LINEAR TECHNOLOGY LT1640L LT1640H Specification User Guide
Summary
The LT1640L/LT1640H is an advanced Negative Voltage Hot Swap Controller designed for robust safety in high-reliability power systems. Enabling safe board insertion and removal from live backplanes operating between –10V and –80V, this device significantly enhances system protection. The companion manual provides comprehensive details on programmable features including inrush current limiting, overvoltage/undervoltage lockout, and short-circuit circuit protection. It is essential for engineers designing complex distributed power or central office switching modules utilizing negative voltages (-48V).
Page 1 Text Content
LT1640L/LT1640H Negative Voltage Hot Swap Controller
FEATURES DESCRIPTIO
Allows Safe Board Insertion and Removal The LT®1640L/LT1640H is an 8-pin, negative voltage Hot from a Live –48V Backplane Swap TM controller that allows a board to be safely inserted Operates from –10V to –80V and removed from a live backplane. Inrush current is Programmable Inrush Current limited to a programmable value by controlling the gate Programmable Electronic Circuit Breaker voltage of an external N-channel pass transistor. The pass
Programmable Overvoltage Protection transistor is turned off if the input voltage is less than the Programmable Undervoltage Lockout programmable undervoltage threshold or greater than the Power Good Control Output overvoltage threshold. A programmable electronic circuit breaker protects the system against shorts. The PWRGD (LT1640L) or PWRGD (LT1640H) signal can be used to
APPLICATIO
directly enable a power module. The LT1640L is designed for modules with a low enable input and the LT1640H for
Central Office Switching
modules with a high enable input.
–48V Distributed Power Systems Negative Power Supply Control The LT1640L/LT1640H is available in 8-pin PDIP and 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) GND GND
Input Inrush Current
INRUSH
R5† CURRENT
9.09k LT1640L PWRGD
1A/DIV
UV = 37V
VEE SENSE GATE DRAIN
GATE – VEE
OV = 71V 10V/DIV
150n F 10Ω C2† R1† 18k DRAIN 25V 5% 3.3n F 0.02Ω 5%
100V 50V/DIV
–48V VEE
50V/DIV
IRF530 ON/OFF
VIN VOUT 5V
CONTACT
* DIODES INC. SMAT70A SENSE+ BOUNCE
† THESE COMPONENTS ARE APPLICATION C3 C4 C5 0.1µF 100µF TRIM 100µF
SPECIFIC AND MUST BE SELECTED BASED 1640 F06b
100V 100V 16V 5ms/DIV
UPON OPERATING CONDITIONS AND DESIRED SENSE– PERFORMANCE. SEE APPLICATIONS –VIN
INFORMATION.
1640 TA01
LUCENT JW050A1-E
1640lhfb
Page Summary Contents For LINEAR TECHNOLOGY LT1640L LT1640H Specification User Guide
Manual Details
| Brand | Linear |
|---|---|
| Pages | 16 |
| File Size | 187.76 KB |
| Published | June 22, 2026 |
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Frequently Asked Questions
What is the operating voltage range for the LT1640 controllers?
The controller operates from –10V to –80V and handles a -48V backplane.
How does the module protect against short circuits?
A programmable electronic circuit breaker protects the system against shorts.
Can this controller be used in different equipment environments?
The product is available in both 8-pin PDIP and SO packages, suitable for various applications.
What design features allow safe component insertion/removal?
It provides Hot Swap capabilities, allowing safe board insertion and removal from a live backplane.