2SD1691-O-BP NPN Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The 2SD1691-O-BP is an NPN bipolar junction transistor manufactured by Micro Commercial Co, rated for 60 V collector-emitter breakdown voltage and 5 A maximum collector current in a TO-126 through-hole package. This device is classified as obsolete, necessitating identification of active equivalent and substitute components for ongoing design support and production continuity. The part operates across an industrial temperature range of -55°C to 150°C and dissipates a maximum of 1.3 W.

Substiute Parts

2SD1691-O-BP

Micro Commercial CoIn Stock: 8702SD1691-O-BP Datasheet

Current PartRFQ

KSD1691GS

onsemiIn Stock: 5963KSD1691GS Datasheet

DirectRFQ

KSD1691YS

onsemiIn Stock: 1621KSD1691YS Datasheet

DirectRFQ

BD437TG

onsemiIn Stock: 1563BD437TG Datasheet

SimilarRFQ

BD439G

onsemiIn Stock: 1784BD439G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2SD1691-O-BP is determined by strict alignment of electrical and mechanical parameters. The primary substitution criteria are:

Direct Electrical Equivalents (Recommended):

• Voltage rating: 60 V minimum (Vce breakdown)
• Current rating: 5 A minimum (Ic max)
• Power dissipation: 1.3 W minimum
• Package: TO-126-3 through-hole configuration
• DC current gain (hFE): minimum 100 @ 2A, 1V

Parts meeting all these criteria are classified as direct equivalents and are preferred for drop-in replacement without circuit redesign.

Similar Functional Alternatives (Conditional):

• Voltage rating: 45 V or higher (Vce breakdown)
• Current rating: 4 A or higher (Ic max)
• Package: TO-126 through-hole configuration
• Product status: Active

These parts function in similar applications but require verification of circuit margin requirements due to reduced current or voltage ratings.

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalent Selection (Preferred):

KSD1691GS and KSD1691YS are direct electrical equivalents to the 2SD1691-O-BP. Both parts are manufactured by onsemi with active product status, ensuring long-term availability and supply chain stability. Both maintain the 60 V / 5 A electrical specification and TO-126-3 package configuration. KSD1691GS provides superior DC current gain (200 @ 2A, 1V) compared to the original specification (100 @ 2A, 1V), while KSD1691YS offers intermediate gain (160 @ 2A, 1V). Both parts are ROHS3 compliant and suitable for direct substitution without circuit modification.

Conditional Alternatives (Lower Current/Voltage Rating):

BD437TG and BD439G are similar functional alternatives with reduced electrical ratings. BD437TG is rated for 45 V / 4 A, while BD439G is rated for 60 V / 4 A. Both parts feature significantly higher power dissipation (36 W versus 1.3 W) and higher transition frequency (3 MHz). These parts are suitable only in applications where the reduced 4 A current rating does not exceed circuit requirements. BD439G maintains the 60 V voltage specification and is preferred over BD437TG when voltage margin is critical.

Compliance and Availability:

All substitute parts maintain ROHS3 compliance and are actively manufactured. KSD1691GS and KSD1691YS demonstrate superior inventory availability (5950 and 1520 units respectively) compared to the obsolete 2SD1691-O-BP (772 units). Selection should prioritize active-status parts to ensure production continuity.

Frequently Asked Questions (FAQ)

Q: Can KSD1691GS or KSD1691YS be used as direct replacements for 2SD1691-O-BP?

A: Yes. Both KSD1691GS and KSD1691YS are direct electrical equivalents. They maintain identical voltage (60 V), current (5 A), power (1.3 W), and package (TO-126-3) specifications. Both are active products from onsemi and require no circuit modification for substitution.

Q: What is the difference between KSD1691GS and KSD1691YS?

A: The primary difference is DC current gain (hFE). KSD1691GS specifies a minimum of 200 @ 2A, 1V, while KSD1691YS specifies 160 @ 2A, 1V. Both exceed the original 2SD1691-O-BP specification of 100 @ 2A, 1V. Selection between these parts depends on circuit bias network design and gain tolerance requirements.

Q: Why are BD437TG and BD439G listed as similar alternatives rather than direct equivalents?

A: BD437TG and BD439G have reduced maximum collector current ratings (4 A versus 5 A). BD437TG additionally has a reduced voltage rating (45 V versus 60 V). These parts are suitable only when circuit design margins accommodate the lower current specification. The higher power dissipation (36 W) indicates different thermal and mechanical design, requiring thermal management verification.

Q: Are all substitute parts RoHS compliant?

A: Yes. The 2SD1691-O-BP and all listed substitute parts (KSD1691GS, KSD1691YS, BD437TG, BD439G) are ROHS3 compliant, meeting environmental and regulatory requirements for electronic component manufacturing.

Q: What is the operating temperature range for substitute parts?

A: KSD1691GS and KSD1691YS specify a maximum junction temperature (TJ) of 150°C without explicit minimum temperature specification. BD437TG and BD439G specify the full range of -55°C to 150°C, matching the original 2SD1691-O-BP. For applications requiring the full -55°C to 150°C range, BD437TG or BD439G are preferred if current rating permits.

Q: Can I use BD439G instead of KSD1691GS in a new design?

A: BD439G is suitable only if circuit design accommodates the 4 A maximum current rating (versus 5 A for KSD1691GS). BD439G offers higher power dissipation capability (36 W) and transition frequency (3 MHz), making it suitable for higher-frequency switching applications. Direct substitution requires verification that the 4 A current specification does not exceed circuit requirements.

Q: What packaging considerations apply to these substitute parts?

A: All parts use the TO-126-3 through-hole package with identical mechanical dimensions and pin configuration. PCB layout and thermal management design remain unchanged. No mechanical redesign is required for substitution.