KSD1621UTF Equivalent & Substitute Parts

Part Overview

The KSD1621UTF is an NPN bipolar junction transistor manufactured by onsemi, rated for 25 V collector-emitter breakdown voltage and 2 A maximum collector current. This surface mount device in SOT-89-3 packaging is designed for general-purpose switching and amplification applications with a maximum power dissipation of 500 mW and transition frequency of 150 MHz. The KSD1621UTF is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Collector Current (Max)	2	A
Collector-Emitter Breakdown Voltage (Max)	25	V
Power Dissipation (Max)	500	mW
Transition Frequency	150	MHz
Operating Temperature (Max)	150	°C
Mounting Type	Surface Mount	—
Package / Case	TO-243AA	—
Moisture Sensitivity Level	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the KSD1621UTF is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Transistor Type: NPN configuration
Collector-Emitter Breakdown Voltage: 25 V minimum
Collector Current Rating: 2 A or greater
Package / Case: TO-243AA (surface mount compatibility)
Operating Temperature: 150°C maximum junction temperature
Mounting Type: Surface Mount

Secondary Compatibility Factors:

Transition Frequency: 150 MHz or greater
Power Dissipation: 500 mW or greater
Moisture Sensitivity Level: 1 (Unlimited)

The substitute parts identified—2SD2153T100U, 2SD2153T100V, 2SD2153T100W, and 2SD2537T100V—all meet or exceed the primary substitution criteria. These Rohm Semiconductor devices maintain the same TO-243AA package footprint and electrical ratings necessary for direct functional replacement in applications previously designed for the KSD1621UTF.

Parameter Comparison

Parameter	KSD1621UTF	2SD2153T100U	2SD2153T100V	2SD2153T100W	2SD2537T100V
Manufacturer	onsemi	Rohm Semiconductor	Rohm Semiconductor	Rohm Semiconductor	Rohm Semiconductor
Product Status	Obsolete	Active	Active	Active	Active
Transistor Type	NPN	NPN	NPN	NPN	NPN
Collector Current (Max)	2 A	2 A	2 A	2 A	1.2 A
Collector-Emitter Breakdown Voltage (Max)	25 V	25 V	25 V	25 V	25 V
Power Dissipation (Max)	500 mW	2 W	2 W	2 W	2 W
Transition Frequency	150 MHz	110 MHz	110 MHz	110 MHz	200 MHz
Operating Temperature (Max)	150°C	150°C	150°C	150°C	150°C
Package / Case	TO-243AA	TO-243AA	TO-243AA	TO-243AA	TO-243AA
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount
Moisture Sensitivity Level	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)
RoHS Status	—	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
REACH Status	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected

Engineering Selection Recommendations

For Direct Replacement (2SD2153 Series):

The 2SD2153T100U, 2SD2153T100V, and 2SD2153T100W are functionally equivalent to the KSD1621UTF for applications requiring 2 A collector current at 25 V. All three variants are manufactured by Rohm Semiconductor and maintain active product status with ROHS3 compliance and REACH unaffected certification. These devices provide superior power dissipation capability (2 W versus 500 mW) and are available in production quantities. Selection among the three 2SD2153 variants depends on DC current gain requirements: 2SD2153T100U provides 820 hFE minimum, 2SD2153T100V provides 820 hFE minimum, and 2SD2153T100W provides 1200 hFE minimum at specified test conditions.

For Current-Limited Applications (2SD2537T100V):

The 2SD2537T100V is suitable for applications where collector current does not exceed 1.2 A. This device offers higher transition frequency (200 MHz versus 150 MHz) and improved saturation voltage characteristics (300 mV versus 400 mV). The 2SD2537T100V is appropriate for designs with reduced current requirements and higher-frequency switching operations. All substitute parts maintain identical operating temperature ratings and moisture sensitivity levels as the original KSD1621UTF.

Frequently Asked Questions (FAQ)

Q: Can the 2SD2153 series directly replace the KSD1621UTF in all applications?

A: The 2SD2153T100U, 2SD2153T100V, and 2SD2153T100W maintain identical collector current (2 A), collector-emitter breakdown voltage (25 V), operating temperature (150°C), and TO-243AA package specifications as the KSD1621UTF. These devices are direct functional replacements for applications designed around the original part specifications.

Q: What is the difference between 2SD2153T100U, 2SD2153T100V, and 2SD2153T100W?

A: The primary difference among these three variants is the DC current gain (hFE) specification. The 2SD2153T100U and 2SD2153T100V both specify 820 hFE minimum at 500 mA collector current and 6 V collector-emitter voltage. The 2SD2153T100W specifies 1200 hFE minimum at the same test conditions. All other electrical and mechanical parameters are identical.

Q: When should the 2SD2537T100V be used instead of the 2SD2153 series?

A: The 2SD2537T100V is specified for applications where the maximum collector current requirement is 1.2 A or less. This device offers higher transition frequency (200 MHz) and lower saturation voltage (300 mV), making it suitable for higher-frequency switching circuits with reduced current demands.

Q: Are all substitute parts RoHS compliant?

A: Yes. The 2SD2153T100U, 2SD2153T100V, 2SD2153T100W, and 2SD2537T100V are all ROHS3 compliant. The original KSD1621UTF does not specify RoHS status, but all active substitute parts meet current RoHS3 requirements.

Q: Do the substitute parts have the same package footprint as the KSD1621UTF?

A: Yes. All substitute parts use the TO-243AA package / case designation with SOT-89-3 or MPT3 supplier device packaging. The physical footprint and pin configuration are compatible with designs originally specified for the KSD1621UTF in SOT-89-3 packaging.

Q: What is the moisture sensitivity level for the substitute parts?

A: All substitute parts maintain Moisture Sensitivity Level 1 (Unlimited), identical to the original KSD1621UTF. This classification indicates no moisture sensitivity precautions are required during storage or handling.

Q: Are the substitute parts available in production quantities?

A: Yes. The 2SD2153T100U, 2SD2153T100V, 2SD2153T100W, and 2SD2537T100V are all classified as active products with documented inventory availability, ranging from 1,464 to 30,300 pieces in stock.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message