliant. Due to its discontinued status for new applications, identification of functionally equivalent substitute components is necessary for ongoing maintenance, repair, and legacy system support.

Substiute Parts

S1ALH

Taiwan Semiconductor CorporationIn Stock: 1164S1ALH Datasheet

Current PartRFQ

S1DLWH

Taiwan Semiconductor CorporationIn Stock: 957S1DLWH Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the S1ALH is determined by the following critical electrical and mechanical parameters:

Mandatory Compatibility Criteria:

• Current rating: 1A average rectified current (Io)
• Forward voltage: 1.1V maximum at 1A
• Operating temperature range: -55°C to 175°C
• Mounting type: Surface mount
• Automotive qualification: AEC-Q101
• RoHS3 compliance

Voltage Rating Consideration: The S1ALH operates at 50V DC reverse voltage maximum. Substitute components may operate at equal or higher voltage ratings, as higher voltage-rated diodes function within lower voltage applications. The reverse voltage rating establishes the upper limit of circuit voltage the component can safely withstand.

Package Compatibility: The S1ALH uses SOD-123 packaging. Substitute parts must maintain surface mount compatibility and physical form factor consistency with the original design footprint.

The S1DLWH meets all mandatory criteria while providing a higher voltage rating (200V), making it a valid substitute for applications where the original 50V rating is sufficient.

Parameter Comparison

Engineering Selection Recommendations

S1DLWH as Primary Substitute:

The S1DLWH is the manufacturer-recommended substitute for the S1ALH. Both components share identical current ratings (1A), forward voltage characteristics (1.1V @ 1A), recovery speed classification, and thermal operating range (-55°C to 175°C). Both maintain automotive-grade qualification under AEC-Q101 and comply with RoHS3 and REACH requirements.

The S1DLWH provides a higher reverse voltage rating (200V versus 50V), which does not create incompatibility in applications designed for 50V operation. The higher voltage rating ensures the substitute component operates within safe margins in the original circuit environment.

The S1DLWH carries active product status, ensuring continued availability and manufacturing support, whereas the S1ALH is designated not for new designs. This status difference makes the S1DLWH the appropriate long-term component selection for replacement and repair applications.

Both components are surface mount devices with automotive qualification, supporting direct substitution in existing PCB designs without layout modification.

Frequently Asked Questions (FAQ)

Q: Can the S1DLWH directly replace the S1ALH in existing circuits?

A: Yes. The S1DLWH maintains identical current rating (1A), forward voltage (1.1V @ 1A), recovery speed, and operating temperature range as the S1ALH. The higher voltage rating (200V versus 50V) does not create functional incompatibility in applications designed for 50V operation.

Q: What is the significance of the higher voltage rating on the S1DLWH?

A: The S1DLWH's 200V reverse voltage rating exceeds the S1ALH's 50V rating. In circuit applications, the substitute component operates at the same voltage stress as the original part. The higher rating provides additional safety margin and does not alter electrical performance in the original application.

Q: Are both parts automotive-qualified?

A: Yes. Both the S1ALH and S1DLWH carry AEC-Q101 automotive qualification and are suitable for automotive applications requiring this certification level.

Q: What is the difference in reverse leakage current between these parts?

A: The S1ALH specifies 5 µA reverse leakage at 50V, while the S1DLWH specifies 1 µA reverse leakage at 200V. Leakage current is measured at the respective voltage ratings of each component. Both values are within acceptable ranges for standard recovery rectifier diodes.

Q: Are there package differences between the S1ALH and S1DLWH?

A: The S1ALH uses SOD-123 packaging, while the S1DLWH uses SOD-123W packaging. Both are surface mount packages with compatible footprints for PCB integration. Verify PCB layout compatibility with the specific package dimensions before implementation.

Q: Why is the S1ALH marked as not for new designs?

A: The S1ALH has been superseded in the manufacturer's product portfolio. The S1DLWH represents the current active alternative, offering equivalent electrical performance with enhanced voltage rating and continued manufacturing support.

Q: Are both components RoHS3 compliant?

A: Yes. Both the S1ALH and S1DLWH are RoHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for electronic components.