DC1924A

Demonstration circuit 1924A is a high performance buckboost converter featuring the LT®8705 that can operate from input voltages above, below or equal to the output voltage. The demo board input range is 36V to 80V. The output is optimized for 48V at 5A, with the output current limit set at 7A. (The circuit will operate with lower input voltage than 36V if load current is reduced). The controller has integrated input current, input voltage, output current and output voltage regulators. The one regulator that wants to decrease current gets control over the compensation pin VC. The inductor current is controlled by the VC signal that is fed into a current comparator together with a ramp compensation signal. Additional circuitry may be needed depending on the application. Typical efficiency with 5A load is above 97% across a 36V to 72V input range using the supplied inductor. Lower core loss can be achieved by using a ferrite core inductor.

• Switching frequency of 200KHz
• Efficiency at DC input is 97.5% (VIN = 72V, VOUT = 48V, IOUT = 5A)

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party