KA555I Equivalent & Substitute Parts

Part Overview

The KA555I is a 555 Type Timer/Oscillator (Single) IC manufactured by onsemi in 8-DIP packaging. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The KA555I operates across a supply voltage range of 4.5V to 16V with a maximum supply current of 7.5 mA and an operating temperature range of -40°C to 85°C. Direct substitutes and compatible alternatives are available from Texas Instruments, offering active product status and enhanced specifications in several cases.

Substiute Parts

KA555I

onsemiIn Stock: 1323KA555I Datasheet

Current PartRFQ

SA555P

Texas InstrumentsIn Stock: 47037SA555P Datasheet

DirectRFQ

NA555P

Texas InstrumentsIn Stock: 1619NA555P Datasheet

UpgradeRFQ

LM555CN/NOPB

Texas InstrumentsIn Stock: 2247LM555CN/NOPB Datasheet

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LMC555CN/NOPB

Texas InstrumentsIn Stock: 3101LMC555CN/NOPB Datasheet

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NE555P

Texas InstrumentsIn Stock: 156362NE555P Datasheet

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SE555P

Texas InstrumentsIn Stock: 8748SE555P Datasheet

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TLC555CP

Texas InstrumentsIn Stock: 20432TLC555CP Datasheet

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TLC555IP

Texas InstrumentsIn Stock: 18103TLC555IP Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the KA555I is determined by strict adherence to the following electrical and mechanical parameters:

Critical Compatibility Parameters:

• Package / Case: 8-DIP (0.300", 7.62mm) — all substitutes must match this form factor
• Mounting Type: Through Hole — all substitutes must support through-hole assembly
• Type: 555 Type, Timer/Oscillator (Single) — functional equivalence required
• Voltage - Supply: Minimum 4.5V support required for direct substitution
• Operating Temperature: Must support at least -40°C to 85°C range for full compatibility

Substitution Categories:

Direct Manufacturer Substitute (Active Status):

• SA555P: Meets all critical parameters with 100kHz frequency specification and active product status

Upgrade Substitute (Extended Temperature Range):

• NA555P: Meets all critical parameters with extended operating temperature to 105°C and active product status

Compatible Alternatives (Active Status, Parameter Variations):

• LM555CN/NOPB: Meets package and voltage requirements; operating temperature limited to 0°C ~ 70°C
• NE555P: Meets package and voltage requirements; operating temperature limited to 0°C ~ 70°C
• SE555P: Meets package requirements; extended voltage range to 18V and extended temperature range to -55°C ~ 125°C
• TLC555CP: Meets package requirements; reduced voltage range (2V ~ 15V) and operating temperature limited to 0°C ~ 70°C
• TLC555IP: Meets package requirements; reduced voltage range (3V ~ 15V) with extended temperature range to -40°C ~ 85°C

Enhanced Performance Alternative (Active Status, Higher Frequency):

• LMC555CN/NOPB: Meets package and temperature requirements; reduced voltage range (1.5V ~ 15V) with 3MHz frequency capability

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement with Active Product Status: SA555P is the primary direct substitute, maintaining identical voltage supply range (4.5V ~ 16V) and operating temperature range (-40°C ~ 85°C) as the KA555I. This part carries active product status and ROHS3 compliance.

For Extended Temperature Operation: NA555P extends the upper operating temperature limit to 105°C while maintaining the same voltage supply range and lower temperature limit as the KA555I. This part is suitable for applications requiring enhanced thermal performance and carries active product status with ROHS3 compliance.

For Full Temperature Range with Extended Voltage Capability: SE555P provides the widest operating temperature range (-55°C ~ 125°C) and extended voltage supply range (4.5V ~ 18V). This part is appropriate for demanding environmental applications and carries active product status with ROHS3 compliance.

For Low-Power Applications: LMC555CN/NOPB and TLC555IP offer significantly reduced supply current (150 µA and 360 µA respectively) compared to the KA555I (7.5 mA). TLC555IP maintains the full temperature range (-40°C ~ 85°C) and is suitable for battery-powered or low-power designs. Both carry active product status with ROHS3 compliance.

For High-Frequency Applications: LMC555CN/NOPB (3MHz) and TLC555CP/TLC555IP (2.1MHz) provide higher frequency operation than standard 555 timers. LMC555CN/NOPB maintains the full temperature range and is suitable for timing applications requiring higher frequency capability.

Compliance Considerations: All Texas Instruments substitutes carry ROHS3 compliance and REACH Unaffected status, matching the regulatory profile of the KA555I. All parts maintain EAR99 ECCN classification and 8542.39.0001 HTSUS code.

Frequently Asked Questions (FAQ)

Q: Can SA555P directly replace KA555I in all applications? A: SA555P is a direct substitute for KA555I, matching the critical parameters of 8-DIP package, 4.5V ~ 16V supply voltage, and -40°C ~ 85°C operating temperature range. The primary difference is active product status and ROHS3 compliance. Verify application-specific frequency requirements before substitution.

Q: What is the difference between NA555P and SA555P? A: NA555P extends the upper operating temperature limit to 105°C compared to SA555P's 85°C maximum. Both maintain identical voltage supply range (4.5V ~ 16V) and 8-DIP package. Select NA555P for applications requiring operation above 85°C.

Q: Are LM555CN/NOPB and NE555P interchangeable with KA555I? A: Both parts match the 8-DIP package and 4.5V ~ 16V voltage supply range. However, both are limited to 0°C ~ 70°C operating temperature, which does not cover the full -40°C ~ 85°C range of the KA555I. Use these parts only in applications operating within 0°C ~ 70°C.

Q: Why would I choose TLC555IP over SA555P? A: TLC555IP offers significantly lower supply current (360 µA versus 10 mA) and higher frequency capability (2.1MHz versus 100kHz). Select TLC555IP for low-power applications or designs requiring higher frequency operation. TLC555IP maintains the full -40°C ~ 85°C temperature range but has a reduced voltage supply range (3V ~ 15V).

Q: Is SE555P suitable for extreme temperature environments? A: SE555P provides the widest operating temperature range (-55°C ~ 125°C) and extended voltage supply range (4.5V ~ 18V) among all substitutes. This part is appropriate for military, aerospace, or industrial applications requiring operation in extreme temperature conditions.

Q: What is the package compatibility for all these substitutes? A: All substitute parts use 8-DIP (0.300", 7.62mm) through-hole packaging, ensuring direct mechanical compatibility with KA555I footprints. No PCB layout modifications are required for package substitution.

Q: Do all substitutes have the same supply current requirements? A: No. Standard 555 variants (SA555P, NA555P, LM555CN/NOPB, NE555P, SE555P) draw 10 mA. Low-power variants (LMC555CN/NOPB, TLC555CP, TLC555IP) draw 150 µA to 360 µA. Verify power supply capacity when substituting with low-power variants.

Q: Are there RoHS compliance differences between substitutes? A: All Texas Instruments substitutes carry ROHS3 compliance. The KA555I carries no RoHS designation. All parts maintain REACH Unaffected status and EAR99 ECCN classification.