LTC4253A-ADJ - -48V Hot Swap Controller with Sequencer
Features
- Obsolete - Contact Linear Technology for Potential Replacement
- Allows Safe Board Insertion and Removal from a Live – 48V Backplane
- Floating Topology Permits Very High Voltage Operation
- Adjustable Analog Current Limit with Breaker Timer
- Fast Response Time Limits Peak Fault Current
- Adjustable Undervoltage/Overvoltage Protection with ±1% Threshold Accuracy
- Three Sequenced Power Good Outputs
- Adjustable Soft-Start Current Limit
- Adjustable Timer with Drain Voltage Accelerated Response
- Latchoff After Fault
- Available in 20-Pin SSOP and 20-Pin (4mm × 4mm) QFN Packages
Typical Application
Description
The LTC4253A-ADJ negative voltage Hot Swap controller allows a board to be safely inserted and removed from a live backplane. Output current is controlled by three stages of current-limiting: a timed circuit breaker, active current limiting and a fast feedforward path that limits peak current under worst-case catastrophic fault conditions. The LTC4253A-ADJ latches off after a circuit fault.
Undervoltage and overvoltage detectors with adjustable thresholds and hystereses disconnect the load whenever the input supply exceeds the desired operating range. The LTC4253A-ADJ's supply input is shunt-regulated, allowing safe operation with very high supply voltages. A multifunction timer delays initial start-up and controls the circuit breaker's response time. The circuit breaker's response time can be accelerated by sensing excessive MOSFET drain voltage. An adjustable soft-start circuit controls MOSFET inrush current at start-up.
Three power good outputs can be sequenced to enable external power modules at start-up or disable them if the circuit breaker trips. The LTC4253A-ADJ is available in 20-pin SSOP and 20-pin (4mm × 4mm) QFN packages.
| Notes | |
| LTC4253 | |
| LTC4253A | Recommend LTC4253B for new designs |
| LTC4253A-ADJ | Recommend LTC4253B for new designs |
| LTC4253B |
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
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
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
Applications
- -48V Distributed Power Systems
- Negative Power Supply Control
- Central Office Switching
- High Availability Servers
- Disk Arrays
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Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
- LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
- LTpowerCAD - A complete power supply selection, synthesis and design tool
- LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
- PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
- Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
- LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
- And More!
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.