PN4118

Overview

The PN4118 is a high-speed switching NPN silicon transistor manufactured by Fairchild Semiconductor. It is housed in a compact SOT-23 surface-mount package designed for low current DC and audio applications. The device provides excellent performance as an input stage for sub-picoamp instrumentation or any high impedance signal sources. It is sourced from process 53.

Feature Summary

• High-speed switching capability suitable for demanding electronic circuits
• Designed for low current DC and audio applications
• Optimized for use as an input stage in sub-picoamp instrumentation
• Compatible with high impedance signal sources

Applications

• Sub-picoamp instrumentation input stages
• High impedance signal source interfacing
• Low current DC switching applications
• Audio circuit applications

Procurement Notes

Verify the manufacturer designation, as Fairchild Semiconductor's discrete component portfolio was acquired by ON Semiconductor. Confirm that the specific PN4118 part number corresponds to the original Fairchild specifications rather than a generic equivalent. Ensure the SOT-23 package and lead-free status match the required design constraints before finalizing procurement.

Selection Notes

Select this component when designing circuits requiring high-speed switching with low current consumption. It is particularly suitable for applications involving sub-picoamp instrumentation where high impedance signal sources are present. The SOT-23 package makes it ideal for space-constrained surface-mount designs. Consider thermal dissipation limits if operating near maximum ratings.

Part Context

The PN4118 belongs to a family of N-channel switch transistors that includes the MMBF4117 and MMBF4119. These devices share similar design goals for low current DC and audio applications. They are all sourced from process 53 and utilize the SOT-23 3L package. The top marks differentiate them: 61a for MMBF4117, 61c for MMBF4118, and 61e for MMBF4119.