The Pololu 12V, 4.5A Step-Down Voltage Regulator is a powerful step-down (or buck) regulator that takes an input voltage of up to 50 V and efficiently reduces it to 12 V. The board measures only 1″ × 1″ yet delivers typical maximum continuous output currents between 2.3 A and 6.5 A, depending on the input voltage, which makes it well suited for powering moderate to large loads. An optional enable input with a precise cutoff threshold can be used to put the regulator in a low-power state with a current draw of 10 µA to 20 µA per volt on VIN. The regulator also features reverse voltage protection and a power-good output that indicates when the regulator cannot adequately maintain the output voltage.The regulators have input reverse voltage protection up to 40 V, output Undervoltage and overvoltage protection, over-current protection, and short-circuit protection. A thermal shutdown feature also helps prevent damage from overheating and a soft-start feature limits the inrush current and gradually ramps the output voltage on startup.FeaturesInput voltage: 13.3 V to 50 V (minimum input subject to dropout voltage considerations; see the dropout voltage section for details)Output voltage: 12 V with 4% accuracyTypical maximum continuous output current: 2.3 A to 6.5 A (see the maximum continuous output current graph below)Typical efficiency of 90% to 95%, depending on input voltage, output voltage, and load (see the efficiency graph below)Switching frequency: ~500 kHz under heavy loadsPower-save mode with an ultrasonic operation that increases light load efficiency by reducing switching frequency, but keeps it above the audible range (20 kHz)2 mA to 4 mA typical no-load quiescent current (see the quiescent current graph below)Enable input with the precise cutoff threshold for disconnecting the load and putting the regulator into a low-power state that draws approximately 10 µA to 20 µA per volt on VIN"Power good" output indicates when the regulator cannot adequately