SINGLE, LOW NOISE, HIGH GAIN, N-CHANNEL JFET AMPLIFIER < Back J/SST201 Series SINGLE, LOW NOISE, HIGH GAIN, N-CHANNEL JFET AMPLIFIER The J/SST201 Series Single, Low Noise, High Gain, N-Channel JFET Amplifier is a direct replacement for the Fairchild, NXP, and Siliconix-Vishay equivalent part. It is ideal for High Gain, Low Noise Applications. Available in the TO-92 3L and SOT-23 3L RoHS package, as well as die form. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: J201 TO-92 3L RoHS J202 TO-92 3L RoHS J204 TO-92 3L RoHS SST201 SOT-23 3L RoHS SST202 SOT-23 3L RoHS SST204 SOT-23 3L RoHS J201 Die J202 Die J204 Die Datasheet Spice Model Application Notes

< Back Interfacing Sensors & Transducers Introduction Abstract: A discussion of methods of amplifying and signal-conditioning for sensors with low level outputs in the presence of high ambient electrical noise sources. Advantages and disadvantages of some common amplifier circuits are considered. Read More

< Back LS844 App Note Introduction Introduction For circuits designed to work with high impedance sources, ranging from electrometers to microphone preamplifiers, the use of a low-noise, high-impedance device between the input and the op amp is needed in order to optimize performance. At first glance, one of Linear Systems’ most popular parts, the LSK389 ultra-low-noise dual JFET would appear to be a good choice for such an application. The part’s high input impedance (1 T) and low noise (1 nV/√Hz at 1kHz and 2mA drain current) enables power transfer while adding almost no noise to the signal. But further examination of the LSK389’s specification shows an input capacitance of over 20pF. This will cause intermodulation distortion as the circuit’s input signal increases in frequency if the source impedance is high. This is because the JFET junction capacitances are nonlinear. This will be especially the case where common source amplifier arrangements allow the Miller effect to multiply the effective value of the gatedrain capacitance. Further, the LSK389’s input impedance will fall to a lower value as the frequency increases relative to a part with lower input capacitance. A better design choice is Linear Systems’ LS844. Though the LS844 has slightly higher noise (2.5 nV/√Hz vs. 1.0 nV/√Hz) its much lower input capacitance of only 4pF means that it will maintain its high input impedance as the frequency of the input signal rises. More importantly, using the lower-capacitance LS844 will create a circuit that is much less susceptible to intermodulation distortion than one using the LSK389. The LS844’s lower gate-to-drain capacitance enables more effective, elegant audio circuit designs. The relatively high capacitance of the LSK389 often requires designers to use a cascode circuit to provide the ability to handle higher bandwidths without intermodulation distortion. The cascode does this by eliminating the Miller effect that can multiply the effective gate-drain capacitance and its associated nonlinear effects. However, the cascode adds complexity and noise contributed by the cascode transistors. The LS844 is an N-channel dual low-noise, lowcapacitance, tightly matched monolithic field effect transistor. It features: • 3ms transconductance at 2mA drain current • 1000 G input impedance • 60V breakdown voltage • gate-drain capacitance of only 1.5pF • 4pF input capacitance • 2.5 nV/√Hz noise at 1kHz • best low-noise/low-capacitance combination in the industry • lowest input capacitance per unit gate length in the industry • lowest noise for a given gate length in the industry • tight Vgs matching at operating bias The LS844 is particularly well suited to low-noise, highgain audio and instrumentation circuits operating from battery voltages up to 60 volts. 48V phantom-powered circuits, like those used in microphone preamplifiers, are especially benefited by the features of the LS844. Low operating Vgs, high gm, tight matching, low noise and low capacitance make it well-suited to numerous audio and instrumentation applications. Sensors, which play such an important role in today’s world, benefit greatly from the performance delivered by the LS844. Such sensor technologies include piezo, quartz, condenser, electret, and MEMs devices. These devices benefit from the LS844’s combination of low input capacitance and low noise. Electrometer applications also benefit from these characteristics. Read More

MONOLITHIC DUAL, PICO AMP LOW LEAKAGE DIODES < Back ID100 Series ID100 SERIES MONOLITHIC DUAL, PICO AMP LOW LEAKAGE DIODES The ID100 Series Monolithic Dual, Pico Amp Low Leakage Diodes is a direct replacement for the Intersil part series. It is ideal for Pico Amp, Ultra Low Leakage, Protection Diode Applications. The part series is available in the TO-71 6L RoHS and TO-78 6L RoHS package, as well as in die form. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: ID100 TO-71 6L RoHS ID101 TO-78 6L RoHS ID100 TO-71 6L RoHS ID101 TO-78 6L RoHS Datasheet Spice Model Application Notes

CURRENT REGULATING DIODE < Back SST500 Series CURRENT REGULATING DIODE The SST500 Series Current Regulating Diode is a direct replacement for the Siliconix-Vishay SST500 Series. It is ideal for current-limiting and constant-current applications. It is available in the SOT-23 3L RoHS package, as well as bare die. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: SST500 SOT23 3L RoHS SST501 SOT23 3L RoHS SST502 SOT23 3L RoHS SST503 SOT23 3L RoHS SST504 SOT23 3L RoHS SST505 SOT23 3L RoHS SST506 SOT23 3L RoHS SST507 SOT23 3L RoHS SST508 SOT23 3L RoHS SST509 SOT23 3L RoHS SST510 SOT23 3L RoHS SST511 SOT23 3L RoHS J500 Die J501 Die J502 Die J503 Die J504 Die J505 Die J506 Die J507 Die J508 Die J509 Die J510 Die J511 Die Datasheet Spice Model Application Notes

< Back Current Regulating Diodes Introduction Abstract: Many analog circuit designs have the need for current regulation. Examples include circuits that process signals from sensors, circuits that amplify, and voltage reference or regulators. Current regulation can be referred to as a current source or a Norton device/equivalent circuit (cf. Thevenin equivalent circuit). Read More

Linear Systems designs and manufactures the highest-performance line of monolithic dual JFETs in the industry. Contact us for a quote! Back 2N5564 Series LOW NOISE, MONOLITHIC DUAL, N-CHANNEL JFET The 2N5564 Series is a Low Noise, Monolithic Dual, N-Channel JFET. These matched pairs of JFETs are mounted in a TO-71 package. The two-chip design reduces parasitics for good performance at high frequency while ensuring extremely tight matching. This series features high breakdown voltage, high gain, and <5 mV offset between the two die. It is a Pin-for-Pin Replacement for Siliconix-Vishay 2N5564 Series, available in the TO-71 6L RoHS package, as well as bare die. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: 2N5564 TO-71 6L RoHS 2N5565 TO-71 6L RoHS 2N5566 TO-71 6L RoHS 2N5564 Die 2N5565 Die 2N5566 Die Datasheet Spice Model Application Notes

< Back What are Current Regulating Diodes Linear Systems Oct 7, 2024 Current regulating diodes, also known as constant current diodes or current limiting diodes, are electronic components that control the amount of electrical current flowing through a circuit. They work by maintaining a constant voltage across themselves despite changes in the load resistance. Current Regulating Diodes Current regulating diodes, also known as constant current diodes or current limiting diodes, are electronic components that control the amount of electrical current flowing through a circuit. They work by maintaining a constant voltage across themselves despite changes in the load resistance. How do they work? A standard diode allows current to flow freely in one direction and blocks it in the other direction. In contrast, a current regulating diode has a larger depletion region and a lower reverse breakdown voltage, which allows for more precise control of the current flow. When used in series with a load, the current regulating diode maintains a stable voltage drop across itself by varying its own resistance depending on the current flow. This means that as the load resistance changes, the voltage drop across the diode remains constant and therefore maintains a consistent current flow. Applications Current regulating diodes are commonly used in circuits where stable and precise current control is necessary, such as in LED lighting systems, battery charging circuits, and laser diode drivers. They can also be used as protection devices to limit the amount of current flowing through sensitive components. In addition, these diodes are often utilized in adjustable power supplies to regulate the output current and prevent damage to connected devices. Types of Current Regulating Diodes There are two main types of current regulating diodes: Zener diodes and avalanche diodes. Zener diodes operate in the reverse breakdown region, where they maintain a constant voltage despite changes in current flow. This makes them ideal for use as voltage regulators. Avalanche diodes, on the other hand, operate in the avalanche breakdown region and are used for higher voltage applications. They have a steeper current-voltage characteristic compared to Zener diodes, allowing for more precise control of the current flow. Advantages and Disadvantages The main advantage of using current regulating diodes is their ability to provide stable and accurate current control without the need for additional external components. This saves space and simplifies circuit design. However, one disadvantage is that these diodes can be sensitive to changes in temperature, which can affect their current regulation capabilities. In addition, they have a limited maximum current handling capacity, so they may not be suitable for high power applications. Conclusion In conclusion, current regulating diodes are essential components in many electronic circuits where precise and stable current control is necessary. They come in various types and offer advantages such as simplicity of use and compact size. However, care must be taken when using these diodes to ensure proper operation under different conditions. With continued advancements in technology, it is likely that we will see further improvements and developments in the field of current regulating diodes. So next time you encounter a circuit that requires precise current control, consider using a current regulating diode to achieve optimal performance. With their unique properties and benefits, these diodes are sure to play a significant role in the future of electronics. With the ever-growing demand for more efficient and reliable electronic devices, it is important to have a thorough understanding of different electronic components such as current regulating diodes. By having knowledge about their operation, advantages and limitations, you can make informed decisions when designing circuits for various applications. So keep exploring and learning about these fascinating components and discover new ways to incorporate them into your designs.

Linear Systems designs and manufactures the highest-performance line of monolithic dual JFETs in the industry. Contact us for a quote! Back 2N/LS5905 Series LOW-LEAKAGE, LOW-DRIFT, MONOLITHIC DUAL, N-CHANNEL JFET AMPLIFIER The 2N/LS5905 Series Low Leakage, Low Drift, Monolithic Dual N-Channel JFET Amplifier features tight matching and low drift over temperature specifications. The series is targeted for use in a wide range of precision instrumentation applications where tight tracking is required. Linear Systems’ version of this part series is a direct, pin-for-pin replacement of the Intersil part. Available in the TO-78 7L RoHS and SOIC 8L RoHS package, as well as bare die. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: LS5905 TO-78 7L RoHS LS5906 TO-78 7L RoHS LS5907 TO-78 7L RoHS LS5908 TO-78 7L RoHS LS5909 TO-78 7L RoHS 2N5905 TO-78 7L RoHS 2N5906 TO-78 7L RoHS 2N5907 TO-78 7L RoHS 2N5908 TO-78 7L RoHS 2N5909 TO-78 7L RoHS LS5905 SOIC 8L RoHS LS5906 SOIC 8L RoHS LS5907 SOIC 8L RoHS LS5908 SOIC 8L RoHS LS5909 SOIC 8L RoHS Datasheet Spice Model Application Notes

SINGLE, ULTRA-LOW NOISE, P-CHANNEL JFET AMPLIFIER < Back LSJ/SST74 Series SINGLE, ULTRA-LOW NOISE, P-CHANNEL JFET AMPLIFIER The LSJ/SST74 Single, Ultra-Low noise, P-Channel JFET Amplifier is a direct replacement for the Toshiba 2SJ74. It is ideal for Ultra-Low Noise Audio/Acoustic Applications. Available in the TO-92 3L RoHS, SOT-89 3L RoHS, as well as in die form. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information: Below are the options you have when ordering this part series: LSJ74A TO-92 3L RoHS LSJ74B TO-92 3L RoHS LSJ74C TO-92 3L RoHS LSJ74D TO-92 3L RoHS SST74A SOT-23 3L RoHS SST74B SOT-23 3L RoHS SST74C SOT-23 3L RoHS SST74D SOT-23 3L RoHS Datasheet Spice Model Application Notes

MONOLITHIC DUAL AND SINGLE, PNP TRANSISTOR < Back LS3550 Series MONOLITHIC DUAL AND SINGLE, PNP TRANSISTOR Previous Next

< Back J201 App Note Introduction Linear Systems products enable customers to build the lowest-noise signal chains possible. The J201 N-channel JFET is optimized for high gain. The part is particularly suitable for use in low power or high impedance amplifiers. Read More