KA555ID Equivalent & Substitute Parts

Part Overview

The KA555ID is a 555 Type Timer/Oscillator (Single) IC manufactured by onsemi in 8-SOIC surface mount packaging. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The KA555ID operates across a supply voltage range of 4.5V to 16V with a maximum supply current of 7.5 mA and supports operating temperatures from -40°C to 85°C. Identifying compatible substitutes ensures design flexibility and supply chain resilience.

Key Parameters

Parameter	KA555ID Specification
Manufacturer	onsemi
Part Number	KA555ID
Type	555 Type, Timer/Oscillator (Single)
Package / Case	8-SOIC (0.154", 3.90mm Width)
Mounting Type	Surface Mount
Voltage - Supply	4.5V ~ 16V
Current - Supply	7.5 mA
Operating Temperature	-40°C ~ 85°C
Product Status	Obsolete
Moisture Sensitivity Level (MSL)	1 (Unlimited)
REACH Status	REACH Unaffected

Substitute Part Grouping Explanation

Substitution of the KA555ID is determined by strict alignment of the following critical parameters:

Package / Case: 8-SOIC (0.154", 3.90mm Width) — mechanical and electrical compatibility
Type: 555 Type, Timer/Oscillator (Single) — functional equivalence
Voltage - Supply: 4.5V ~ 16V — operational voltage compatibility
Mounting Type: Surface Mount — assembly process compatibility
Operating Temperature Range: -40°C ~ 85°C or wider — thermal envelope compatibility

Substitute parts are grouped into three categories based on their relationship to the main part:

Direct Substitutes: Parts with identical or superior electrical and thermal specifications
Similar Substitutes: Parts meeting core functional and package requirements with minor parameter variations
Upgrade Substitutes: Active production parts with enhanced specifications or better availability

Parameter Comparison

Part Number	Manufacturer	Package	Voltage - Supply	Current - Supply	Operating Temperature	Product Status	Frequency
KA555ID	onsemi	8-SOIC	4.5V ~ 16V	7.5 mA	-40°C ~ 85°C	Obsolete	—
MC1455BDR2G	onsemi	8-SOIC	4.5V ~ 16V	10 mA	-40°C ~ 85°C	Active	—
MC1455DR2G	onsemi	8-SOIC	4.5V ~ 16V	10 mA	0°C ~ 70°C	Active	—
SA555D	Fairchild Semiconductor	8-SOIC	4.5V ~ 16V	10 mA	-40°C ~ 105°C	Obsolete	500kHz
NA555D	Texas Instruments	8-SOIC	4.5V ~ 16V	10 mA	-40°C ~ 105°C	Last Time Buy	100kHz
NA555DR	Texas Instruments	8-SOIC	4.5V ~ 16V	10 mA	-40°C ~ 105°C	Active	100kHz
NA555S-13	Diodes Incorporated	8-SOIC	4.5V ~ 16V	13 mA	-40°C ~ 105°C	Active	500kHz
LM555CM/NOPB	Texas Instruments	8-SOIC	4.5V ~ 16V	10 mA	0°C ~ 70°C	Active	100kHz
LM555CMX/NOPB	Texas Instruments	8-SOIC	4.5V ~ 16V	10 mA	0°C ~ 70°C	Active	100kHz
LMC555CM/NOPB	Texas Instruments	8-SOIC	1.5V ~ 15V	150 µA	-40°C ~ 85°C	Last Time Buy	3MHz
LMC555CMX/NOPB	Texas Instruments	8-SOIC	1.5V ~ 15V	150 µA	-40°C ~ 85°C	Active	3MHz

Engineering Selection Recommendations

Primary Recommendation: NA555DR

The NA555DR (Texas Instruments) is the preferred substitute for the KA555ID. It maintains identical package geometry (8-SOIC), voltage supply range (4.5V ~ 16V), and operating temperature range (-40°C ~ 105°C, which exceeds the KA555ID specification). The NA555DR is in active production status with high inventory availability (43,850 pcs), ensuring long-term supply continuity. It carries ROHS3 compliance and REACH Unaffected status, meeting modern regulatory requirements.

Secondary Recommendation: MC1455BDR2G

The MC1455BDR2G (onsemi) provides continuity with the original manufacturer while offering active product status. It matches the KA555ID in package, voltage range, and operating temperature (-40°C ~ 85°C). Supply current is 10 mA versus 7.5 mA for the KA555ID, which is acceptable for most applications within the same voltage and thermal envelope. Inventory availability is strong (3,266 pcs).

Alternative for Extended Temperature Range: SA555D

The SA555D (Fairchild Semiconductor) extends the operating temperature range to -40°C ~ 105°C, providing thermal margin beyond the KA555ID specification. However, it is classified as obsolete, limiting its suitability for new designs requiring long-term supply assurance.

Low-Power Alternative: LMC555CMX/NOPB

The LMC555CMX/NOPB (Texas Instruments) is suitable only for applications where the reduced supply voltage range (1.5V ~ 15V) and significantly lower supply current (150 µA) are compatible with system requirements. This part is in active production with excellent inventory (31,756 pcs) and operates at -40°C ~ 85°C, matching the KA555ID thermal specification.

Temperature-Restricted Alternatives: LM555CM/NOPB and LM555CMX/NOPB

These Texas Instruments parts operate within a narrower temperature range (0°C ~ 70°C) compared to the KA555ID (-40°C ~ 85°C). Selection is appropriate only for applications with restricted operating temperature requirements. Both are in active production with adequate inventory.

Frequently Asked Questions (FAQ)

Q: Can I directly replace KA555ID with NA555DR without circuit modifications?

A: Yes. The NA555DR maintains the same 8-SOIC package footprint, identical voltage supply range (4.5V ~ 16V), and compatible operating temperature range (-40°C ~ 105°C, which exceeds KA555ID). Pin configuration and functional behavior are equivalent for standard 555 timer applications.

Q: What is the significance of the supply current difference between KA555ID (7.5 mA) and substitute parts (10 mA)?

A: The higher supply current in most substitutes (10 mA versus 7.5 mA) represents a worst-case specification. This difference is typically negligible in circuit design unless power budget constraints are extremely tight. Verify power supply capacity in your specific application.

Q: Why do some substitutes have different operating temperature ranges?

A: Operating temperature range reflects the manufacturer's tested and validated thermal envelope. The KA555ID operates from -40°C to 85°C. Substitutes like NA555DR extend this to 105°C, providing additional thermal margin. Conversely, LM555CM/NOPB is limited to 0°C ~ 70°C and is suitable only for commercial temperature applications. Select based on your system's thermal requirements.

Q: Are all substitute parts RoHS3 compliant?

A: All listed substitute parts carry RoHS3 compliance status. The KA555ID does not specify RoHS status in the provided data. If RoHS compliance is a design requirement, all substitutes meet this criterion.

Q: What is the difference between MC1455BDR2G and MC1455DR2G?

A: Both are onsemi MC1455 variants in 8-SOIC packaging. MC1455BDR2G operates across -40°C ~ 85°C (matching KA555ID), while MC1455DR2G is restricted to 0°C ~ 70°C. Select MC1455BDR2G for applications requiring the full temperature range.

Q: Can I use LMC555CMX/NOPB as a direct replacement?

A: LMC555CMX/NOPB is functionally equivalent but operates at a reduced supply voltage range (1.5V ~ 15V versus 4.5V ~ 16V) and significantly lower supply current (150 µA). Use this part only if your circuit operates within the 1.5V ~ 15V range and benefits from ultra-low power consumption. It is not a general-purpose direct replacement.

Q: What packaging formats are available for substitute parts?

A: All substitute parts are available in 8-SOIC surface mount package. Packaging options vary by part number: some are supplied in Cut Tape (CT) & Digi-Reel format, others in Tube or Tape & Reel (TR). Verify packaging compatibility with your procurement and assembly processes.

Q: Is inventory availability a factor in selecting a substitute?

A: Yes. NA555DR offers the highest inventory (43,850 pcs), ensuring supply continuity. LMC555CMX/NOPB (31,756 pcs) and MC1455DR2G (25,300 pcs) also provide strong availability. Parts marked "Last Time Buy" (NA555D, LMC555CM/NOPB) have limited remaining stock and are not recommended for new designs.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message