ZTL431BCSTZ Equivalent & Substitute Parts

Part Overview

The ZTL431BCSTZ is a shunt voltage reference IC manufactured by Diodes Incorporated, designed for adjustable voltage regulation applications. This device provides a fixed 2.5V output with adjustable capability up to 20V, delivering 100 mA output current with ±0.5% tolerance. The component is packaged in TO-92 through-hole configuration and is currently classified as obsolete. Due to its obsolete status, identifying functionally equivalent active alternatives is essential for design continuity and procurement reliability.

Substiute Parts

ZTL431BCSTZ

Diodes IncorporatedIn Stock: 870ZTL431BCSTZ Datasheet

Current PartRFQ

ZTL431BFTA

Diodes IncorporatedIn Stock: 20402ZTL431BFTA Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ZTL431BCSTZ is determined by electrical parameter equivalence across the following criteria:

Electrical Equivalence Requirements:

• Reference Type: Shunt (identical functional topology)
• Output Type: Adjustable (maintains voltage regulation capability)
• Voltage - Output (Min/Fixed): 2.5V (identical minimum output)
• Voltage - Output (Max): 20V (identical maximum output range)
• Current - Output: 100 mA (identical output current rating)
• Tolerance: ±0.5% (identical accuracy specification)
• Current - Cathode: 600 µA (identical cathode current)
• Operating Temperature: -40°C ~ 125°C (identical thermal range)

Compliance Equivalence:

• RoHS3 Compliant status maintained
• Base Product Number: ZTL431 (same device family)

The ZTL431BFTA meets all electrical and compliance requirements for direct substitution. The primary difference is packaging format: the substitute transitions from through-hole TO-92 to surface-mount SOT-23-3, requiring PCB layout modification but maintaining full electrical compatibility.

Parameter Comparison

Engineering Selection Recommendations

The ZTL431BFTA is the direct electrical equivalent for the obsolete ZTL431BCSTZ. Both devices share identical electrical specifications within the shunt voltage reference category and maintain equivalent compliance certifications (ROHS3, REACH Unaffected, EAR99 classification).

Selection between these parts depends on PCB design constraints:

ZTL431BCSTZ (Through-Hole TO-92): Suitable for existing through-hole PCB designs. Obsolete status limits procurement to existing inventory.

ZTL431BFTA (Surface-Mount SOT-23-3): Recommended for new designs and redesigns. Active product status ensures long-term availability. Surface-mount packaging enables higher-density PCB layouts and automated assembly processes.

Both parts are manufactured by Diodes Incorporated and carry identical electrical performance ratings. The choice between them is determined by PCB assembly technology and design architecture rather than functional capability.

Frequently Asked Questions (FAQ)

Q: Can ZTL431BFTA directly replace ZTL431BCSTZ in existing designs?

A: Electrically, yes. The ZTL431BFTA provides identical voltage reference performance, output current, tolerance, and operating temperature range. However, the package change from TO-92 through-hole to SOT-23-3 surface-mount requires PCB layout modification. Pin-to-pin electrical functionality is equivalent.

Q: What are the key differences between these parts?

A: The primary difference is packaging format and mounting technology. ZTL431BCSTZ uses through-hole TO-92-3 packaging; ZTL431BFTA uses surface-mount SOT-23-3 packaging. All electrical parameters, including voltage range (2.5V to 20V), output current (100 mA), and tolerance (±0.5%), are identical.

Q: Why is ZTL431BCSTZ classified as obsolete?

A: The ZTL431BCSTZ is obsolete due to market transition toward surface-mount technology. The ZTL431BFTA represents the active continuation of this product line in modern packaging.

Q: Are there compliance differences between these parts?

A: No. Both parts maintain ROHS3 compliance, REACH Unaffected status, and identical EAR99 ECCN classification. Moisture sensitivity level (MSL 1 - Unlimited) is equivalent.

Q: What is the cathode current specification, and why does it matter?

A: Both parts specify 600 µA cathode current. This parameter defines the minimum operating current required to maintain voltage regulation accuracy. Circuit design must ensure this minimum current is supplied for proper reference operation.

Q: Can I use ZTL431BFTA in a through-hole socket designed for ZTL431BCSTZ?

A: No. The SOT-23-3 package is physically incompatible with TO-92 through-hole sockets. PCB redesign is required to accommodate surface-mount soldering.