LT4250 - Negative 48V Hot Swap Controller
Features
- Allows Safe Board Insertion and Removal from a Live –48V Backplane
- Circuit Breaker Immunity to Voltage Steps and Current Spikes
- Programmable Inrush and Short-Circuit Current Limits
- Pin Compatible with LT1640L/LT1640H
- Operates from –18V to –80V
- Programmable Overvoltage Protection
- Programmable Undervoltage Lockout
- Power Good Control Output
- Bell-Core Compatible ON/OFF Threshold
Typical Application
Description
The LT4250L/LT4250H are 8-pin, negative 48V Hot Swap controllers that allow a board to be safely inserted and removed from a live backplane. Inrush current is limited to a programmable value by controlling the gate voltage of an external N-channel pass transistor. The pass transistor is turned off if the input voltage is less than the programmable undervoltage threshold or greater than the overvoltage threshold. A programmable current limit protects the system against shorts. After a 500μs timeout the current limit activates the electronic circuit breaker. The PWRGD (LT4250L) or PWRGD (LT4250H) signal can be used to directly enable a power module. The LT4250L is designed for modules with a low enable input and the LT4250H for modules with a high enable input.The LT4250L/LT4250H are available in 8-pin PDIP and SO packages
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 |
|---|---|---|---|---|---|
| LT4250HCN8#PBF | N-8 | N | C | 05-08-1510 (N8) | Yes |
| LT4250HCS8#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT4250HCS8#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT4250HIN8#PBF | N-8 | N | I | 05-08-1510 (N8) | Yes |
| LT4250HIS8#PBF | SO-8 | S8 | I | 05-08-1610 (S8) | Yes |
| LT4250HIS8#TRPBF | SO-8 | S8 | I | 05-08-1610 (S8) | Yes |
| LT4250LCN8#PBF | N-8 | N | C | 05-08-1510 (N8) | Yes |
| LT4250LCS8#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT4250LCS8#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT4250LIN8#PBF | N-8 | N | I | 05-08-1510 (N8) | Yes |
| LT4250LIS8#PBF | SO-8 | S8 | I | 05-08-1610 (S8) | Yes |
| LT4250LIS8#TRPBF | SO-8 | S8 | I | 05-08-1610 (S8) | 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 | |
|---|---|---|---|---|---|---|
| LT4250HCN8#PBF | N-8 | C | $2.75 | $2.30 | Yes | |
| LT4250HCS8#PBF | SO-8 | C | $2.85 | $2.35 | Yes | |
| LT4250HCS8#TRPBF | SO-8 | C | $2.41 | Yes | ||
| LT4250HIN8#PBF | N-8 | I | $3.10 | $2.60 | Yes | |
| LT4250HIS8#PBF | SO-8 | I | $3.20 | $2.65 | Yes | |
| LT4250HIS8#TRPBF | SO-8 | I | $2.71 | Yes | ||
| LT4250LCN8#PBF | N-8 | C | $2.75 | $2.30 | Yes | |
| LT4250LCS8#PBF | SO-8 | C | $2.85 | $2.35 | Yes | |
| LT4250LCS8#TRPBF | SO-8 | C | $2.41 | Yes | ||
| LT4250LIN8#PBF | N-8 | I | $3.10 | $2.60 | Yes | |
| LT4250LIS8#PBF | SO-8 | I | $3.20 | $2.65 | Yes | |
| LT4250LIS8#TRPBF | SO-8 | I | $2.71 | 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 |
|---|---|---|---|
| DC429A | LT4250LCS8 | Negative Voltage Hot Swap Controller | $50.00 | |
| Buy Now | |||
Applications
- Central Office Switching
- –48V Distributed Power Systems
- Negative Power Supply Control
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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:
LT4250H
LT4250L
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.
