DC2543A(2): 20A, 36 ~ 60V in, 2:1 Step-Down Charge Pump

Demonstration circuit 2543A is a high efficiency, high density, open loop charge pump (inductorless) DC/DC converter. This demo board is a voltage divider which achieves a 2:1 step-down ratio from an input voltage from 36V to 60V. The output voltage is a fixed ratio of half of the input voltage (VIN/2) and can supply a 20A load current after modification. This demo board has the option to deliver higher current load then then unmodified board with the addition of 15 chip capacitors (see below Fig 10 in User Guide).

The LTC®7820 is a fixed ratio high voltage high power switched capacitor/charge pump controller. The device includes four N-channel MOSFET gate drivers to drive external power MOSFETs in voltage divider, doubler or inverter configurations. The device achieves a 2:1 stepdown ratio from an input voltage as high as 72V, a 1:2 step-up ratio from an input voltage as high as 36V, or a 1:1 inverting ratio from an input voltage up to 36V. Each power MOSFET is switched with 50% duty cycle at a constant pre-programmed switching frequency. System efficiency can be optimized to over 99%. The LTC7820 provides a small and cost effective solution for high power, non-isolated intermediate bus applications with fault protection. The LTC7820 switching frequency can be linearly programmed from 100kHz to 1MHz.