MPQ8634 Step-Down Converters Monolithic Power Systems (MPS) MPQ8634 Step-Down Converters are fully integrated high-frequency, synchronous, buck converters. The MPQ8634A and MPQ8634B are compact solutions that achieve up to 12A (MPQ8634A) and 20A (MPQ8634B). The devices feature excellent load and line regulation over a wide input supply range. The devices operate at high efficiency over a wide output current load range.