LS5912 TO-78 6L

Overview

The LS5912 is a monolithic dual N-channel JFET amplifier designed as an improved replacement for legacy discrete devices. It features low noise performance with equivalent input noise voltage of 4 nV/√Hz at 10kHz and high transconductance (gfs) ranging from 4000 to 10000 µS at 1kHz. The device supports a gate-to-source breakdown voltage of -25V and operates within a junction temperature range of -55°C to +150°C. Key electrical characteristics include a typical drain-to-source saturation current (IDSS) of 7-40 mA and a common mode rejection ratio of 85 dB.

Feature Summary

• Monolithic integration of dual matched N-channel JFETs for precise differential applications
• Ultra-low noise performance suitable for sensitive signal processing
• High transconductance ensuring robust amplification capabilities
• Tight matching parameters including differential cutoff voltage and forward transconductance ratios

Applications

• Low-noise preamplifier stages in instrumentation systems
• Precision analog front-ends requiring high common-mode rejection
• Wideband amplifier circuits utilizing high transconductance
• Direct replacements for legacy 2N5911/2N5912 discrete designs

Procurement Notes

Verify the specific package variant, as the LS5912 is available in multiple configurations including TO-78, SOT-23, PDIP, and SOIC. Confirm that the ordering suffix corresponds to the required mechanical footprint and pinout arrangement. Ensure compatibility with existing board layouts when substituting for older discrete components or different package styles.

Selection Notes

Select the LS5912 when superior noise figures and tighter parameter matching are required compared to standard discrete JFET pairs. Consider the operating frequency range, as transconductance varies significantly between 1kHz and 100MHz. Evaluate thermal management requirements given the 500mW continuous power dissipation limit and derating factors above 25°C ambient temperature.

Part Context

Linear Integrated Systems manufactures the LS5912 as part of a family of precision semiconductor components, including the LS5911 and LS5912C. These devices leverage process expertise derived from historical developments at companies such as Intersil and Union Carbide. The product line focuses on providing high-quality, matched discrete and integrated components for demanding analog applications.

Replacement Considerations

The LS5912 is explicitly documented as an improved replacement for SILICONIX, FAIRCHILD, and NATIONAL 2N5911 and 2N5912 devices. Designers transitioning from these legacy parts should verify pinout compatibility if using different packages, as the monolithic integration offers enhanced matching over discrete equivalents.

FAQ

What is the typical equivalent input noise voltage at 10kHz?

The typical equivalent input noise voltage (en) is 4 nV/√Hz at 10kHz.

How does the transconductance vary with frequency?

The forward transconductance (gfs) is specified between 4000 and 10000 µS at 1kHz, and increases to a typical value of 7000 µS at 100MHz under specific bias conditions.

What is the maximum gate-to-source voltage rating?

The absolute maximum gate-to-source voltage is rated at -25V.