Pololu 3.3V, 500mA Step-Down Voltage Regulator D24V5F3

Description

The compact (0.4? × 0.5?) D24V5F3 synchronous buck voltage regulator takes an input voltage of up to 36 V and efficiently reduces it to 3.3 V while allowing for a maximum output current of 500 mA . This regulator offers typical efficiencies between 80% and 90% and has a very low dropout, so it can be used with input voltages as low as a few hundred millivolts above 3.3 V. The pins have a 0.1? spacing, making this board compatible with standard solderless breadboards and perfboards. The D24V5Fx family of buck (step-down) voltage regulators generates lower output voltages from input voltages as high as 36 V. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) and have a typical efficiency between 80% to 93%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. These regulators have a power-save mode that activates at light loads and a low quiescent (no load) current draw, which make them well suited for low-power applications that are run from a battery. These regulators are available in eight different fixed output voltages: The different versions of this regulator all look very similar, so the bottom silkscreen includes a blank space where you can add your own distinguishing marks or labels. This product page applies to all eight versions of the D24V5Fx family. The regulators feature short-circuit/over-current protection, and thermal shutdown helps prevent damage from overheating. The boards do not have reverse-voltage protection. If you need more output current, consider the very similar D24V10Fx family of step-down voltage regulators, which can deliver up to 1 A in several different output voltages: The picture on the right shows a 1 A D24V10Fx regulator next to a 0.5 A D24V5Fx regulator and a common 7805 linear regulator in a TO-220 package. The buck regulator has four connections: shutdown ( SHDN ), input voltage (VIN), ground (GND), and output voltage (VOUT). The SHDN pin can be driven low (under 0.4 V) to turn off the output and put the board into a low-power state. There is a 100 k? pull-up resistor between the SHDN pin and VIN, so if you want to leave the board permanently enabled, the SHDN pin can be left disconnected. While the SHDN pin is being driven low, the current draw of the regulator is dominated by the current through the pull-up resistor and will be proportional to the input voltage. (At 36 V in it will draw about 360 ?A.) The input voltage, VIN, powers the regulator. Voltages between 3 V and 36 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 3 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for graphs of dropout voltages as a function of the load). Additionally, please be wary of destructive LC spikes (see below for more information). The o