In stock, ships same business day if ordered before 2PM
Delivered by Tue, 5th of Mar
These step-up/step-down regulators take an input voltage from 3 V to 30 V and increase or decrease it as necessary to produce a fixed 5 V, 6 V, 9 V, 12 V, or 24 V 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 2 A 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 4 V to 12 V and the S18V20AHV offers an output range of 9 V to 30 V. 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:
The no-load quiescent current will typically be around 1 mA 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 3 V in to 30 V 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 20 µA per volt on VIN (e.g. approximately 30 µA with 3 V in and 500 µA with 30 V 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 2.5 V (typical).
For powerful boost-only regulators, consider Pololu's U3V70x regulator family, which are typically more appropriate if you know that your input voltage will always be lower than your output voltage.
1 32 V is the absolute maximum operating voltage; the recommended maximum operating voltage is 30 V, which is the limit of the reverse voltage protection.
Using the regulator
This step-up/step-down regulator has four connections: input voltage (VIN), ground (GND), and output voltage (VOUT), and ENABLE.
The input voltage, VIN, should be between 2.9 V and 32 V. Lower input voltages can cause the regulator to shut down or behave erratically; higher input voltages can destroy the regulator, so you should ensure that noise on the input is not excessive. 32 V should be treated as the absolute maximum input voltage. Pololu's recommended maximum operating voltage is 30 V, which is the limit of the reverse voltage protection.
The regulator is enabled by default: a 100 kO pull-up resistor on the board connects the ENABLE pin to reverse-protected VIN. The ENABLE pin can be driven low (under 0.7 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from ENABLE to VIN and by the reverse-voltage protection circuit, which will draw between 10 µA and 20 µA per volt on VIN when ENABLE is held low (e.g. approximately 30 µA with 3 V in and 500 µA with 30 V in). If you do not need this feature, you should leave the ENABLE pin disconnected. Note that the SEPIC topology has an inherent capacitor from input to output; therefore, the output is not completely disconnected from the input even when the regulator is shut down.
The connections are labeled on the back side of the PCB, and the board offers several options for making electrical connections. You can solder the included 2-pin 5mm-pitch terminal blocks to the two pairs of larger holes on the ends of the board. Alternatively, if you want to use this regulator with a solderless breadboard, 0.1"-pitch connectors, or other prototyping arrangements that use a 0.1"grid, you can solder pieces of the included 9×1 straight male header strip to the 0.1"-spaced smaller holes (each large through-hole has a corresponding pair of these smaller holes). For the most compact installation, you can solder wires directly to the board.
The board has four 0.086" mounting holes intended for #2 or M2 screws. In applications where mounting screws are not used and wires are soldered directly to the board, the insulated part of the wires can be passed through the mounting holes for strain relief. The picture above shows an example of this with 20 AWG wire, which was close to the limit of what would fit through the mounting holes.
Typical efficiency and output current
The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. As shown in the graphs below, these switching regulators have an efficiency of 80% to 90% for most combinations of input voltage, output voltage, and load.
Pololu manufacture these boards in-house at Pololu's Las Vegas facility, which gives Pololu the flexibility to make batches of regulators with customized components to better meet the needs of your project. For example, if you have an application where the input voltage will always be below 20 V and efficiency is very important, Pololu can make these regulators a bit more efficient at high loads by replacing the 30V reverse voltage protection MOSFET with a 20V one. Pololu can also customize the set output voltage. If you are interested in customization, please contact us.
The maximum achievable output current of the board varies with the input voltage but also depends on other factors, including the ambient temperature, air flow, and heat sinking. The graphs below show output currents at which this voltage regulator’s over-temperature protection typically kicks in after a few seconds. These currents represent the limit of the regulator’s capability and cannot be sustained for long periods, so the continuous currents that the regulator can provide are typically several hundred milliamps lower.
During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.
People often buy this product together with:
|Pololu 5V Step-Up/Step-Down Voltage Regulator S18V20F5
|0.825" × 1.7" × 0.38"1
|Minimum operating voltage:
|Maximum operating voltage:
|Maximum output current:
|Reverse voltage protection?:
|Maximum quiescent current:
|PCB dev codes:
|Other PCB markings:
|0J7765, blank white box
This DXF drawing shows the locations of all of the board’s holes.
Exact shipping can be calculated on the view cart page (no login required).
Products that weigh more than 0.5 KG may cost more than what's shown (for example, test equipment, machines, >500mL liquids, etc).
We deliver Australia-wide with these options (depends on the final destination - you can get a quote on the view cart page):
Non-metro addresses in WA, NT, SA & TAS can take 2+ days in addition to the above information.
Some batteries (such as LiPo) can't be shipped by Air. During checkout, Express Post and International Methods will not be an option if you have that type of battery in your shopping cart.
International Orders - the following rates are for New Zealand and will vary for other countries:
If you order lots of gear, the postage amount will increase based on the weight of your order.
Our physical address (here's a PDF which includes other key business details):
Unit 18, 132 Garden Grove Parade
Take a look at our customer service page if you have other questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.
Have a product question? We're here to help!
Makers love reviews as much as you do, please follow this link to review the products you have purchased.