Analog Devices Inc. LT3942 Demo Board DC3103A

Analog Devices Inc. LT3942 Demo Board DC3103A is an evaluation platform for the LT3942 Synchronous Buck-Boost Converter and LED driver. The LT3942 can regulate the LED string current up to 34V with input voltages above, below, or equal to the output voltage. The proprietary peak-buck peak-boost current mode control scheme allows adjustable and synchronizable 300kHz to 2MHz fixed-frequency operation, or internal 25% triangle spread-spectrum operation for low EMI. With 3V to 36V input, 0V to 36V output, and seamless low-noise transitions between operation regions, LT3942 is ideal for LED driver applications in automotive, industrial, and battery-powered systems.

The Analog Devices Inc. DC3103A Demonstration Board features a pre-installed LT3942 in a QFN-28 package. The Demonstration Board provides an example application circuit with an output voltage set to 12V with the capability of delivering up to 1A when the input voltage is between 7V and 36V. The Demonstration Board continues operating with an input voltage as low as 3V with reduced output power capability. DC3103A is pre-configured for a 2MHz switching frequency with Spread Spectrum Frequency Modulation (SSFM) disabled. When enabled, SSFM adjusts the switching frequency of the LT3942 between 2MHz and 2.5MHz for improved EMI performance.

The board is designed with ceramic capacitors placed near the PVIN and PVOUT pins to form a compact high-frequency hot loop. SMD pads are available to install an optional ferrite bead EMI filter on both the input and output of DC3103A. These filters, combined with proper board layout and SSFM, effectively reduce both radiated and conducted EMI.


  • Pre-installed LT3942 in a QFN-28 package
  • 3V to 36V input voltage range (VIN)
  • Switching frequency (fSW)
    • SSFM off: 2MHz 
    • SSFM on: 2MHz to 2.5MHz
  • 12V output voltage (VOUT)
  • 89% typical efficiency
  • User-selectable modes
  • Test points for key signals

Test Setup

Analog Devices Inc. LT3942 Demo Board DC3103A
Published: 2021-07-13 | Updated: 2022-03-11