Pololu 24V Step-Up/Step-Down Voltage Regulator S18V20F24
This powerful step-up/step-down regulator efficiently produces a fixed 24V output from input voltages between 3V and 30V while allowing a typical output current of up to 2A when the input voltage is close to the output voltage and offering typical efficiencies of 80% to 90%. Its ability to convert both higher and lower input voltages makes it useful for applications where the power supply voltage can vary greatly, as with batteries that start above but discharge below the regulated voltage.
These step-up/step-down regulators take an input voltage from 3V to 30V and increase or decrease it as necessary to produce a fixed 5V, 6V, 9V, 12V, or 24V output, depending on the version. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with a single-ended primary-inductor converter (SEPIC) topology, and they have a typical efficiency between 80% and 90%. The available output current is a function of the input voltage, output voltage, and efficiency (see the Typical Efficiency and Output Current section below), but it will be around 2A when the input voltage is close to the output voltage.
The S18V20x regulator family consists of the five fixed-output versions mentioned above along with two adjustable-output versions: the S18V20ALV offers an output range of 4V to 12V and the S18V20AHV offers an output range of 9V to 30V. The different versions of the board 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 four fixed-output versions of the S18V20x family.
The flexibility in input voltage offered by these regulators is especially well-suited for battery-powered applications in which the battery voltage begins above the desired output voltage and drops below the target as the battery discharges. Without the typical restriction on the battery voltage staying above the required voltage throughout its life, new battery packs and form factors can be considered. For example:
- A 4-cell battery holder, which might have a 6V output with fresh alkalines or a 4.0V output with partially discharged NiMH cells, can be used with the 5V version of this regulator to power a 5V circuit.
- A disposable 9V battery powering a 5V circuit can be discharged to under 3V instead of cutting out at 6V, as with typical linear or step-down regulators.
- The 6V version of this regulator can be used to enable a wide range of power supply options for a hobby servo project.
The no-load quiescent current will typically be around 1mA for most combinations of input and output voltages, though the combination of a very high output voltage and a very low input voltage (e.g. when boosting from 3V in to 30V out) can result in quiescent currents on the order of a few dozen milliamps.
The ENABLE pin can be used to put the board in a low-power state that reduces the quiescent current to between 10 and 20µA per volt on VIN (e.g. approximately 30µA with 3V in and 500µA with 30V in).
This regulator has built-in reverse-voltage protection, over-current protection, thermal shutdown (which typically activates at 165°C), and an under-voltage lockout that causes the regulator to turn off when the input voltage is below 2.5V (typical).
For powerful boost-only regulators, consider our U3V70x regulator family, which are typically more appropriate if you know that your input voltage will always be lower than your output voltage.
Features
- Input voltage: 2.9Vto32V1
- Fixed 5V, 6V, 9V, 12V, or 24V output with 4% accuracy
- Typical maximum output current: 2A (when input voltage is close to the output voltage; the Typical Efficiency and Output Current section below shows how the achievable output current depends on input and output voltages)
- Integrated reverse-voltage protection (up to 30V), over-current protection, over-temperature shutoff, and under-voltage lockout
- Typical efficiency of 80% to 90%, depending on input voltage, output voltage, and load
- Four 0.086″ mounting holes for #2 or M2 screws
- Compact size: 1.7″×0.825″×0.38″ (43×21×10mm)
- Smaller holes for 0.1″ header pins and larger holes for terminal blocks offer several options for connecting to the board
Dimensions
| Size: | 0.825″ × 1.7″ × 0.38″1 |
|---|---|
| Weight: | 7.5 g2 |
General specifications
| Minimum operating voltage: | 2.9 V |
|---|---|
| Maximum operating voltage: | 32 V3 |
| Maximum output current: | 2 A4 |
| Output voltage: | 24 V |
| Reverse voltage protection?: | Y5 |
| Maximum quiescent current: | 12 mA6 |