The compact (0.5″ × 0.7″) D24V10F5 synchronous buck voltage regulator takes an input voltage of up to 36 V and efficiently reduces it to 5 V while allowing for a maximum output current of 1 A. This regulator offers typical efficiencies between 85% and 90% and has a very low dropout, so it can be used with input voltages as low as a few hundred millivolts above 5 V. The pins have a 0.1″ spacing, making this board compatible with standard solderless breadboards and perfboards.
- Input voltage: [output voltage + dropout voltage] to 36 V (see below for more information on dropout voltage)
- Fixed 3.3 V, 5 V, 6 V, 9 V, or 12 V output (depending on regulator version) with 4% accuracy
- Maximum output current: 1 A
- Typical efficiency of 80% to 93%
- 500 kHz switching frequency (when not in power-save mode)
- 2 ms soft-start reduces in-rush current on power-up
- 200 μA typical no-load quiescent current
- Integrated over-temperature and over-current shutoff
- Small size: 0.7″ × 0.5″ × 0.14″ (18 mm × 13 mm × 3.5 mm)
The buck regulator has five connections: power good (PG). shutdown (SHDN), input voltage (VIN), ground (GND), and output voltage (VOUT).
The “power good” indicator, PG, is an open-drain output that drives low when the regulator’s output voltage falls below 80% or rises above 120% of its target output voltage. This output is also actively held low for the duration of the regulator’s 2 ms soft-start period and while the regulator is being disabled by the SHDN input or by over-temperature or over-current fault conditions. An external pull-up resistor is generally required to use this pin.
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 kΩ 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 μA.)
The input voltage, VIN, powers the regulator. Voltages between 3 V and 36 V can be applied to VIN, but 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 output voltage, VOUT, is fixed and depends on the regulator version: the D24V10F3 version outputs 3.3 V, the D24V10F5 version outputs 5 V, the D24V10F6 version outputs 6 V, the D24V10F9 version outputs 9 V, and the D24V10F12 version outputs 12 V.
The five connections are labeled on the back side of the PCB and are arranged with a 0.1″ spacing along the edge of the board for compatibility with solderless breadboards,connectors, and other prototyping arrangements that use a 0.1″ grid. You can solder wires directly to the board or solder in either the 5×1 straight male header strip or the 5×1 right-angle male header strip that is included.