ZTX649STOB Equivalent & Substitute Parts

Part Overview

The ZTX649STOB is a Bipolar (BJT) NPN transistor manufactured by Diodes Incorporated, designed for general-purpose switching and amplification applications. This component operates at a maximum collector current of 2 A with a collector-emitter breakdown voltage of 25 V and delivers 1 W maximum power dissipation. The device features a transition frequency of 240 MHz and is housed in an E-Line (TO-92 compatible) through-hole package with formed leads.

The ZTX649STOB carries an Obsolete product status. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure component availability for production, and support long-term system maintenance and repair operations.

Substiute Parts

ZTX649STOB

Diodes IncorporatedIn Stock: 1031ZTX649STOB Datasheet

Current PartRFQ

ZTX649STZ

Diodes IncorporatedIn Stock: 2047ZTX649STZ Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ZTX649STOB is determined by electrical and mechanical parameter equivalence within the NPN Bipolar (BJT) transistor category. The critical parameters that establish substitution eligibility are:

Electrical Parameters:

• Transistor Type: NPN
• Maximum Collector Current (Ic): 2 A
• Maximum Collector-Emitter Breakdown Voltage (Vce): 25 V
• Saturation Voltage (Vce Sat): 500mV @ 200mA, 2A
• Collector Cutoff Current (ICBO): 100nA
• DC Current Gain (hFE): 100 @ 1A, 2V
• Maximum Power Dissipation: 1 W
• Transition Frequency: 240MHz
• Operating Temperature Range: -55°C ~ 200°C

Mechanical Parameters:

• Mounting Type: Through Hole
• Package Type: E-Line-3, Formed Leads (TO-92 compatible)

Compliance Parameters:

• RoHS3 Compliance
• REACH Unaffected Status
• Moisture Sensitivity Level 1

Substitute parts must match all electrical specifications, maintain identical package geometry and lead configuration, and satisfy the same regulatory compliance requirements.

Parameter Comparison

Engineering Selection Recommendations

The ZTX649STZ serves as a direct electrical and mechanical equivalent to the ZTX649STOB. Both components are manufactured by Diodes Incorporated and share identical electrical specifications across all critical parameters: collector current, breakdown voltage, saturation voltage, current gain, power rating, and transition frequency. The operating temperature range and package geometry are identical.

The primary distinction between these parts is product status and packaging format. The ZTX649STOB is classified as Obsolete, while the ZTX649STZ maintains Active product status. The ZTX649STZ is supplied in Cut Tape (CT) packaging, whereas the ZTX649STOB was supplied in tube packaging. Both components satisfy ROHS3 compliance and REACH requirements with identical moisture sensitivity classification.

For new designs and ongoing production requiring NPN BJT transistors with 2 A collector current and 25 V breakdown voltage specifications, the ZTX649STZ is the appropriate selection due to its active product status and continued manufacturer support. For legacy system repairs or maintenance requiring direct form-fit-function replacement of existing ZTX649STOB components, the ZTX649STZ provides complete electrical and mechanical compatibility.

Frequently Asked Questions (FAQ)

Q: Can the ZTX649STZ directly replace the ZTX649STOB in existing circuit designs?

A: Yes. The ZTX649STZ is electrically and mechanically equivalent to the ZTX649STOB. All electrical parameters, including collector current, breakdown voltage, saturation voltage, current gain, power dissipation, and transition frequency are identical. Both components use the same E-Line (TO-92 compatible) through-hole package with formed leads, enabling direct pin-compatible substitution without circuit modification.

Q: What is the significance of the different packaging formats (STOB vs. STZ)?

A: The STOB designation indicates tube packaging, while STZ indicates Cut Tape (CT) packaging. These are distribution and handling formats only and do not affect component electrical performance or physical dimensions. The actual component and lead configuration remain identical. Selection between packaging formats depends on procurement requirements and assembly process compatibility.

Q: Are there compliance or regulatory differences between these parts?

A: No. Both the ZTX649STOB and ZTX649STZ maintain identical compliance status: ROHS3 Compliant, REACH Unaffected, and Moisture Sensitivity Level 1 (Unlimited). Both components satisfy the same regulatory and environmental requirements.

Q: Why is the ZTX649STOB listed as Obsolete?

A: The ZTX649STOB has reached end-of-life status with the manufacturer. The ZTX649STZ remains in active production and is the current equivalent offering. For applications requiring this transistor specification, the ZTX649STZ should be specified for new designs and future procurement.

Q: Are there any thermal or performance differences between these transistors?

A: No. Both components operate across the identical temperature range of -55°C to 200°C (junction temperature) and deliver the same maximum power dissipation of 1 W. Thermal characteristics and performance parameters are equivalent.

Q: Can the ZTX649STZ be used in high-frequency applications?

A: Yes. The ZTX649STZ operates at a transition frequency of 240MHz, supporting high-frequency switching and amplification applications within the specified electrical operating parameters.