LTC7138 - High Efficiency, 140V 400mA Step-Down Regulator

Features

  • Wide Operating Input Voltage Range: 4V to 140V
  • Internal Low Resistance Power MOSFET
  • No Compensation Required
  • Adjustable 100mA to 400mA Maximum Output Current
  • Low Dropout Operation: 100% Duty Cycle
  • Low Quiescent Current: 12μA
  • Wide Output Range: 0.8V to VIN
  • 0.8V ±1% Feedback Voltage Reference
  • Precise RUN Pin Threshold
  • Internal or External Soft-Start
  • Programmable 1.8V, 3.3V, 5V or Adjustable Output
  • Few External Components Required
  • Programmable Input Overvoltage Lockout
  • Thermally Enhanced High Voltage MSOP Package

Typical Application

LTC7138 Typical Application
LTC7138 Typical Application

Description

The LTC®7138 is a high efficiency step-down DC/DC regulator with internal power switch that draws only 12μA typical DC supply current while maintaining a regulated output voltage at no load.

The LTC7138 can supply up to 400mA load current and features a programmable peak current limit that provides a simple method for optimizing efficiency and for reducing output ripple and component size. The LTC7138’s combination of Burst Mode® operation, integrated power switch, low quiescent current, and programmable peak current limit provides high efficiency over a broad range of load currents.

With its wide input range of 4V to 140V and programmable overvoltage lockout, the LTC7138 is a robust regulator suited for regulating from a wide variety of power sources. Additionally, the LTC7138 includes a precise run threshold and soft-start feature to guarantee that the power system start-up is well-controlled in any environment. A feedback comparator output enables multiple LTC7138s to be connected in parallel for higher current applications.

The LTC7138 is available in a thermally enhanced high voltage-capable 16-lead MSE package with four missing pins.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC7138EMSE#PBF MS-16E MSE E 05-08-1871 Yes
LTC7138EMSE#TRPBF MS-16E MSE E 05-08-1871 Yes
LTC7138HMSE#PBF MS-16E MSE H 05-08-1871 Yes
LTC7138HMSE#TRPBF MS-16E MSE H 05-08-1871 Yes
LTC7138IMSE#PBF MS-16E MSE I 05-08-1871 Yes
LTC7138IMSE#TRPBF MS-16E MSE I 05-08-1871 Yes
LTC7138MPMSE#PBF MS-16E MSE MP 05-08-1871 Yes
LTC7138MPMSE#TRPBF MS-16E MSE MP 05-08-1871 Yes


LTC7138 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
LTC7138EMSE#PBF MS-16E E $5.43 $3.80 Yes
LTC7138EMSE#TRPBF MS-16E E $3.86 Yes
LTC7138HMSE#PBF MS-16E H $6.33 $4.43 Yes
LTC7138HMSE#TRPBF MS-16E H $4.49 Yes
LTC7138IMSE#PBF MS-16E I $5.97 $4.18 Yes
LTC7138IMSE#TRPBF MS-16E I $4.24 Yes
LTC7138MPMSE#PBF MS-16E MP $16.13 $11.29 Yes
LTC7138MPMSE#TRPBF MS-16E MP $11.35 Yes
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* 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
DC2172A LTC7138EMSE Demo Board | HV uPower Buck, 4V ≤ VIN ≤ 140V, Vout = 5V/3.3V/1.8V/Adj @ Up to 400mA $200.00
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Click here to view our complete list of demo boards

Applications

  • Industrial Control Supplies
  • Medical Devices
  • Distributed Power Systems
  • Portable Instruments
  • Battery-Operated Devices
  • Avionics
  • Automotive

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice IV:
LTC7138

Technical Support