D45C12G PNP Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The D45C12G is an obsolete PNP bipolar junction transistor manufactured by onsemi, rated for 80V collector-emitter breakdown voltage and 4A maximum collector current in a TO-220 through-hole package. The device is designed for 30W power dissipation applications with a 40MHz transition frequency and operates across a temperature range of -55°C to 150°C.

Due to its obsolete product status, locating original D45C12G units presents supply chain challenges. Equivalent and substitute parts are necessary to maintain design continuity and ensure project completion. The following alternatives provide comparable electrical and mechanical characteristics suitable for direct replacement or design adaptation.

Substiute Parts

D45C12G

onsemiIn Stock: 727D45C12G Datasheet

Current PartRFQ

KSB596YTU

onsemiIn Stock: 1752KSB596YTU Datasheet

DirectRFQ

TIP42BG

onsemiIn Stock: 2140TIP42BG Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the D45C12G is determined by the following critical parameters:

Primary Compatibility Criteria:

• Transistor Type: PNP configuration
• Voltage - Collector Emitter Breakdown: minimum 80V
• Current - Collector (Ic) (Max): minimum 4A
• Package / Case: TO-220-3 through-hole mounting
• Power - Max: minimum 30W

Substitution Logic:

The KSB596YTU qualifies as a direct manufacturer equivalent. It maintains identical voltage and current ratings (80V, 4A), equivalent power dissipation (30W), and identical TO-220-3 packaging. Although transition frequency is reduced to 3MHz and saturation voltage characteristics differ, the part satisfies all primary electrical and mechanical compatibility requirements.

The TIP42BG is classified as a similar substitute with extended current capability (6A maximum collector current). While this part exceeds the 4A requirement and reduces maximum power rating to 2W, it maintains the 80V voltage rating and TO-220-3 package configuration. The TIP42BG is suitable for applications where higher current capacity is beneficial and power dissipation constraints are less stringent.

Parameter Comparison

Engineering Selection Recommendations

KSB596YTU Selection Criteria:

The KSB596YTU is the primary direct equivalent for D45C12G replacement. This part maintains identical electrical ratings across voltage (80V), current (4A), and power (30W) specifications. The KSB596YTU carries Last Time Buy status with 1669 units in stock, providing immediate availability. RoHS3 compliance and REACH unaffected status satisfy modern regulatory requirements. The reduced transition frequency (3MHz versus 40MHz) is acceptable for applications not requiring high-frequency switching performance. This part is suitable for direct pin-compatible substitution in existing designs.

TIP42BG Selection Criteria:

The TIP42BG serves as an alternative for applications requiring higher current capacity or where power dissipation is not a limiting factor. The 6A maximum collector current provides design margin above the 4A requirement. However, the reduced maximum power rating (2W versus 30W) restricts this part to lower-power applications. The TIP42BG is RoHS3 compliant with extended minimum operating temperature (-65°C). This part is suitable for redesigned circuits where thermal management and power budget have been re-evaluated.

Both substitute parts are manufactured by onsemi, ensuring consistent quality and documentation standards. Selection between KSB596YTU and TIP42BG depends on application-specific requirements for current capacity, power dissipation, and frequency response.

Frequently Asked Questions (FAQ)

Q: Can the KSB596YTU directly replace the D45C12G without circuit modification?

A: Yes. The KSB596YTU maintains identical voltage (80V), current (4A), and power (30W) ratings with TO-220-3 package compatibility. Pin configuration is identical. Direct substitution is supported for applications not dependent on the 40MHz transition frequency specification.

Q: What is the primary difference between KSB596YTU and TIP42BG?

A: The KSB596YTU matches the D45C12G current rating (4A) and power dissipation (30W) exactly. The TIP42BG provides higher current capacity (6A) but reduced power rating (2W). Selection depends on whether the application requires the full 30W power capability or benefits from higher current handling.

Q: Is the TIP42BG suitable for high-power applications?

A: No. The TIP42BG maximum power rating is 2W, significantly lower than the D45C12G specification of 30W. This part is restricted to low-power switching or signal applications. For applications requiring 30W dissipation, the KSB596YTU is the appropriate choice.

Q: Are there package compatibility concerns with these substitutes?

A: No. All three parts (D45C12G, KSB596YTU, TIP42BG) use TO-220-3 through-hole packaging with identical pin configuration. Physical mounting and thermal interface requirements are equivalent.

Q: What is the significance of the transition frequency difference?

A: The D45C12G specifies 40MHz transition frequency, while both substitutes specify 3MHz. This difference affects high-frequency switching performance. For applications operating below 3MHz, the substitutes perform identically. For applications requiring frequencies above 3MHz, the D45C12G characteristics cannot be fully replicated.

Q: Are regulatory compliance differences important for substitution?

A: The KSB596YTU and TIP42BG are both RoHS3 compliant, meeting current environmental standards. The D45C12G compliance status is not specified. For new designs or regulated applications, the RoHS3 compliant substitutes are preferred.

Q: What inventory considerations apply to these parts?

A: The D45C12G is obsolete with 630 units available. The KSB596YTU (Last Time Buy status) has 1669 units in stock. The TIP42BG (Last Time Buy status) has 2100 units available. For long-term production, the KSB596YTU or TIP42BG should be selected based on application requirements.