KA556 Equivalent & Substitute Parts

Part Overview

The KA556 is a dual timer/oscillator IC manufactured by onsemi, utilizing 555-type circuitry in a 14-DIP through-hole package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The KA556 operates across a supply voltage range of 4.5V to 16V with a maximum supply current of 16 mA and supports operating temperatures from 0°C to 70°C.

Substiute Parts

KA556

onsemiIn Stock: 1472KA556 Datasheet

Current PartRFQ

NE556D

STMicroelectronicsIn Stock: 1904NE556D Datasheet

DirectRFQ

NA556N

Texas InstrumentsIn Stock: 1357NA556N Datasheet

UpgradeRFQ

SA556N

STMicroelectronicsIn Stock: 2927SA556N Datasheet

UpgradeRFQ

ICM7556IPDZ

Renesas Electronics CorporationIn Stock: 3634ICM7556IPDZ Datasheet

SimilarRFQ

NE556N

STMicroelectronicsIn Stock: 30933NE556N Datasheet

SimilarRFQ

TLC556CN

Texas InstrumentsIn Stock: 2151TLC556CN Datasheet

SimilarRFQ

TLC556IN

Texas InstrumentsIn Stock: 2159TLC556IN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KA556 is determined by the following critical parameters:

Package Compatibility: The 14-DIP through-hole package is the primary mechanical constraint. All direct substitutes must maintain this form factor to ensure PCB compatibility without redesign.

Electrical Compatibility: Supply voltage range (4.5V ~ 16V minimum overlap), supply current capability, and operating temperature range determine functional equivalence. Parts with wider voltage ranges or extended temperature specifications provide enhanced design flexibility.

Functional Type: All substitutes are 555-type dual timer/oscillator ICs, ensuring functional equivalence at the circuit level.

Substitution Categories:

• Direct Substitutes (Same Package): NE556N, SA556N, NA556N—maintain 14-DIP through-hole packaging with compatible electrical specifications.
• Similar Substitutes (Same Package, Enhanced Specs): ICM7556IPDZ, TLC556IN, TLC556CN—provide 14-DIP packaging with improved frequency performance, lower supply current, or extended temperature ranges.
• Package Variant (Surface Mount Alternative): NE556D—functionally equivalent but in 14-SOIC surface-mount package; requires PCB redesign.

Parameter Comparison

Engineering Selection Recommendations

For Direct Pin-Compatible Replacement (No PCB Redesign):

NA556N (Texas Instruments) is the preferred substitute. It maintains the 14-DIP through-hole package, supports the required 4.5V to 16V supply range, and is currently in active production status. The extended operating temperature range (-40°C to 105°C) provides design margin beyond the KA556 specification. RoHS3 compliance ensures regulatory alignment for new designs.

For Enhanced Performance with Same Package:

TLC556IN (Texas Instruments) offers the same 14-DIP through-hole package with significantly lower supply current (720 µA versus 16 mA), higher frequency capability (2.1MHz), and active product status. The extended temperature range (-40°C to 85°C) supports demanding applications. This part is suitable when power efficiency or higher frequency operation is required.

ICM7556IPDZ (Renesas Electronics Corporation) provides the widest supply voltage range (2V to 18V) and lowest supply current (120 µA), making it ideal for battery-powered or wide-input-voltage applications. Despite obsolete status, high inventory availability (3546 units) supports production needs.

For Surface-Mount Applications:

NE556D (STMicroelectronics) provides functional equivalence in 14-SOIC surface-mount packaging. This option requires PCB redesign but is suitable for new surface-mount assembly processes.

Product Status Considerations:

• Active status parts (NA556N, TLC556IN) are recommended for new designs requiring long-term supply assurance.
• Obsolete parts with high inventory (NE556N: 30,831 units; ICM7556IPDZ: 3,546 units) support legacy production continuity.
• Last Time Buy status (TLC556CN) indicates limited future availability; use only for existing designs with established supply agreements.

Frequently Asked Questions (FAQ)

Q: Can I use NE556D as a direct replacement for KA556?

A: NE556D is functionally equivalent but uses 14-SOIC surface-mount packaging instead of 14-DIP through-hole. Direct PCB substitution is not possible without redesign. Use NE556D only if your design supports surface-mount assembly.

Q: What is the key difference between NA556N and NE556N?

A: Both maintain 14-DIP through-hole packaging and 4.5V to 16V supply range. NA556N (Texas Instruments) is in active production with extended temperature range (-40°C to 105°C), while NE556N (STMicroelectronics) is obsolete with standard temperature range (0°C to 70°C). NA556N is preferred for new designs.

Q: Why does ICM7556IPDZ have lower supply current than KA556?

A: ICM7556IPDZ uses CMOS technology (120 µA typical) compared to the bipolar 555 design of KA556 (16 mA). The wider supply voltage range (2V to 18V) and lower current consumption make it suitable for battery-powered applications, though circuit behavior may differ slightly due to technology differences.

Q: Is TLC556IN compatible with the KA556 supply voltage range?

A: TLC556IN operates at 3V to 15V, which overlaps the KA556 range (4.5V to 16V) from 4.5V to 15V. At supply voltages below 4.5V or above 15V, TLC556IN is not suitable. Verify your application's actual supply voltage before substitution.

Q: Can I use these substitutes interchangeably in my existing design?

A: All listed substitutes are 555-type dual timer/oscillator ICs in 14-DIP through-hole packages (except NE556D). Pin compatibility is maintained. However, verify that your application's supply voltage, operating temperature, and frequency requirements fall within each substitute's specifications. Frequency differences and current consumption variations may affect circuit timing and power budget.

Q: What does "Last Time Buy" status mean for TLC556CN?

A: Last Time Buy indicates the manufacturer has announced end-of-life production. TLC556CN is available in limited quantities (2,125 units in stock) but will not be replenished. Use this part only for existing designs with established supply agreements; do not select for new designs.

Q: Are all these parts RoHS compliant?

A: All listed substitutes carry RoHS3 compliance status, ensuring compatibility with environmental regulations. The KA556 does not specify RoHS status but is REACH Unaffected, indicating no restricted substances of concern.