LTC7890
Info : RECOMMENDED FOR NEW DESIGNS
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LTC7890

Low IQ, Dual, 2-Phase Synchronous Step-Down Controller for GaN FETs

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Info : RECOMMENDED FOR NEW DESIGNS tooltip
Info : RECOMMENDED FOR NEW DESIGNS tooltip
Part Details
Part Models 2
1ku List Price Starting From $3.37
Features
  • GaN drive technology fully optimized for GaN FETs
  • Wide VIN range: 4 V to 100 V
  • Wide output voltage range: 0.8 V ≤ VOUT ≤ 60 V
  • No catch, clamp, or bootstrap diodes needed
  • Internal smart bootstrap switches prevent overcharging of high-side driver supplies
  • Internally optimized, smart near zero dead times or resistor adjustable dead times
  • Split output gate drivers for adjustable turn on and turn off driver strengths
  • Accurate adjustable driver voltage and UVLO
  • Low IQ: 5 μA (48 VIN to 5 VOUT, Ch 1 On)
  • Programmable frequency (100 kHz to 3 MHz)
  • Synchronizable frequency (100 kHz to 3 MHz)
  • Spread spectrum frequency modulation
  • 40-lead (6 mm × 6 mm), side wettable, QFN package
Additional Details
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The LTC7890 is a high performance, dual step-down, dc-to-dc switching regulator controller that drives all N-channel synchronous gallium nitride (GaN) field effect transistor (FET) power stages from input voltages up to 100 V. The LTC7890 solves many of the challenges traditionally faced when using GaN FETs. The LTC7890 simplifies the application design while requiring no protection diodes and no other additional external components compared to a silicon metal-oxide semiconductor field effect transistor (MOSFET) solution.

The internal smart bootstrap switches prevent overcharging of the BOOSTx pin to the SWx pin high-side driver supplies during dead times, protecting the gate of the top GaN FET. The LTC7890 internally optimizes the gate driver timing on both switching edges to achieve smart near zero dead times, significantly improving efficiency and allowing for high frequency operation, even at high input voltages. Alternatively, the user can adjust the dead times with external resistors for margin or to tailor the application.

The gate drive voltage of the LTC7890 can be precisely adjusted from 4 V to 5.5 V to optimize performance and to allow the use of different GaN FETs or even logic level MOSFETs.

APPLICATIONS

  • Industrial power systems
  • Military avionics and medical systems
  • Telecommunications power systems
Part Models 2
1ku List Price Starting From $3.37

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Documentation

Documentation

Video

Part Model Pin/Package Drawing Documentation CAD Symbols, Footprints, and 3D Models
LTC7890RUJM#PBF
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Software & Part Ecosystem

Software & Part Ecosystem

Evaluation Kit

Evaluation Kits 3

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EVAL-LTC7890-AZ

High Frequency, Dual Output, Step-Down Supply with EPC GaN FETs

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EVAL-LTC7890-AZ

High Frequency, Dual Output, Step-Down Supply with EPC GaN FETs

High Frequency, Dual Output, Step-Down Supply with EPC GaN FETs

Product Detail

Evaluation circuit EVAL-LTC7890-AZ is a dual output synchronous step-down converter that drives all N-channel gallium nitride (GaN) field effect transistors (FETs). The EVAL-LTC7890-AZ evaluation board features EPC2218 100V FETs from EPC.

EVAL-LTC7890-AZ features the LTC®7890: a low quiescent current high frequency (programmable fixed frequency from 100kHz up to 3MHz) dual step-down DC/DC synchronous controller, with a dedicated driver feature for GaN FETs housed in a small 6mm × 6mm QFN package.

The EVAL-LTC7890-AZ operates over an input voltage range from 14V to 72V, while the LTC7890 can operate up to 100V. The EVAL-LTC7890-AZ evaluation circuit produces two outputs: 5V and 12V with up to 20A on each output. EVAL-LTC7890-AZ is configured with sense resistors for current sensing. A mode selector allows the EVAL-LTC7890-AZ to operate in forced continuous operation, pulse-skipping or Burst Mode® operation during light loads. The EXTVCC pin permits the LTC7890 to be powered from the output of the switching regulator or other available source, reducing power dissipation, and improving efficiency. Refer to the LTC7890 data sheet for a complete description of the part operation and application information.

The performance summary table summarizes the performance of the evaluation circuit at room temperature. The evaluation circuit can be easily modified for different applications, including 2-phase single output. The LTC7890 is housed in a 40-lead (6mm × 6mm), side wettable, QFN package. Refer to the data sheet in conjunction with this EVAL-LTC7890-AZ evaluation circuit user guide.

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DC2938A

LTC7890 | High Frequency, Dual Output, Synchronous Buck Converter Using GaN FETs

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DC2938A

LTC7890 | High Frequency, Dual Output, Synchronous Buck Converter Using GaN FETs

LTC7890 | High Frequency, Dual Output, Synchronous Buck Converter Using GaN FETs

Product Detail

Demonstration circuit 2938A is a dual output nonisolated synchronous step-down converter that drives all N-channel gallium nitride (GaN) FET power stages. DC2938A features the LTC®7890, a low quiescent current high frequency (programmable fixed frequency from 100kHz up to 3MHz) dual step-down DC/DC synchronous controller, with dedicated driver feature for GaN FET housed in a small 6mm × 6mm QFN package.

The DC2938A operates over an input voltage range from 30V to 72V, while the LTC7890 can operate up to 100V. The DC2938A demo board produces two outputs: 5V and 12V with up to 20A output, respectively. DC2938A is configured with a sense resistor for current sensing. A mode selector allows the DC2938A to operate in forced continuous operation, pulse-skipping or Burst Mode® operation during light loads. DTCA and DTCB selector provides easy adjustment of the dead time to improve efficiency or to tailor the application. DRVSET and DRVUV selector offers option to choose drive voltage from 4V to 5.5V to optimize performance.

The EXTVCC pin permits the LTC7890 to be powered from the output of the switching regulator or other available source, reducing power dissipation, and improving efficiency. Please refer to the LTC7890 data sheet for a complete description of the part operation and application information.

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EVAL-LTC7890-BZ

High Frequency, Dual Output, Step-Down Supply with Si FETs

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EVAL-LTC7890-BZ

High Frequency, Dual Output, Step-Down Supply with Si FETs

High Frequency, Dual Output, Step-Down Supply with Si FETs

Product Detail

Evaluation circuit EVAL-LTC7890-BZ is a dual output synchronous step-down converter that drives N-channel silicon (Si) field effect transistors (FETs). The EVAL-LTC7890-BZ evaluation board features 100V logic-level Si FETs.

EVAL-LTC7890-BZ features the LTC®7890: a low quiescent current, high frequency (programmable fixed frequency from 100kHz up to 3MHz), dual step-down DC/DC synchronous controller, with a dedicated driver feature for GaN FETs, which can also be used to drive logic-level silicon FETs. To evaluate the LTC7890 with GaN FETs, refer to the EVAL-LTC7890-AZ evaluation board, which does 12VOUT at 20A and 5VOUT at 20A.

The EVAL-LTC7890-BZ operates over an input voltage range from 16V to 72V, while the LTC7890 can operate up to 100V. The EVAL-LTC7890-BZ evaluation circuit produces two outputs: 5V and 12V, with up to 10A on each output. EVAL-LTC7890-BZ is configured with sense resistors for current sensing. A mode selector allows the EVAL-LTC7890-BZ to operate in forced continuous operation, pulse-skipping or Burst Mode® operation during light loads. The EXTVCC pin permits the LTC7890 to be powered from the output of the switching regulator or other available source, reducing power dissipation, and improving efficiency. Refer to the LTC7890 data sheet for a complete description of the part operation and application information.

The performance summary table summarizes the performance of the evaluation circuit at room temperature. The evaluation circuit can be easily modified for different applications, including 2-phase single output. The LTC7890 is housed in a 40-lead (6mm × 6mm), side wettable, QFN package. Refer to the data sheet in conjunction with this EVAL-LTC7890-BZ evaluation circuit user guide.

Design files for this circuit board are available at www.analog.com.

Tools & Simulations

Tools & Simulations 1

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, 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.

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