LT3097 Linear Regulator Datasheet, Features, Pinout, and Applications

The LT3097 is a low-noise, low-dropout (LDO) linear voltage regulator designed for precision power supply applications. Manufactured by Analog Devices Inc., it delivers excellent performance with high power supply rejection ratio (PSRR), ultra-low noise, and programmable current limit features. The LT3097 is well-suited for sensitive analog systems, RF circuits, instrumentation, and data acquisition systems.

Overview of LT3097

The LT3097 is a dual-channel, low-dropout linear regulator designed to provide both positive and negative outputs with exceptional performance. Developed by Analog Devices, Inc., it incorporates an advanced architecture that delivers ultra-low noise and outstanding power supply rejection ratio (PSRR), making it well-suited for powering sensitive analog or RF circuitry.

Each channel supports output currents up to 500 mA, with typical dropout voltages of 260 mV for the positive rail and 235 mV for the negative rail. The device maintains a low quiescent current—approximately 2.2 mA for the positive side and 2.35 mA for the negative—dropping to as little as 0.3 µA and 3 µA, respectively, in shutdown mode.

The LT3097 features a wide output voltage range: 0 V to +15 V for the positive regulator and 0 V to –19.5 V for the negative. Its error amplifier operates in unity-gain configuration, ensuring consistent performance in terms of output noise, PSRR, bandwidth, and load regulation across the full range of output settings.

The device is stable with a minimum of 10 µF ceramic output capacitance on each channel. Built-in safety features include internal current limiting with foldback protection, thermal shutdown with hysteresis, and both reverse-battery and reverse-current protection on the positive output.

Packaged in a thermally optimized 22-lead 6 mm × 3 mm plastic DFN, the LT3097 is ideal for compact designs requiring precise, quiet dual-rail regulation.

LT3097 Features

• Exceptionally low RMS output noise: 0.8 µV rms (10 Hz to 100 kHz)

• Minimal output noise density: 2 nV/√Hz (positive) and 2.2 nV/√Hz (negative) at 10 kHz

• Low 1/f noise levels: 10 µV p-p (positive) and 3.2 µV p-p (negative) over 0.1 Hz to 10 Hz

• Outstanding PSRR performance: 76 dB (positive) and 74 dB (negative) at 1 MHz

• Supports up to 500 mA output current

• Broad input voltage range: ±1.8 V to ±20 V

• Enhanced noise and PSRR performance with just one capacitor per channel

• Accurate SET pin current: 100 µA with ±1% initial tolerance

• Output voltage set via a single external resistor per channel

• Adjustable current limiting functionality

• Low dropout: 260 mV (positive) and 235 mV (negative)

• Flexible output voltage ranges: 0 V to +15 V (positive) and 0 V to –19.5 V (negative)

• Integrated programmable power good indicator

• Fast startup response

• Precision-enable and undervoltage lockout (UVLO) support

• Internal current limiting with foldback protection

• Operates reliably with a minimum of 10 µF ceramic output capacitance per channel

• Offered in a space-efficient 22-lead, 6 mm × 3 mm low-profile DFN package

LT3097 Pinout

LT3097 Absolute Maximum Ratings

LT3097 Applications

Typical Application Circuit

Bipolar Very Low-Noise Power Supplies:

The LT3097 is ideal for use in bipolar low-noise power supply designs, where both positive and negative voltage rails are needed to support precision analog systems. Its ultra-low output noise and high power supply rejection ratio (PSRR) make it a superior choice for circuits that are highly sensitive to voltage fluctuations and ripple. This includes operational amplifier stages, precision analog front-ends, and high-performance signal processing circuits that require tightly regulated, clean power for optimal accuracy and stability.

RF Power Supplies: Phase-Locked Loops, Voltage-Controlled Oscillators, Mixers, Low-Noise Amplifiers, and Power Amplifiers:

In radio frequency (RF) systems, maintaining a quiet and stable supply voltage is essential to preserve signal integrity and minimize interference. The LT3097’s exceptionally low noise floor and high PSRR make it a strong fit for powering critical RF blocks such as phase-locked loops (PLLs), voltage-controlled oscillators (VCOs), mixers, low-noise amplifiers (LNAs), and power amplifiers (PAs). Its clean output helps suppress spurious tones and unwanted jitter, which is crucial in applications involving high-frequency transmission and reception, such as wireless communication and satellite systems.

Low-Noise Instrumentation:

Precision instrumentation often demands power supplies with ultra-low noise characteristics to ensure that measured signals remain free of unwanted artifacts. The LT3097 addresses this requirement by providing clean, stable power with minimal ripple and exceptional transient response. This makes it particularly well-suited for use in scientific instruments, laboratory test equipment, and high-sensitivity sensor systems where accuracy and signal clarity are paramount.

High-Speed and High-Precision Data Converters:

Analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) operating at high speed or with high resolution can be severely affected by power supply noise. The LT3097 provides a reliable voltage reference for these converters, minimizing distortion and enhancing signal-to-noise ratio (SNR). Its ability to deliver a quiet power rail ensures that the performance of data acquisition systems and signal generation circuits is not compromised by supply-induced errors.

Medical Applications: Imaging and Diagnostics:

In medical imaging and diagnostic equipment, signal integrity and electrical noise suppression are critical to capturing accurate and reliable patient data. The LT3097 supports these systems by delivering clean, low-noise power to sensitive analog circuitry in devices such as ultrasound machines, MRI systems, and patient monitors. Its high precision and quiet operation help meet the stringent requirements of medical-grade electronics, contributing to improved diagnostic confidence and patient outcomes.

Precision Power Supplies:

The LT3097 excels in applications that require finely regulated, low-noise power for precision analog and digital systems. Whether in industrial measurement platforms, aerospace electronics, or research environments, the LT3097 ensures excellent load regulation, low dropout operation, and superior noise performance. It’s an excellent choice wherever component-level power accuracy can directly impact overall system behavior.

Postregulator for Switching Supplies:

When used as a postregulator following a switching DC/DC converter, the LT3097 cleans up the output voltage by suppressing residual ripple and high-frequency switching noise. This hybrid approach combines the efficiency of a switching regulator with the noise performance of a linear regulator. The LT3097 thereby enhances overall power quality, making it highly beneficial in mixed-signal designs, precision analog systems, and any application where noise-sensitive circuits follow a switched-mode power stage.

LT3097 Package

The LT3097 is available in compact, thermally enhanced DFN package. This package allows for efficient thermal management and compact PCB layout in high-performance analog designs.

LT3097 Manufacturer

The LT3097 is manufactured by Analog Devices Inc., a global leader in high-performance analog, mixed-signal, and power management technologies. Analog Devices has earned a reputation for producing precision voltage regulators, amplifiers, data converters, and signal chain solutions that are trusted in industrial, automotive, communications, and healthcare applications.

With decades of innovation, Analog Devices designs components like the LT3097 to meet the stringent requirements of low-noise, high-stability systems. Their rigorous testing standards, extensive documentation, and global technical support infrastructure make ADI products a top choice for engineers building mission-critical systems.

LT3097 Datasheet

The LT3097 Datasheet provides detailed guidance on electrical performance, pin configurations, typical application circuits, and layout recommendations. It is an essential reference for implementing the device in precision analog and low-noise environments.

LT3097 vs. Other Voltage Regulators

Conclusion

The LT3097 Linear Regulator is a high-precision, low-noise LDO ideal for powering analog, RF, and data acquisition systems. Its high PSRR, low output noise, and adjustable voltage range make it a versatile solution for modern precision applications. Backed by the expertise of Analog Devices Inc., the LT3097 ensures exceptional stability, reliability, and efficiency in demanding circuit environments.