LINEAR TECHNOLOGY LT1640AL LT1640AH Negative Voltage Hot Swap Controller Data Sheet
Summary
The LT1640AL/LT1640AH is a critical 8-pin negative voltage hot swap controller for reliable operation in live -48V backplane systems. Engineered to ensure safe board insertion and removal across an operational range of –10V to –80V, this product incorporates advanced power protection features. The manual details key functions including programmable inrush current limiting, overvoltage/undervoltage lockout, and Power Good control output, making it essential for designing robust Central Office Switching or Distributed Power Systems that require precision power management.
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LT1640AL/LT1640AH Negative Voltage Hot Swap Controller
FEATURES DESCRIPTIO Allows Safe Board Insertion and Removal The LT®1640AL/LT1640AH are 8-pin, negative voltage from a Live –48V Backplane Hot Swap TM controllers that allow a board to be safely Operates from –10V to –80V inserted and removed from a live backplane. Inrush cur- Programmable Inrush Current rent is limited to a programmable value by controlling the Allows 50m A of Reverse Drain Pin Current gate voltage of an external N-channel pass transistor. The
Programmable Electronic Circuit Breaker pass transistor is turned off if the input voltage is less than Programmable Overvoltage Protection the programmable undervoltage threshold or greater than Programmable Undervoltage Lockout the overvoltage threshold. A programmable electronic Power Good Control Output circuit breaker protects the system against shorts. The PWRGD (LT1640AL) or PWRGD (LT1640AH) signal can be used to directly enable a power module. The LT1640AL
APPLICATIO S
is designed for modules with a low enable input and the LT1640AH for modules with a high enable input.
Central Office Switching –48V Distributed Power Systems The LT1640AL/LT1640AH are available in 8-pin PDIP and Negative Power Supply Control SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO (SHORT PIN)
Input Inrush Current
1% CONTACT BOUNCE
UV = 37V UV
9.09k LT1640AL PWRGD
OV = 71V OV
VEE SENSE GATE DRAIN
Q1 IRF530 ON/OFF
VIN VOUT 5V
* DIODES INC. SMAT70A SENSE+
† THESE COMPONENTS ARE APPLICATION C3 C4 C5 0.1µF 100µF TRIM 100µF
SPECIFIC AND MUST BE SELECTED BASED
UPON OPERATING CONDITIONS AND DESIRED SENSE– PERFORMANCE. SEE APPLICATIONS –VIN
INFORMATION.
1640A TA01
LUCENT JW050A1-E
Page Summary Contents For LINEAR TECHNOLOGY LT1640AL LT1640AH Negative Voltage Hot Swap Controller Data Sheet
Manual Details
| Brand | Linear |
|---|---|
| Pages | 16 |
| File Size | 316.25 KB |
| Published | June 02, 2026 |
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Frequently Asked Questions
What is the operating manual voltage range for the LT1640 series?
It operates from –10V to –80V.
How do I limit inrush current when using this controller?
Inrush current can be limited to a programmable value by controlling a resistor (R5).
What happens if the input voltage drops too low or goes too high?
The device has programmable undervoltage and overvoltage protection thresholds.
Which package options are available for the LT1640AL/LT1640AH?
They are available in 8-pin PDIP and 8-lead plastic SO packages.
What is the maximum junction temperature rating?
The maximum junction temperature is 125°C.