LTC1921 - Dual -48V Supply and Fuse Monitor

Features

  • Withstands Transient Voltages Up to 200V/–200V
  • Requires No Precision External Components
  • Independently Monitors Two –48V Supplies for
  • – Undervoltage Faults: –38.5V ±1VMAX
    – Overvoltage Faults: –70V ±1.5VMAX
  • Accurately Detects Undervoltage Fault Recovery:
    –43V ±0.5VMAX
  • Monitors Two External Fuses
  • Operates from –10V to –80V
  • Tolerates DC Faults to –100V
  • Tolerates Accidental Supply Reversal to 100V
  • Small Footprint: 8-Lead MSOP Package
  • Specified from –40°C to 85°C
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LTC1921 Typical Application

Description

The LTC®1921 monitors two independent –48V supplies, including their fuses, and drives up to three optoisolators to indicate status, in accordance with standard backplane specifications. Requiring only three noncritical resistors and optoisolators, the LTC1921 replaces multiple voltage comparators, a voltage reference and several precision resistors.

The monitor features dual supply overvoltage and undervoltage detection circuits. The preset trip thresholds include overvoltage, undervoltage and undervoltage recovery that are guaranteed over temperature and meet or exceed common backplane specifications. Additional built-in circuitry detects the condition of supply fuses. Overvoltage and undervoltage detectors ignore fast supply transients, eliminating false detection. The LTC1921 operates from –10V to –80V with a typical power dissipation of less than 10mW.

The LTC1921 is available in 8-pin MSOP and SOIC 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
LTC1921CMS8#PBF MS-8 MS8 C 05-08-1660 Yes
LTC1921CMS8#TRPBF MS-8 MS8 C 05-08-1660 Yes
LTC1921CS8#PBF SO-8 S8 C 05-08-1610 (S8) Yes
LTC1921CS8#TRPBF SO-8 S8 C 05-08-1610 (S8) Yes
LTC1921IMS8#PBF MS-8 MS8 I 05-08-1660 Yes
LTC1921IMS8#TRPBF MS-8 MS8 I 05-08-1660 Yes
LTC1921IS8#PBF SO-8 S8 I 05-08-1610 (S8) Yes
LTC1921IS8#TRPBF SO-8 S8 I 05-08-1610 (S8) Yes


LTC1921 Package Drawing
LTC1921 Package Drawing

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
LTC1921CMS8#PBF MS-8 C $3.40 $2.50 Yes
LTC1921CMS8#TRPBF MS-8 C $2.56 Yes
LTC1921CS8#PBF SO-8 C $3.75 $2.65 Yes
LTC1921CS8#TRPBF SO-8 C $2.71 Yes
LTC1921IMS8#PBF MS-8 I $4.20 $3.15 Yes
LTC1921IMS8#TRPBF MS-8 I $3.21 Yes
LTC1921IS8#PBF SO-8 I $4.35 $3.30 Yes
LTC1921IS8#TRPBF SO-8 I $3.36 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

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
DC548A LTC1921CMS8 | Dual -48V Suppy and Fuse Monitor Contact Factory
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1921IMS8#PBF MS-8 I $4.20 $3.15 Yes
LTC1921IMS8#TRPBF MS-8 I $3.21 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Applications

  • Telecom Backplanes or Switch Cards
  • Networking Backplanes or Switch Cards
  • High Voltage Fuse Monitoring

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
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  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

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