LT3905
PRODUCTIONBoost DC/DC Converter with APD Current Monitor
- Part Models
- 4
- 1ku List Price
- Starting From $3.89
Overview
- 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
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
Documentation
Data Sheet 1
User Guide 1
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 Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LT3905EUD#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LT3905EUD#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LT3905IUD#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LT3905IUD#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Apr 11, 2019 - 19_0067 Notification of Wafer Fab Location Change for 0.35 BCD Process |
||
| LT3905EUD#PBF | PRODUCTION | |
| LT3905EUD#TRPBF | PRODUCTION | |
| LT3905IUD#PBF | PRODUCTION | |
| LT3905IUD#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareHardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| Hot Swap Controllers 1 | ||
|
LTC4224-1 LTC4224-2 |
Compact Dual Low Voltage Hot Swap Controller | |
Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LT3905
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.
Evaluation Kits
LT3905 Demo Board | Boost with APD Current Monitor, 2.7V ≤ VIN ≤ 12V, VOUT = 50V @ 2mA