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LT3905: Boost DC/DC Converter with APD Current Monitor Data Sheet8/8/2014PDF252K
Overview
Features and Benefits
- 65V, 350mA Internal DMOS Switch
- Integrated Schottky Diode
- 2% Accurate APD Current Monitoring Over the 3μA to 3mA Range
- Single Resistor Programs Maximum APD Current
- Fast APD Current Limiter with Indicator
- Programmable Loss-of-Signal Indicator
- CTRL Pin Adjusts Output Voltage
- Programmable VIN Undervoltage Lockout
- High Efficiency Step-Up Converter
- Selectable 1MHz/2MHz Switching Frequency
- Internally Compensated
- Internal Soft-Start
- 2.7V to 12V VIN Range
- Low Shutdown Current: <1μA
Product Details
The LT3905 is a fixed frequency current-mode step-up converter designed to bias avalanche photodiodes (APD) in optical receivers. The LT3905 features high side APD current monitoring over four decades of dynamic range with better than 2% relative accuracy over the 3μA to 3mA range.
The maximum APD current is programmed with a single resistor, and a fast current limiter with indicator protects the APD during overload conditions. Adjustable output voltage provides dynamic bias control, and an adjustable loss-of-signal indicator flags low APD current.
Coupled with the integrated DMOS power switch and Schottky rectifier, the LT3905 provides a compact total solution with few external components and low solution cost. Constant switching frequency results in predictable output noise that is easy to filter.
The LT3905 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 (1)
Documentation & Resources
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R570 Reliability Data3/23/2018PDF415 K
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DC1956A - Demo Manual2/3/2014PDF174K
Tools & Simulations
LTspice
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LTspice Simulations
Models for the following parts are available in LTspice:
LT3905
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 |
|---|---|---|---|---|
| LT3905EUD#PBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
| LT3905EUD#TRPBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
| LT3905IUD#PBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
| LT3905IUD#TRPBF | Material Declaration | Reliability Data | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | |
| Wafer Fabrication Data | R570 Reliability Data |
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Support & Discussions
LT3905 Discussions
Sample & Buy
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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.