LT1941 - Triple Monolithic Switching Regulator

Features

  • Click Here For LT1941 Evaluation Kit
  • Wide Input Range: 3.5V to 25V
  • Three Switching Regulators with Internal Power Switches: 3A Step-Down, 2A Step-Down, 1.5A Inverting/Boost
  • Antiphase Switching Reduces Ripple
  • Independent Shutdown/Soft-Start Pins
  • Independent Power Good Indicators Ease Supply Sequencing
  • Input Voltage Power Good Indicators Monitor Input Supply
  • Uses Small Inductors and Ceramic Capacitors
  • Constant 1.1MHz Switching Frequency
  • Thermally Enhanced 28-Lead TSSOP Package

Typical Application

LT1941
LT1941
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Description

The LT1941 is a triple current mode DC/DC converter with internal power switches. Two of the regulators are step-down converters with 3A and 2A power switches. The third regulator can be configured as a boost, inverter or SEPIC converter and has a 1.5A power switch. All three converters are synchronized to a 1.1MHz oscillator. The two step-down converters run with opposite phase, reducing input ripple current. The output voltages are set with external resistor dividers and each regulator has independent shutdown and soft-start circuits. Each regulator generates a power good signal when its output is in regulation, easing power supply sequencing and interfacing with microcontrollers and DSPs.

The high switching frequency offers several advantages by permitting the use of small inductors and ceramic capacitors, leading to a very small triple output solution. The constant switching frequency, combined with low impedance ceramic capacitors, result in low, predictable output ripple. With its wide input voltage range of 3.5V to 25V, the LT1941 regulates a broad array of power sources from 4-cell batteries and 5V logic rails to unregulated wall transformers, lead acid batteries and distributed-power supplies.

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Packaging

TSSOP-28

LT1941
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Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT1941EFE TSSOP 28 E $7.50 $5.25 View
LT1941EFE#PBF TSSOP 28 E $7.50 $5.25 View
LT1941EFE#TR TSSOP 28 E   $5.37 View
LT1941EFE#TRPBF TSSOP 28 E   $5.37 View
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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.

Evaluation Kits

Part Number Description Price
DC621A LT1941EFE | 1.1MHz Triple Output DC/DC Converter, Vin = 4.7V to 14V, Vout1 = 1.8V @ 2.4A, Vout2 = 3.3V @ 1.4A, Vout3 = -12V @ 240mA/550mA $150.00
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Applications

  • Cable Modems
  • DSL Modems
  • Distributed Power Regulation
  • Wall Transformer Regulation
  • Disk Drives
  • DSP Power
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Simulate

LTSpice / SwitcherCAD III is a powerful FREE circuit simulator and schematic capture program, providing macro models for 80% of Linear Technology's switching regulators, over 200 op amp models, as well as resistors, transistors and MOSFET models.

  • Step 1. If you do not already have a copy of LTSpice, click here to download and install LTSpice / SwitcherCAD III

  • Step 2. Once LTSpice is installed, click here for a ready to run  demonstration circuit of the LT1941.

  • Step 3. If LTspice / SwitcherCAD III does not automatically open after clicking the above link, 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 demonstartion circuit by selecting "Open" from the "File" menu.
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