BC373RL1 Equivalent & Substitute Parts

Part Overview

The BC373RL1 is a Bipolar (BJT) Transistor NPN - Darlington configuration manufactured by onsemi, rated for 80 V collector-emitter breakdown voltage and 1 A maximum collector current. The device is packaged in TO-92 (TO-226-3) through-hole format with a maximum power dissipation of 625 mW and transition frequency of 200 MHz. The BC373RL1 is classified as obsolete product status. Identification of equivalent substitute parts is necessary due to obsolescence and potential supply discontinuation, requiring selection of active alternative components that maintain electrical and mechanical compatibility within specified parameter ranges.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN - Darlington	—
Current - Collector (Ic) (Max)	1	A
Voltage - Collector Emitter Breakdown (Max)	80	V
Power - Max	625	mW
Frequency - Transition	200	MHz
Mounting Type	Through Hole	—
Package / Case	TO-92-3	—
Operating Temperature Range	-55 to 150	°C

Substitute Part Grouping Explanation

Substitution of the BC373RL1 is determined by equivalence across the following critical electrical and mechanical parameters:

Electrical Equivalence Criteria:

Transistor Type: NPN - Darlington configuration
Maximum Collector Current (Ic): 1 A or greater
Maximum Collector-Emitter Breakdown Voltage (Vce): 80 V or greater
Mounting Type: Through Hole
Package Compatibility: TO-92 or TO-92 compatible form factor

Mechanical Compatibility:

Lead configuration: Three-lead through-hole package with formed leads
Physical footprint: Compatible with TO-92 standard PCB hole spacing

The ZTX603STZ manufactured by Diodes Incorporated satisfies all substitution criteria. This device maintains identical maximum ratings for collector current (1 A) and collector-emitter breakdown voltage (80 V), operates within compatible temperature ranges, and utilizes a through-hole E-Line package format that is mechanistically compatible with TO-92 footprints.

Parameter Comparison

Parameter	BC373RL1 (onsemi)	ZTX603STZ (Diodes Inc.)	Unit
Transistor Type	NPN - Darlington	NPN - Darlington	—
Current - Collector (Ic) (Max)	1	1	A
Voltage - Collector Emitter Breakdown (Max)	80	80	V
Vce Saturation (Max)	1.1 @ 250µA, 250mA	1 @ 1mA, 1A	V
Current - Collector Cutoff (Max)	100nA	10µA	A
DC Current Gain (hFE) (Min)	10000 @ 100mA, 5V	2000 @ 1A, 5V	—
Power - Max	625	1	mW
Frequency - Transition	200	150	MHz
Operating Temperature Range	-55 to 150	-55 to 200	°C
Mounting Type	Through Hole	Through Hole	—
Package / Case	TO-92-3	E-Line-3	—
Product Status	Obsolete	Active	—
RoHS Status	Non-compliant	ROHS3 Compliant	—

Engineering Selection Recommendations

BC373RL1 (onsemi): This component is classified as obsolete product status. RoHS non-compliance indicates this device does not meet current environmental and material restriction standards. Selection of this part is limited to legacy system maintenance or applications where existing inventory is available.

ZTX603STZ (Diodes Incorporated): This component is classified as active product status with ROHS3 compliance certification. The ZTX603STZ is suitable for new designs and ongoing production applications. The device provides superior power dissipation capability (1 W versus 625 mW), extended maximum operating temperature (200°C versus 150°C), and meets current regulatory compliance requirements. The E-Line package format is mechanistically compatible with TO-92 footprints for through-hole PCB assembly.

Selection of ZTX603STZ is appropriate for applications requiring component substitution due to BC373RL1 obsolescence, new product development, or compliance with RoHS3 standards.

Frequently Asked Questions (FAQ)

Q: Can the ZTX603STZ directly replace the BC373RL1 in existing PCB designs?

A: The ZTX603STZ utilizes an E-Line package format that is mechanistically compatible with TO-92 through-hole footprints. Physical lead spacing and hole positioning are compatible with standard TO-92 PCB layouts. Electrical parameters (1 A maximum collector current, 80 V maximum collector-emitter breakdown voltage) are equivalent. Direct substitution is supported from a mechanical and electrical standpoint.

Q: What are the differences in electrical performance between these devices?

A: The ZTX603STZ provides higher power dissipation (1 W versus 625 mW), lower transition frequency (150 MHz versus 200 MHz), and lower DC current gain at rated conditions (2000 versus 10000). The ZTX603STZ exhibits higher collector cutoff current (10µA versus 100nA). These differences are within acceptable ranges for most Darlington transistor applications but should be verified against specific circuit requirements.

Q: Is the ZTX603STZ suitable for high-temperature applications?

A: The ZTX603STZ supports maximum operating junction temperature of 200°C, compared to 150°C for the BC373RL1. This extended temperature range provides additional thermal margin for applications operating in elevated ambient conditions.

Q: What compliance certifications apply to each device?

A: The BC373RL1 is RoHS non-compliant. The ZTX603STZ is ROHS3 compliant. Both devices are REACH unaffected and classified under ECCN EAR99. Selection of ZTX603STZ is required for applications subject to RoHS3 regulatory requirements.

Q: Are there inventory considerations for component selection?

A: The BC373RL1 is classified as obsolete with 682 pieces in current stock. The ZTX603STZ is classified as active product with 843 pieces in current stock. Long-term availability and supply continuity favor selection of the ZTX603STZ for ongoing production requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message