KA7918TU Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The KA7918TU is a linear voltage regulator IC manufactured by onsemi, designed to provide a fixed negative output of -18V at 1A in a TO-220-3 package. This device is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing system support and component procurement.

The KA7918TU serves applications requiring stable negative voltage regulation with integrated over-temperature and short-circuit protection. Due to its obsolete status, sourcing direct replacements from active product lines ensures long-term availability and supply chain continuity.

Substiute Parts

KA7918TU

onsemiIn Stock: 2262KA7918TU Datasheet

Current PartRFQ

MC7918CTG

onsemiIn Stock: 2043MC7918CTG Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the KA7918TU are identified based on the following critical parameters that determine functional equivalence:

• Output Configuration: Negative voltage regulation
• Output Voltage: Fixed -18V
• Maximum Output Current: 1A minimum
• Maximum Input Voltage: -35V or greater
• Package Type: TO-220-3 through-hole mounting
• Operating Temperature Range: 0°C ~ 125°C

The MC7918CTG meets all substitution criteria, maintaining identical output voltage, current rating, input voltage specification, package configuration, and operating temperature range. Both devices are manufactured by onsemi and share the same functional architecture for negative linear voltage regulation.

Parameter Comparison

Engineering Selection Recommendations

The MC7918CTG is the direct substitute for the KA7918TU based on electrical and mechanical equivalence. The MC7918CTG offers the following advantages:

• Active Product Status: The MC7918CTG is an active product line component, ensuring continued availability and supply chain support compared to the obsolete KA7918TU.
• Improved Dropout Voltage: The MC7918CTG exhibits lower typical dropout voltage (1.3V vs. 2V), resulting in improved efficiency in applications with limited input voltage headroom.
• Enhanced Protection: The MC7918CTG includes over-current protection in addition to over-temperature protection, providing additional circuit safeguarding.
• Regulatory Compliance: The MC7918CTG is ROHS3 compliant, meeting current environmental and regulatory requirements for new designs and procurement.

Both devices maintain identical output voltage, current rating, input voltage specification, and thermal operating range, ensuring direct functional compatibility in existing circuit designs.

Frequently Asked Questions (FAQ)

Q: Can the MC7918CTG be used as a direct replacement for the KA7918TU without circuit modifications?

A: Yes. Both devices share identical output voltage (-18V), output current (1A), maximum input voltage (-35V), operating temperature range (0°C ~ 125°C), and TO-220-3 package configuration. No circuit modifications are required for substitution.

Q: What is the difference in dropout voltage between these parts?

A: The KA7918TU has a maximum typical dropout voltage of 2V @ 1A, while the MC7918CTG has 1.3V @ 1A. This difference may be beneficial in applications where input voltage margin is limited, as the MC7918CTG requires less input-to-output voltage differential to maintain regulation.

Q: Are the pinouts identical between KA7918TU and MC7918CTG?

A: Yes. Both devices use the TO-220-3 package with identical pin configuration, allowing direct socket substitution.

Q: Why is the KA7918TU listed as obsolete?

A: The KA7918TU has reached end-of-life status in the manufacturer's product portfolio. The MC7918CTG represents the active equivalent in onsemi's current product line for -18V, 1A negative linear voltage regulation.

Q: Does the MC7918CTG meet current environmental standards?

A: Yes. The MC7918CTG is ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for component procurement and new product designs.

Q: What is the difference in protection features?

A: The KA7918TU provides over-temperature and short-circuit protection. The MC7918CTG provides over-current and over-temperature protection. Both offer thermal safeguarding; the MC7918CTG adds over-current detection for enhanced circuit protection.