Analog DevicesLT3097ADJC#PBFLinear Regulators

The LT3097 is a dual, positive and negative, high-performance, low-dropout linear regulator featuring Analog Devices, Inc., ultralow noise and ultra-high power supply rejection ratio (PSRR) architecture for powering noise-sensitive applications. Each regulator delivers up to 500 mA with a typical 260 mV/235 mV (positive/negative) dropout voltage.

The operating quiescent current of the LT3097 is nominally 2.2 mA/2.35 mA (positive/negative) and drops to 0.3 μA/3 μA (positive/negative) in shutdown. It has a wide output voltage range (0 V to 15 V, positive and 0 V to -19.5 V, negative) error amplifier that operates in unity-gain and provides virtually constant output noise, PSRR, bandwidth and load regulation, independent of the programmed output voltage.

LT3097 is stable with a minimum 10 μF ceramic output capacitor for each channel. Built-in protection includes internal current limit with foldback and thermal limit with hysteresis. The positive regulator also includes reverse-battery protection and reverse-current protection. The LT3097 is available in a thermally enhanced, 22-lead 6 mm × 3 mm, Plastic dual-flat no-leads (DFN) package.

Key Features and Benefits

• Ultra-low output RMS noise: 0.8 μVRMS (10 Hz to 100 kHz)
• Ultra-low output noise spectral density: 2 nV/√Hz (Positive) and 2.2 nV/√Hz (Negative) at 10 kHz
• Ultra-low 1/f noise: 10 μVp-p (Positive) and 3.2 μVp-p (Negative) (0.1 Hz to 10 Hz)
• Ultra-high PSRR: 76 dB (Positive) and 74 dB (Negative) at 1 MHz
• Output current: 500 mA
• Wide input voltage range: ±1.8 V to ±20 V
• Single capacitor per channel improves noise and PSRR
• SET pin current: 100 μA, ±1% initial accuracy
• Single resistor per channel programs output voltage
• Programmable current limit
• Low-dropout voltage: 260 mV (Positive) and 235 mV (Negative)
• Output voltage range: 0 V to 15 V (Positive) and 0 V to –19.5 V (Negative)
• Programmable power good
• Fast start-up capability
• Precision enable/undervoltage lockout (UVLO)
• Internal current limit with foldback
• Minimum output capacitor: 10 μF ceramic
• Compact, low-profile, 22-lead, 6 mm × 3 mm, Plastic DFN package

Applications

• Bipolar very low-noise power supplies
• RF power supplies: phase-locked loops, voltage-controlled oscillators, mixers, low-noise amplifiers, and power amplifiers
• Low-noise instrumentation
• High-speed and high-precision data converters
• Medical applications: imaging and diagnostics
• Precision power supplies
• Postregulator for switching supplies

Evaluation Board

The LT3097 can be evaluated with the EVAL-LT3097-AZ.

Block Diagrams and Tables