HT18G A1G Equivalent & Substitute Parts

Part Overview

The HT18G A1G is a general-purpose rectifier diode manufactured by Taiwan Semiconductor Corporation, rated for 1000 V DC reverse voltage and 1 A average rectified current in a through-hole TS-1 axial package. This component is classified as a fast recovery diode with a reverse recovery time of 75 ns, suitable for standard rectification applications requiring high voltage and moderate current handling.

The HT18G A1G has been discontinued at DiGi Electronics. Identifying equivalent substitute parts ensures design continuity and maintains supply chain reliability for applications currently utilizing this component.

Substiute Parts

HT18G A1G

Taiwan Semiconductor CorporationIn Stock: 918HT18G A1G Datasheet

Current PartRFQ

HT18G A0G

Taiwan Semiconductor CorporationIn Stock: 901HT18G A0G Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the HT18G A1G is determined by electrical and mechanical parameter equivalence. The following criteria establish valid substitutes:

Electrical Parameters (Must Match):

• Voltage - DC Reverse (Vr) (Max): 1000 V
• Current - Average Rectified (Io): 1 A
• Voltage - Forward (Vf) (Max) @ If: 1.7 V @ 1 A
• Reverse Recovery Time (trr): 75 ns
• Current - Reverse Leakage @ Vr: 5 µA @ 1000 V
• Capacitance @ Vr, F: 10 pF @ 4V, 1MHz
• Technology: Standard
• Speed Classification: Fast Recovery ≤ 500ns, > 200mA (Io)

Mechanical Parameters (Must Match):

• Mounting Type: Through Hole
• Package / Case: T-18, Axial
• Operating Temperature - Junction: -55°C to 150°C

Compliance & Status (Preferred):

• RoHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)
• REACH Status: REACH Unaffected
• Active product status preferred for long-term availability

Parameter Comparison

Engineering Selection Recommendations

The HT18G A0G is a direct electrical and mechanical equivalent to the HT18G A1G. All specified electrical parameters, including reverse voltage rating, forward voltage drop, reverse recovery time, and leakage current, are identical. Both components share the same T-18 axial through-hole package and identical operating temperature range.

The primary distinction is product status: the HT18G A1G is discontinued at DiGi Electronics, while the HT18G A0G maintains active status. Both components carry identical compliance certifications: ROHS3 Compliant, REACH Unaffected, and Moisture Sensitivity Level 1 (Unlimited).

For applications currently specified with HT18G A1G, the HT18G A0G provides full functional and physical compatibility with no design modifications required. The active product status of the HT18G A0G ensures continued availability and supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can the HT18G A0G be used as a direct replacement for the HT18G A1G?

A: Yes. The HT18G A0G is electrically and mechanically identical to the HT18G A1G. All electrical parameters, including voltage ratings, current capacity, forward voltage drop, and reverse recovery time, are equivalent. The T-18 axial through-hole package is identical, requiring no PCB layout modifications.

Q: What is the difference between the HT18G A1G and HT18G A0G?

A: The components are electrically and mechanically identical. The difference is in the product status designation: HT18G A1G is discontinued at DiGi Electronics, while HT18G A0G is active. The alphanumeric suffix (A1G vs. A0G) indicates a manufacturing or distribution variant from Taiwan Semiconductor Corporation.

Q: Are both parts RoHS compliant?

A: Yes. Both the HT18G A1G and HT18G A0G are ROHS3 Compliant and REACH Unaffected. Both carry Moisture Sensitivity Level 1 (Unlimited), indicating no moisture sensitivity restrictions.

Q: What is the reverse recovery time specification, and why is it important?

A: Both parts specify a reverse recovery time (trr) of 75 ns, classifying them as fast recovery diodes. This parameter defines the time required for the diode to transition from forward conduction to reverse blocking when the applied voltage reverses. Fast recovery characteristics are essential in switching applications and high-frequency rectification circuits.

Q: Can these diodes be used in high-temperature applications?

A: Both components are rated for junction operating temperatures from -55°C to 150°C. Applications requiring operation at the upper temperature limit must account for the temperature coefficient of forward voltage drop and reverse leakage current, which increase with temperature.

Q: What is the significance of the 1 A average rectified current rating?

A: The 1 A rating specifies the maximum average DC current the diode can conduct during rectification. This is distinct from peak current capability. Circuit design must ensure that average current does not exceed this specification under normal operating conditions.

Q: Are there any package considerations for PCB assembly?

A: Both components use the T-18 axial through-hole package. This package style requires through-hole mounting on PCBs and is not compatible with surface-mount assembly processes. Lead spacing and hole diameter specifications must be verified against PCB design files.