Home|FAQ Search| In the BU48xx/BU49xx/BD48xx/BD49xx series, when the power supply drops below the detection voltage, delayed output switching will occur. If the detection voltage recovers during this delay, what will happen?
Reference data regarding the specifications for reset recovery time is contained in the technical notes. With the BU4845, the rise time (tPLH) is 23.3µs and the fall time (tpHL) is 275.9µs, while for the BU4945 the rise and fall times are 3.5µs and 354.3µs, respectively. (VDD=4.3V←→5.1V) For cases where the power supply fluctuation is faster than this time the output will become delayed. If within this reaction time the power supply recovers no reaction from the output will occur. The output behavior may differ depending on power supply voltage fluctuations or changing conditions. Therefore, ROHM recommends that the customer ensures sufficient margins in their designs.