LT3045 ultra-low noise LDO verification board

characteristic

• Input voltage range 1.8-20V
• Output voltage range 0-15V
• Voltage difference 260mV
• Output current 2*0.5A
• Ultra-low RMS noise: 0.8µVRMS (10Hz to 100kHz)
• Ultra-low shot noise: 2nV/√ Hz (at 10kHz)
• Ultra-high PSRR: 76dB (at 1MHz)
• Few peripheral originals
• Quick start function (not implemented)
• Internal current limit

Introduction

• Using DFN 3*3mm package, dual parallel LT3045 design
• Reverse connection diode protection
• R2 and R4 are current limiting resistors and can be short-circuited directly if current limiting is not required.

Notice

• The two tantalum capacitors C5 and C6 are limited by the package size and can only choose 25V withstand voltage, which does not provide enough redundancy.

application

• Power supply for precision voltage and current reference
• Other application scenarios requiring low ripple and low noise

Noise test

Figure 1 below shows the waveform at the input filter capacitor, Figure 2 shows the output capacitor waveform.

The noise is smaller than the noise floor of the oscilloscope