Analog Devices Inc. LT3092IST#PBF

LT3092IST#PBF Product Summary

The LT3092IST#PBF is an advanced programmable two-terminal current source designed and manufactured by Analog Devices Inc. As part of the broader LT3092 family, it offers a highly integrated solution intended for precision current regulation tasks, making it suitable for a wide range of industrial, automotive, and instrumentation applications. With its ability to set output currents from 0.5mA to 200mA using just two resistors, this device aims to simplify engineering workflows by delivering robust, stable, and accurate current sourcing capabilities within a compact SOT-223-3 package. The LT3092IST#PBF is fully RoHS3 and REACH-compliant, operating over an extended temperature range from –40°C to +125°C, meeting the critical requirements of modern electronic system designs.

LT3092IST#PBF Main Attributes and Function Overview

The primary function of the LT3092IST#PBF is to serve as a highly accurate current source with programmability at its core. By leveraging a unique resistor ratio programming mechanism and an integrated 10μA SET pin current source, the LT3092IST#PBF enables designers to tailor the output current with minimal component count and complexity. Its wide input voltage range (1.2V to 40V) provides substantial flexibility for various supply rail scenarios, and the device maintains regulation across its full rated load spectrum.

Notably, the LT3092IST#PBF is stable without the need for input or output capacitors, delivering high DC and AC output impedance—an important advantage in applications requiring precise current control under dynamic conditions. The programmable nature of the device allows it to be configured as a floating current source, ground-referenced source, or as an in-line current limiter, supporting both standard and intrinsic safety circuit architectures.

The device incorporates essential protections such as reverse-battery, reverse-current, current limiting, and thermal shutdown. This comprehensive suite of features ensures safe operation under fault conditions and enhances long-term device reliability.

LT3092IST#PBF Electrical Specifications and Performance Summary

The LT3092IST#PBF is engineered to deliver consistent performance even over a broad temperature range. Key specifications include:

Output Current: Adjustable from 0.5mA to 200mA

Output Current Accuracy: 1% initial set pin current accuracy; line regulation typically <0.001%/V

Input Voltage Range: 1.2V to 40V

Dropout Voltage: 1.22V (10mA load) to 1.45V (200mA load), ensuring efficient operation near supply minimums

Load Regulation: Better than 10ppm/V across full input voltage span

Operating Temperature: –40°C to +125°C junction temperature

Output Noise: Extremely low (0.7nA RMS from 10Hz to 100kHz), with the option for further improvement via external capacitance

Ripple Rejection: Up to 90dB at 120Hz, enabling use in noise-sensitive environments

The device is designed for indefinite output short-circuit duration and includes overtemperature protection, ensuring robust performance in demanding applications. The minimum load current is specified at 300–500μA, which also reflects the device’s quiescent current requirement.

LT3092IST#PBF Packaging Details, Pin Configuration, and Thermal Management

The LT3092IST#PBF is offered in a SOT-223-3 surface-mount package, supporting straightforward PCB integration in high-density layouts. The device’s thermal performance is defined by a maximum junction temperature of 125°C and thermal resistance values of θJA = 24°C/W and θJC = 15°C/W (dependent on PCB mounting).

The simple pinout features IN (input), SET (programming), and OUT (current output), with the tab directly connected to OUT. Effective thermal management is achieved by optimizing PCB copper area attached to the OUT tab, which also serves to enhance power dissipation for sustained full-load operation. The device is rated for standard lead-free reflow soldering at temperatures up to 300°C (SOT-223 package).

LT3092IST#PBF Application Examples and Engineering Solutions

The versatility of the LT3092IST#PBF is evident in its wide range of possible applications. Its ability to operate as a floating or ground-referenced current source makes it ideal for driving remote sensors, biasing LEDs, powering photodiodes, or acting as a precision current limiter for sensitive circuitry in industrial or automotive designs.

The high output impedance and strong current regulation performance make the LT3092IST#PBF particularly well-suited for in-line current source applications, intrinsically safe circuit designs, and accurate analog measurement systems that demand low noise, low drift, and high reliability.

LT3092IST#PBF Design Principles and Common Application Schematics

Implementing the LT3092IST#PBF in a circuit is straightforward. The output current is set using two external resistors, selected according to the relationship dictated by the internal 10μA reference current on the SET pin. Typical designs involve placing one resistor between IN and SET, and another between SET and OUT. The ratio of these resistors directly sets the desired output current, allowing for flexible adjustment according to the needs of the application.

The device’s stability without external capacitors simplifies PCB design, while the absence of input/output capacitors promotes higher reliability and eases layout constraints in sensitive analog applications. For further noise reduction, an optional small-value capacitor can be placed in parallel with the programming resistor across the SET pin.

LT3092IST#PBF Safeguard Mechanisms and Reliability Analysis

The LT3092IST#PBF incorporates a robust suite of protection mechanisms to ensure safe operation under both normal and abnormal conditions. Internal reverse-battery and reverse-current protection guard against accidental polarity reversal and harmful backflow currents. The device also features current limiting and integrated thermal shutdown, allowing it to safely withstand output short circuits or excessive thermal events without suffering permanent damage.

With an indefinite output short-circuit rating and reliable performance over a wide temperature range, the LT3092IST#PBF meets the reliability requirements of automotive, industrial, and high-availability systems. Manufacturing and testing conform to rigorous standards, and the device is compliant with RoHS3 and REACH environmental directives.

LT3092IST#PBF Alternative or Substitute Models

For procurement specialists and design engineers, it is prudent to consider suitable alternatives should the LT3092IST#PBF become unavailable. Comparable devices in the marketplace feature similar programmable current source functionality, wide input voltage ranges, and comparable current accuracy. When selecting an equivalent or replacement model, key parameters to match include output current range, voltage compliance, thermal characteristics, package type, and available protection features. Cross-references should be made specifically against precision programmable two-terminal current sources from reputable manufacturers to ensure maintainability of system performance.

Conclusion

The LT3092IST#PBF from Analog Devices stands out as a highly accurate, flexible, and robust programmable current source regulator. With its simple programming interface, broad input voltage range, and versatile package, it addresses the critical needs of modern analog and power supply systems where precision current control, reliability, and safety are paramount. By combining advanced protection features with minimal external component requirements, the LT3092IST#PBF offers procurement and design engineers an optimal solution for both new designs and system upgrades in demanding environments.