SA556NG4 Equivalent & Substitute Parts

Part Overview

The SA556NG4 is a dual timer/oscillator IC based on the 555 timer architecture, manufactured by Texas Instruments. This component operates at 100kHz and is housed in a 14-DIP package. The part is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and procurement planning. Substitute parts must maintain compatibility across electrical specifications, package form factor, and operational parameters to ensure direct replacement capability in existing circuit designs.

Substiute Parts

SA556NG4

Texas InstrumentsIn Stock: 1002SA556NG4 Datasheet

Current PartRFQ

SA556N

STMicroelectronicsIn Stock: 2927SA556N Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SA556NG4 is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Type: 555 Type, Timer/Oscillator (Dual) architecture
• Package / Case: 14-DIP (0.300", 7.62mm) form factor
• Voltage - Supply: 4.5V ~ 16V operating range
• Current - Supply: 20 mA maximum
• Mounting Type: Through Hole
• RoHS Status: ROHS3 Compliant

Allowable Variation:

• Frequency: The SA556NG4 operates at 100kHz. Substitute parts may operate at higher frequencies (500kHz) while maintaining all other electrical and mechanical specifications, as higher frequency capability does not restrict lower-frequency applications.
• Operating Temperature: The SA556NG4 operates from -40°C to 85°C. Substitute parts with extended temperature ranges (-40°C to 105°C) are acceptable, as they provide equal or superior performance across the original operating window.

The SA556N from STMicroelectronics meets all mandatory criteria and allowable variations, qualifying as a direct substitute.

Parameter Comparison

Engineering Selection Recommendations

The SA556N manufactured by STMicroelectronics is qualified as a direct substitute for the SA556NG4. Both components maintain ROHS3 compliance and unlimited moisture sensitivity rating, ensuring regulatory and environmental compatibility. The SA556N provides extended operating temperature range (-40°C to 105°C versus -40°C to 85°C) and higher frequency capability (500kHz versus 100kHz), both of which represent performance enhancements without introducing compatibility constraints. Identical supply voltage range, current specifications, and 14-DIP package form factor ensure mechanical and electrical interchangeability in through-hole PCB applications.

Frequently Asked Questions (FAQ)

Q: Can the SA556N replace the SA556NG4 in existing designs? A: Yes. The SA556N is electrically and mechanically compatible with the SA556NG4. Both components share identical supply voltage range (4.5V ~ 16V), current specifications (20 mA), and 14-DIP package form factor. The SA556N's higher frequency rating and extended temperature range do not restrict its use in applications designed for the SA556NG4.

Q: What is the significance of the frequency difference between these parts? A: The SA556NG4 operates at 100kHz maximum frequency, while the SA556N operates at 500kHz. This difference indicates the maximum oscillation frequency each component can achieve. The SA556N's higher frequency capability is a superset of the SA556NG4's capability and does not prevent its use in lower-frequency applications.

Q: Are there package compatibility concerns? A: No. Both the SA556NG4 and SA556N use identical 14-DIP (0.300", 7.62mm) through-hole packaging. Pin count, spacing, and mounting method are identical, allowing direct PCB substitution without layout modifications.

Q: Do compliance certifications differ between these parts? A: No. Both components are ROHS3 compliant with MSL rating of 1 (Unlimited), ensuring equivalent regulatory and environmental compliance for procurement and assembly processes.

Q: Why is the SA556NG4 listed as obsolete? A: Obsolete status indicates the part is no longer manufactured by Texas Instruments. The SA556N provides continued access to dual 555-type timer/oscillator functionality with equivalent or superior specifications.