DC2494A: 5V @ 2A, 6.5 ~ 40V in, Step Down

Demonstration circuit 2494A is a 40V, 2A step-down µModule® regulator featuring the LTM®8063. The demo board is designed for 5V output from a 6.5V to 40V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The user adjustable features of the LTM8063 such as output voltage, switching frequency, soft-start, and power good can be changed on DC2494A simply by modifying the appropriate resistors and/or capacitors.

The LTM8063 can be programmed to different operation modes. The SYNC pin on the demo board is grounded by default for low ripple Burst Mode® operation. Moving JP1 to PULSE SKIPPING position changes the operation mode to pulse-skipping operation. To synchronous to an external clock, move JP1 to SYNC and apply the external clock to the SYNC turret. Once JP1 is on SPREAD SPECTRUM position, an external DC source can be applied to the SYNC pin to enable low EMI spread spectrum operation. This DC source can also be generated from Vout with appropriate voltage divider if VOUT is 2.9V or higher. See the Quick Start Procedure section for more details.

Chart 1 shows the efficiency of the circuit under different input voltages in Burst Mode operation. The rated maximum load current is 2A, while derating is necessary for certain input voltage and thermal conditions. Chart 2 shows the LTM8063 thermal performance on DC2494A demo board.

The demo board has an EMI filter installed. An inductor L1, which is shorted on the board by default, can be added in the EMI filter to further reduce the conducted emission. The LTM8063 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for DC2494A.