LT3641 - Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer
- High Voltage Buck Regulator:
4V to 42V Operating Range
1.3A Output Current
- Input Transient Protection to 55V
- Low Voltage Synchronous Buck Regulator:
2.5V to 5.5V Input Voltage Range
1.1A Output Current
- Synchronizable, Adjustable 350kHz to 2.5MHz Switching Frequency
- Programmable Power-On Reset Timer
- Programmable Window Mode Watchdog Timer
- Typical Quiescent Current: 290μA
- Short-Circuit Robust
- Programmable Soft-Start
- Low Shutdown Current: IQ < 1μA
- Thermal Shutdown
- Available in Thermally Enhanced 28-Lead (4mm × 5mm) QFN and 28-Lead TSSOP Packages
The LT®3641 is a dual channel, current mode monolithic buck switching regulator with a power-on reset and a watchdog timer. Both regulators are synchronized to a single oscillator with an adjustable frequency (350kHz to 2.5MHz). At light loads, both regulators operate in low ripple Burst Mode® to maintain high effi ciency and low output ripple.
The high voltage channel is a nonsynchronous buck with an internal 2.4A top switch that operates from an input of 4V to 42V and input transient protection to 55V. The low voltage channel operates from an input of 2.5V to 5.5V. Internal synchronous power switches provide high effi ciency without the need of external Schottky diode. Both channels have cycle-by-cycle current limit, providing protection against shorted outputs.
The power-on reset and watchdog timeout periods are both adjustable using external capacitors. The window mode watchdog timer fl ags when the μP pulses group too close together or too far apart.
The LT3641 is available in a 28-pin 4mm × 5mm QFN package and 28-pin TSSOP package. Both packages have an exposed pad for low thermal resistance.
PackagingFor complete and up to date package information and drawings, please refer to our packaging page
4x5 QFN-28, TSSOP-28
- Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
- 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||Pins||Temp||Price (1-99)||Price (1k)*||RoHS Data|
|Buy Now • Request Samples|
Demo BoardsLinear 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.
|DC1727A||LT3641EFE Demo Board I Power-On Reset and Watchdog Timer, 7V ≤ VIN ≤ 42V (55V Transients), Vout1 = 5V @ 1A, Vout2 = 1.8V @ 0.8A||$125.00|
- Industrial Power Supplies
- Automotive Electronic Control Units
People Who Viewed This Product Also Viewed
- LT3988 - Dual 60V Monolithic 1A Step-Down Switching Regulator
- LT8610 - 42V, 2.5A Synchronous Step-Down Regulator with 2.5μA Quiescent Current
- LTC3115-1 - 40V, 2A Synchronous Buck-Boost DC/DC Converter
- LT3640 - Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer
- LT3508 - Dual Monolithic 1.4A Step-Down Switching Regulator
- LTC3646/LTC3646-1 - 40V, 1A Synchronous Step-Down Converter
- LTC3630 - High Efficiency, 65V 500mA Synchronous Step-Down Converter
- LT8705 - 80V VIN and VOUT Synchronous 4-Switch Buck- Boost DC/DC Controller
- LTC4364 - Surge Stopper with Ideal Diode
- LT3080 - Adjustable 1.1A Single Resistor Low Dropout Regulator
Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.
LTspice® IV 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 IV
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 IV
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice IV 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: