industry news
Subscribe Now

36V Monolithic 1A Push-Pull DC/DC Transformer Driver with Programmable Duty Cycle Control

MILPITAS, CA – September 22, 2014 – Linear Technology Corporation announces the LT3999, a monolithic push-pull isolated DC/DC transformer driver with two 1A current limited power switches. The LT3999 operates over an input voltage range of 2.7V to 36V, is targeted for power levels up to 15W and can produce a wide range of output voltages. This makes it well suited for automotive, industrial, medical and military applications.

The programmable duty cycle and turns ratio of the transformer sets the output voltage. Several off-the-shelf transformers shown in the data sheet simplify the design. The switching frequency is adjustable from 50kHz to 1MHz and can be synchronized to an external clock. The LT3999 input operating voltage range is set with the precise undervoltage and overvoltage lockouts. The supply current is reduced to less than 1µA during shutdown. A user-defined RC time constant provides an adjustable soft-start capability by limiting the inrush current at start-up and an onboard cross-conduction prevention circuit increases reliability.

The LT3999 is available in thermally enhanced MSOP-10 and 3mm x 3mm DFN-10 packages. The LT3999 E- and I-grade versions operate from a -40°C to 125°C junction temperature. The LT3999 H grade is guaranteed to operate from a -40°C to 150°C operating junction temperature. The LT3999 MP grade is guaranteed to operate from -55°C to 150°C operating junction temperature. Devices are in stock, and the 1,000-piece price starts at $2.75 each for the E-grade. For more information, visit www.linear.com/product/LT3999

Summary of Features: LT3999

  • Wide VIN Range: 2.7V to 36V
  • Dual 1A Switches
  • Programmable Switching Frequency: 50kHz to 1MHz
  • Synchronizable to an External Clock up to 1MHz
  • Duty Cycle Control for Output Voltage Regulation
  • Low Noise Topology
  • Programmable Input Over & Undervoltage Lockout
  • Cross-Conduction Prevention Circuitry
  • Extended & Industrial Grades: -40°C to 125°C Operating Junction Temp
  • Automotive Temp Grade: -40°C to 150°C Operating Junction Temp
  • Military Temp Grade: -55°C to 150°C Operating Junction Temp

The USA list pricing shown is for budgetary use only. International prices may differ due to local duties, taxes, fees and exchange rates.

About Linear Technology

Linear Technology Corporation, a member of the S&P 500, has been designing, manufacturing and marketing a broad line of high performance analog integrated circuits for major companies worldwide for over three decades. The Company’s products provide an essential bridge between our analog world and the digital electronics in communications, networking, industrial, automotive, computer, medical, instrumentation, consumer, and military and aerospace systems. Linear Technology produces power management, data conversion, signal conditioning, RF and interface ICs, µModule® subsystems, and wireless sensor network products. For more information, visitwww.linear.com.

Leave a Reply

featured blogs
Apr 24, 2026
A thought experiment in curiosity, confusion, and cosmic consequences....

featured paper

Quickly and accurately identify inter-domain leakage issues in IC designs

Sponsored by Siemens Digital Industries Software

Power domain leakage is a major IC reliability issue, often missed by traditional tools. This white paper describes challenges of identifying leakage, types of false results, and presents Siemens EDA’s Insight Analyzer. The tool proactively finds true leakage paths, filters out false positives, and helps circuit designers quickly fix risks—enabling more robust, reliable chip designs. With detailed, context-aware analysis, designers save time and improve silicon quality.

Click to read more

featured chalk talk

Nexperia GaN Power Proliferating in All Things Motor Control/Drive
Sponsored by Mouser Electronics and Nexperia
In this episode of Chalk Talk, Art Gonsky from Nexperia and Amelia Dalton discuss the biggest challenges of electric motors and controllers and how GaN power solutions can help solve these issues. They  also investigate how silicon, silicon carbide and GaN power solutions compare and how Nexperia and NXP technologies can get your next motor control design up and running in no time!     
Mar 25, 2026
29,507 views