Overview
Features and Benefits
- High Output Voltage: Up to 75V
- Integrated Schottky Diode
- 75V, 350mA Internal Switch
- High Side Fixed Voltage Drop APD Current Monitor
- Adjustable Frequency: 250kHz to 2MHz
- Frequency Synchronization
- Wide VIN Range: 2.7V to 20V
- Constant-Voltage and Constant-Current Regulation
- Programmable Current Limit Protection
- Surface Mount Components
- Low Shutdown Current <1μA
- Internal Soft-Start
- Internal Compensation
- CTRL Pin Allows Output Adjustment with No Polarity Inversion
- 3mm × 3mm 16-Lead QFN Package
Product Details
The LT3571 is a current mode step-up DC/DC converter designed to bias avalanche photodiodes (APDs) in optical receivers with an output voltage up to 75V. The LT3571 features a high side fixed voltage drop APD current monitor with better than 10% relative accuracy over the entire temperature range. The integrated power switch, Schottky diode and APD current monitor allow a small solution footprint and low solution cost. It combines a traditional voltage loop and a unique current loop to operate as a constant-current source or constant-voltage source. The inductor-based topology ensures an input free from switching noise. The integrated high side current monitor produces a current proportional to the APD current with better than 10% relative accuracy over four decades of dynamic range in the input range of 250nA to 2.5mA. This current can be used as a reference to provide a digitally programmed output voltage via the CTRL pin. The LT3571 is available in the tiny footprint (3mm × 3mm) 16-lead QFN package.
Applications
- APD Bias
- PIN Diode Bias
- Optical Receivers and Modules
- Fiber Optic Network Equipment
Product Categories
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
Documentation & Resources
-
R530 Reliability Data3/26/2018
-
DC1423A - Demo Manual9/24/2009
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

LTspice Simulations
Models for the following parts are available in LTspice:
Product Recommendations
LT3571 Companion Parts
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
---|---|---|---|---|
LT3571EUD#PBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
LT3571EUD#TRPBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
LT3571IUD#PBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
LT3571IUD#TRPBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
Wafer Fabrication Data | R530 Reliability Data |
Support & Discussions
LT3571 Discussions
Sample & Buy
Ordering FAQs
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Buy Now Pricing
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List Pricing
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Lead Times
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Sampling
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.