DocumentationDatasheet
Design Note
Reliability Data
Product Selector Card
LT Journal
- August 2004 - Versatile 80V Hot Swap Controllers Drive Large MOSFETs; Improve Accuracy and Foldback Current Limiting
- Feb 2001 48V Hot Swap Circuit Blocks Reverse Battery Voltage
cad_symbol
Features
- Allows Safe Board Insertion and Removal from a Live Backplane
- Controls Supply Voltage from 9V to 80V
- Programmable Analog Foldback Current Limiting
- High Side Drive for an External N-Channel
- Automatic Retry Capability
- User Programmable Supply Voltage Power-Up Rate
- Undervoltage Lockout
- Overvoltage Protection
- Available in 8-Lead SO Package
Typical Application
Description
The LT1641 is an 8-pin Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. Using an external N-channel pass transistor, the board supply voltage can be ramped up at a programmable rate. A high side switch driver controls an N-channel gate for supply voltages ranging from 9V to 80V.
The chip features a programmable analog foldback current limit circuit. If the chip remains in current limit for more than a programmable time, the N-channel pass transistor turns off and is optionally set to automatically restart after a time-out delay.
The PWRGD output indicates when the output voltage, sensed by the FB pin, is within tolerance. The ON pin provides programmable undervoltage lockout.
The LT1641-1/LT1641-2 are recommended for new designs.
The LT1641 is available in the 8-lead SO package.
SO-8
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LT1641-1CS8#PBF | SO | 8 | C | $2.75 | $2.35 |
| LT1641-1CS8#TRPBF | SO | 8 | C | $2.41 | |
| LT1641-1IS8#PBF | SO | 8 | I | $3.00 | $2.60 |
| LT1641-1IS8#TRPBF | SO | 8 | I | $2.66 | |
| LT1641-2CS8#PBF | SO | 8 | C | $2.75 | $2.35 |
| LT1641-2CS8#TRPBF | SO | 8 | C | $2.41 | |
| LT1641-2IS8#PBF | SO | 8 | I | $3.00 | $2.60 |
| LT1641-2IS8#TRPBF | SO | 8 | I | $2.66 | |
| LT1641CS8#PBF | SO | 8 | C | $2.75 | $2.35 |
| LT1641CS8#TRPBF | SO | 8 | C | $2.41 | |
| LT1641IS8#PBF | SO | 8 | I | $3.00 | $2.60 |
| LT1641IS8#TRPBF | SO | 8 | I | $2.66 | |
| LT1641CS8 | SO | 8 | C | $5.50 | $4.70 |
| LT1641CS8#TR | SO | 8 | C | $4.82 | |
| LT1641IS8 | SO | 8 | I | $6.00 | $5.20 |
| LT1641IS8#TR | SO | 8 | I | $5.32 | |
| LT1641-1CS8 | SO | 8 | C | $5.50 | $4.70 |
| LT1641-1CS8#TR | SO | 8 | C | $4.82 | |
| LT1641-1IS8 | SO | 8 | I | $6.00 | $5.20 |
| LT1641-1IS8#TR | SO | 8 | I | $5.32 | |
| LT1641-2CS8 | SO | 8 | C | $5.50 | $4.70 |
| LT1641-2CS8#TR | SO | 8 | C | $4.82 | |
| LT1641-2IS8 | SO | 8 | I | $6.00 | $5.20 |
| LT1641-2IS8#TR | SO | 8 | I | $5.32 |
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.