Analog Devices Inc. LT3840 Demo Board DC1909A

Analog Devices Inc. LT3840 Demo Board DC1909A is an evaluation board featuring a 150kHz, 60V current mode DC-DC step-down converter example circuit based on the LT3840 Wide Input Range Synchronous Regulator Controller with Accurate Current Limit. The LT3840 Demo Board DC1909A operates from a VIN range of 4.5V to 60V, survives an 80V transient, and outputs 3.3V at 20A (66W). An integrated buck-boost switching regulator generates a 7.5V bias supply voltage for MOSFET gate drive and IC power to increase the overall efficiency by reducing the power loss. 

The soft-start feature of the DC1909A controls the output voltage slew rate at start-up, reducing current surges and voltage overshoots. Operation Mode Jumpers on the Demonstration Circuit Board allow Burst Mode®, Discontinuous Current Mode, and Continuous Current Mode to be selected. Both Burst Mode operation and Discontinuous Current Mode increase the efficiency at light loads. Continuous Current Mode will maintain a constant switching frequency regardless of the load current.

The average current control loop regulates the maximum output current of the switching regulator. An optional Low Dropout (LDO) circuit is provided on the bottom side of the board for programming the LT3840 current limit set point.


  • Input Supply Range (VIN): 4.5V to 60V
  • Output Voltage Range (VOUT): 3.168V to 3.432V, 3.3V typical
  • Output Current Range (IOUT): 18.8A to 21.2A, 20A typical
  • Switching Frequency (fSW): 150kHz
  • Output Ripple (VOUT(P-P)): 50mV
  • Output Regulation ((VREG): 0.15%

Measurement Equipment Setup

Mechanical Drawing - Analog Devices Inc. LT3840 Demo Board DC1909A
Publicado: 2019-06-24 | Actualizado: 2022-03-11