TLHR4400-AS21Z Equivalent & Substitute Parts

Part Overview

The TLHR4400-AS21Z is a red diffused LED in T-1 (3mm) through-hole package manufactured by Vishay Semiconductor Opto Division. This component is classified as obsolete, making substitute parts necessary for new designs and ongoing production requirements. The part delivers red light indication at 635nm peak wavelength with 13mcd brightness at 20mA test current and 2V forward voltage. Equivalent and substitute parts maintain the same core electrical and mechanical specifications while offering active product status and improved availability.

Substiute Parts

TLHR4400-AS21Z

Vishay Semiconductor Opto DivisionIn Stock: 902TLHR4400-AS21Z Datasheet

Current PartRFQ

TLHR4400-AS12Z

Vishay Semiconductor Opto DivisionIn Stock: 8429TLHR4400-AS12Z Datasheet

Parametric EquivalentRFQ

TLHR4400-MS12Z

Vishay Semiconductor Opto DivisionIn Stock: 10743TLHR4400-MS12Z Datasheet

Parametric EquivalentRFQ

TLHR4401-AS12Z

Vishay Semiconductor Opto DivisionIn Stock: 9839TLHR4401-AS12Z Datasheet

Parametric EquivalentRFQ

WP908A8ID

KingbrightIn Stock: 2897WP908A8ID Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts are classified into two categories based on parametric equivalence:

Parametric Equivalents (Vishay TLH.44 Series): TLHR4400-AS12Z, TLHR4400-MS12Z, and TLHR4401-AS12Z maintain identical electrical characteristics (2V forward voltage, 60° viewing angle, 3mm T-1 package, radial configuration) and mechanical dimensions (6.10mm maximum height). These parts differ in test current (10mA vs. 20mA) and millicandela rating (13-14mcd). All three are active products with ROHS3 compliance and superior inventory availability compared to the obsolete main part.

Direct Manufacturer Substitute (Kingbright WP908A8ID): This part shares the same color, lens style, package type, and forward voltage but operates at 20mA test current matching the original specification. It features a higher millicandela rating (20mcd) and wider viewing angle (80°), with slightly reduced maximum height (5.50mm vs. 6.10mm).

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Matching Test Current): WP908A8ID is the appropriate selection when the circuit design specifies 20mA test current operation. This Kingbright part maintains identical forward voltage and test current while providing higher brightness (20mcd) and wider viewing angle (80°). The 0.60mm reduction in maximum height presents no mechanical constraint for standard through-hole PCB layouts. All parts carry ROHS3 compliance and REACH unaffected status.

For Active Product Availability: TLHR4400-AS12Z and TLHR4400-MS12Z are preferred when maintaining the Vishay TLH.44 series is required. Both parts operate at reduced test current (10mA) with identical brightness and viewing angle specifications. TLHR4400-MS12Z offers the highest inventory level (10,677 pcs) among Vishay equivalents. TLHR4401-AS12Z provides marginally higher brightness (14mcd) at the same 10mA test current.

Compliance Verification: All substitute parts maintain ROHS3 compliance and REACH unaffected status, matching the original part's regulatory standing. No additional compliance documentation is required for substitution.

Frequently Asked Questions (FAQ)

Q: Can TLHR4400-AS12Z replace TLHR4400-AS21Z in existing designs? A: Yes. Both parts share identical forward voltage (2V), lens configuration (3mm T-1 diffused), viewing angle (60°), and mechanical dimensions (6.10mm height). The difference in test current (10mA vs. 20mA) does not affect circuit compatibility; the part will operate correctly at the original design current. Brightness remains constant at 13mcd.

Q: What is the difference between TLHR4400-AS12Z and TLHR4400-MS12Z? A: These parts are electrically and mechanically identical. Both are Vishay TLH.44 series red diffused LEDs with 2V forward voltage, 13mcd brightness, 60° viewing angle, and 6.10mm maximum height. The difference lies in packaging (Cut Tape) and inventory availability. TLHR4400-MS12Z has higher stock (10,677 pcs vs. 8,380 pcs).

Q: Why does WP908A8ID have different specifications? A: WP908A8ID is a Kingbright alternative that maintains core compatibility (red color, 2V forward voltage, 3mm T-1 package, through-hole mounting) while offering enhanced performance. It delivers 20mcd brightness (vs. 13mcd) and 80° viewing angle (vs. 60°), matching the original 20mA test current. The 0.60mm shorter height (5.50mm) is compatible with standard PCB layouts.

Q: Are all substitute parts RoHS compliant? A: Yes. TLHR4400-AS12Z, TLHR4400-MS12Z, TLHR4401-AS12Z, and WP908A8ID all carry ROHS3 compliance certification, matching the original part's regulatory status.

Q: Which substitute offers the best availability? A: TLHR4400-MS12Z provides the highest inventory level at 10,677 pieces in stock, followed by TLHR4401-AS12Z (9,788 pcs) and TLHR4400-AS12Z (8,380 pcs). WP908A8ID (Kingbright) has lower availability at 2,846 pieces.

Q: Can I use TLHR4401-AS12Z instead of TLHR4400-AS12Z? A: Yes. TLHR4401-AS12Z is functionally compatible with identical electrical and mechanical specifications except for a marginal brightness increase (14mcd vs. 13mcd). This higher brightness is not detrimental and may be beneficial in applications requiring enhanced visibility.