LTC3873-5 - No RSENSE Constant Frequency Current Mode Boost/Flyback/SEPIC DC/DC Controller
Features
- VIN and VOUT Limited Only by External Components
- Internal or Programmable External Soft-Start
- Constant Frequency 200kHz Operation
- Adjustable Current Limit
- Current Sense Resistor Optional
- ±1.5% Voltage Reference Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- 4.1V Undervoltage Threshold for Logic Level
MOSFET Applications - Low Quiescent Current: 300µA
- Low Profile (1mm) ThinSOT™ and (0.75mm) 2mm × 3mm DFN Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3873-5 is a constant frequency current mode controller for boost, flyback or SEPIC DC/DC converters designed to drive an N-channel MOSFET for high input and output voltage converter applications.
The LTC3873-5 provides ±1.5% output voltage accuracy and consumes only 300μA quiescent current during normal operation and only 50μA during micropower start-up. Using a 9.3V internal shunt regulator, the LTC3873-5 can be powered from a high input voltage through a resistor or it can be powered directly from a low impedance DC voltage of 9V or less. Soft-start can be programmed using an external capacitor.
The LTC3873-5 is available in 8-lead ThinSOT and 2mm × 3mm DFN packages.
| LTC3873 | LTC3873-5 | |
|---|---|---|
| VCC UV+ | 8.4V | 3.9V |
| VCC UV- | 4V | 2.9V |
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC3873EDDB-5#PBF | 3x2 DFN-8 | DDB | E | 05-08-1702 | Yes |
| LTC3873EDDB-5#TRMPBF | 3x2 DFN-8 | DDB | E | 05-08-1702 | Yes |
| LTC3873EDDB-5#TRPBF | 3x2 DFN-8 | DDB | E | 05-08-1702 | Yes |
| LTC3873ETS8-5#PBF | SOT-23 | TS8 | E | 05-08-1637 | Yes |
| LTC3873ETS8-5#TRMPBF | SOT-23 | TS8 | E | 05-08-1637 | Yes |
| LTC3873ETS8-5#TRPBF | SOT-23 | TS8 | E | 05-08-1637 | Yes |
| LTC3873IDDB-5#PBF | 3x2 DFN-8 | DDB | I | 05-08-1702 | Yes |
| LTC3873IDDB-5#TRMPBF | 3x2 DFN-8 | DDB | I | 05-08-1702 | Yes |
| LTC3873IDDB-5#TRPBF | 3x2 DFN-8 | DDB | I | 05-08-1702 | Yes |
| LTC3873ITS8-5#PBF | SOT-23 | TS8 | I | 05-08-1637 | Yes |
| LTC3873ITS8-5#TRMPBF | SOT-23 | TS8 | I | 05-08-1637 | Yes |
| LTC3873ITS8-5#TRPBF | SOT-23 | TS8 | I | 05-08-1637 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3873EDDB-5#PBF | 3x2 DFN-8 | E | $1.79 | Yes | ||
| LTC3873EDDB-5#TRMPBF | 3x2 DFN-8 | E | $1.79 | $1.30 | Yes | |
| LTC3873EDDB-5#TRPBF | 3x2 DFN-8 | E | $1.79 | $1.25 | Yes | |
| LTC3873ETS8-5#PBF | SOT-23 | E | $1.79 | Yes | ||
| LTC3873ETS8-5#TRMPBF | SOT-23 | E | $1.79 | $1.30 | Yes | |
| LTC3873ETS8-5#TRPBF | SOT-23 | E | $1.79 | $1.25 | Yes | |
| LTC3873IDDB-5#PBF | 3x2 DFN-8 | I | $1.84 | Yes | ||
| LTC3873IDDB-5#TRMPBF | 3x2 DFN-8 | I | $1.84 | $1.34 | Yes | |
| LTC3873IDDB-5#TRPBF | 3x2 DFN-8 | I | $1.84 | $1.29 | Yes | |
| LTC3873ITS8-5#PBF | SOT-23 | I | $1.84 | Yes | ||
| LTC3873ITS8-5#TRMPBF | SOT-23 | I | $1.84 | $1.34 | Yes | |
| LTC3873ITS8-5#TRPBF | SOT-23 | I | $1.84 | $1.29 | Yes | |
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.Click here to view our complete list of demo boards
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3873IDDB-5#PBF | 3x2 DFN-8 | I | $1.84 | Yes | ||
| LTC3873IDDB-5#TRMPBF | 3x2 DFN-8 | I | $1.84 | $1.34 | Yes | |
| LTC3873IDDB-5#TRPBF | 3x2 DFN-8 | I | $1.84 | $1.29 | Yes | |
| LTC3873ITS8-5#PBF | SOT-23 | I | $1.84 | Yes | ||
| LTC3873ITS8-5#TRMPBF | SOT-23 | I | $1.84 | $1.34 | Yes | |
| LTC3873ITS8-5#TRPBF | SOT-23 | I | $1.84 | $1.29 | Yes | |
| Buy Now • Request Samples | ||||||
Applications
- Telecom Power Supplies
- Automotive Power Supplies
- PoE Applications
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LTC3873
LTC3873-5
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
