LT4250 - Negative 48V Hot Swap Controller
Datasheet 
DocumentationDatasheet
Design Note
Reliability Data
Product Selector Card
LT Journal
cad_symbol
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
,N-8,SO-8
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LT4250HCN8#PBF | PDIP | 8 | C | $2.75 | $2.30 |
| LT4250HCS8#PBF | SO | 8 | C | $2.85 | $2.35 |
| LT4250HCS8#TRPBF | SO | 8 | C | $2.41 | |
| LT4250HIN8#PBF | PDIP | 8 | I | $3.10 | $2.60 |
| LT4250HIS8#PBF | SO | 8 | I | $3.20 | $2.65 |
| LT4250HIS8#TRPBF | SO | 8 | I | $2.71 | |
| LT4250LCN8#PBF | PDIP | 8 | C | $2.75 | $2.30 |
| LT4250LCS8#PBF | SO | 8 | C | $2.85 | $2.35 |
| LT4250LCS8#TRPBF | SO | 8 | C | $2.41 | |
| LT4250LIN8#PBF | PDIP | 8 | I | $3.10 | $2.60 |
| LT4250LIS8#PBF | SO | 8 | I | $3.20 | $2.65 |
| LT4250LIS8#TRPBF | SO | 8 | I | $2.71 | |
| LT4250HCN8 | PDIP | 8 | C | $5.50 | $4.60 |
| LT4250HCS8 | SO | 8 | C | $5.70 | $4.70 |
| LT4250HCS8#TR | SO | 8 | C | $4.82 | |
| LT4250HIN8 | PDIP | 8 | I | $6.20 | $5.20 |
| LT4250HIS8 | SO | 8 | I | $6.40 | $5.30 |
| LT4250HIS8#TR | SO | 8 | I | $5.42 | |
| LT4250LCN8 | PDIP | 8 | C | $5.50 | $4.60 |
| LT4250LCS8 | SO | 8 | C | $5.70 | $4.70 |
| LT4250LCS8#TR | SO | 8 | C | $4.82 | |
| LT4250LIN8 | PDIP | 8 | I | $6.20 | $5.20 |
| LT4250LIS8 | SO | 8 | I | $6.40 | $5.30 |
| LT4250LIS8#TR | SO | 8 | I | $5.42 |
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 |