Data Sheet

LT3097

Dual 500mA, Positive/Negative, Ultra-Low Noise, Ultra-High PSRR Low Dropout

Linear Regulator

Rev. 0

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FEATURES

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Ultra-low output RMS noise: 0.8 μV rms (10 Hz to 100 kHz)

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Ultra-low output noise spectral density: 2 nV/√Hz (Positive) and

2.2 nV/√Hz (Negative) at 10 kHz

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Ultra-low 1/f noise: 10 µV p-p (Positive) and 3.2 µV p-p (Nega-

tive) (0.1 Hz to 10 Hz)

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Ultra-high PSRR: 76 dB (Positive) and 74 dB (Negative) at 1

MHz

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Output current: 500 mA

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Wide input voltage range: ±1.8 V to ±20 V

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Single capacitor per channel improves noise and PSRR

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SET pin current: 100 µA, ±1% initial accuracy

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Single resistor per channel programs output voltage

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Programmable current limit

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Low-dropout voltage: 260 mV (Positive) and 235 mV (Negative)

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Output voltage range: 0 V to 15 V (Positive) and 0 V to –19.5 V

(Negative)

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Programmable power good

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Fast start-up capability

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Precision enable/undervoltage lockout (UVLO)

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Internal current limit with foldback

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Minimum output capacitor: 10 µF ceramic

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Compact, low-profile, 22-lead, 6 mm × 3 mm, Plastic DFN

package

TYPICAL APPLICATION

Figure 1. Typical Application

APPLICATIONS

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Bipolar very low-noise power supplies

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RF power supplies: phase-locked loops, voltage-controlled oscil-

lators, mixers, low-noise amplifiers, and power amplifiers

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Low-noise instrumentation

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High-speed and high-precision data converters

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Medical applications: imaging and diagnostics

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Precision power supplies

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Postregulator for switching supplies

GENERAL DESCRIPTION

The LT3097 is a dual, positive and negative, high-performance,

low-dropout linear regulator featuring Analog Devices, Inc., ultra-

low noise and ultra-high power supply rejection ratio (PSRR) archi-

tecture for powering noise-sensitive applications. Each regulator

delivers up to 500 mA with a typical 260 mV/235 mV (positive/nega-

tive) dropout voltage.

Operating quiescent current is nominally 2.2 mA/2.35 mA (posi-

tive/negative) and drops to 0.3 µA/3 µA (positive/negative) in shut-

down. The LT3097 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 protec-

tion. The LT3097 is available in a thermally enhanced, 22-lead 6

mm × 3 mm, Plastic dual-flat no-leads (DFN) package.

Figure 2. PSRR vs. Frequency