LT4256-3 - Positive High Voltage Hot Swap Controller with Open-Circuit Detect
Features
- Allows Safe Board Insertion and Removal from a Live Backplane
- Controls Supply Voltage from 10.8V to 80V
- Foldback Current Limiting
- Open Circuit and Overcurrent Fault Detect
- Drives an External N-Channel MOSFET
- Automatic Retry or Latched Off Operation After Overcurrent Fault
- Programmable Supply Voltage Power-Up Rate
- Open MOSFET Detection
- 1% Over and Undervoltage Detection Accuracy
- Available in a 16-Lead SSOP Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LT4256-3 is a high voltage Hot Swap™ controller that allows a board to be safely inserted and removed from a live backplane. An internal driver controls the high side N-channel MOSFET gate for supply voltages ranging from 10.8V to 80V. The part features an open-circuit detect (OPEN) output that indicates abnormally low load current conditions.
The LT4256-3 also features an adjustable analog foldback current limit. If the supply remains in current limit for more than a programmable time, the N-channel MOSFET shuts off, the PWRGD output asserts low and the LT4256-3 either automatically restarts after a time-out delay or latches off until the UV pin is cycled low (depending on the status of the RETRY pin).
The PWRGD output indicates when the output voltage rises above a programmed level. An external resistor string from VCC provides programmable undervoltage and overvoltage protection.
The LT4256-3 is available in a 16-lead SSOP package.
| Retry / Latch Off |
Features | Package | |
| LT4256-1 | Latch Off | UV | SO-8 |
| LT4256-2 | Retry | UV | SO-8 |
| LT4256-3 | Latch Off or Retry | UV/OV, Open Circuit Detect | SSOP-16 |
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 |
|---|---|---|---|---|---|
| LT4256-3CGN#PBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT4256-3CGN#TRPBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT4256-3IGN#PBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT4256-3IGN#TRPBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | 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 | |
|---|---|---|---|---|---|---|
| LT4256-3CGN#PBF | SSOP-16 | C | $2.95 | $2.10 | Yes | |
| LT4256-3CGN#TRPBF | SSOP-16 | C | $2.16 | Yes | ||
| LT4256-3IGN#PBF | SSOP-16 | I | $3.48 | $2.45 | Yes | |
| LT4256-3IGN#TRPBF | SSOP-16 | I | $2.51 | 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.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC684A | LT4256-3 Positive Voltage Hot Swap Controller | $75.00 | |
| Buy Now | |||
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 | |
|---|---|---|---|---|---|---|
| LT4256-3IGN#PBF | SSOP-16 | I | $3.48 | $2.45 | Yes | |
| LT4256-3IGN#TRPBF | SSOP-16 | I | $2.51 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Hot Board Insertion
- Electronic Circuit Breaker/Power Bussing
- Industrial High Side Switch/Circuit Breaker
- 24V/48V Industrial/Alarm Systems
- Ideally Suited for 12V, 24V and 48V Distributed Power Systems
- 48V Telecom Systems
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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:
LT4256-1
LT4256-2
LT4256-3
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.
