The Pololu adjustable boost regulator is a very flexible switching regulator (also called a switched-mode power supply, SMPS, or DC-to-DC converter) that can generate voltages higher than its input voltage. Pololu offer two adjustable ranges: approximately 2.5 V to 9.5 V and 4 V to 25 V. The output voltage can be set using the trimmer potentiometer in the upper-right corner of the board. The input voltage range is 1.5 V to 16 V (the input voltage should be kept below the output voltage). The integrated 2 A switch allows for output currents high enough to drive small motors, as in Pololu's 3pi robot, and allows large voltage gains, such as obtaining 24 V from two NiMH or NiCd cells.
Some example applications include:
Note: For high-volume applications, this product can be customized with fixed output voltages ranging from 2 V to 30 V.
Feature summary
Using the Boost Regulator
Connections
The boost regulator has just three connections: the input voltage, ground, and the output voltage. These three connections are labeled on the back side of the PCB, and they are arranged with a 0.1" spacing along the edge of the board for compatibility with standard solderless breadboards and perfboards and connectors that use a 0.1" grid. You can solder wires directly to the board or solder in either the 3×1 straight male header strip or the 3×1 right-angle male header strip that is included.
Setting the output voltage
The output voltage can be adjusted using a meter and a light load (e.g. a 10 kO resistor). Turning the potentiometer clockwise increases the output voltage. The output voltage can be affected by a screwdriver touching the potentiometer, so the output measurement should be done with nothing touching the potentiometer.
Warning: You should be careful not to use an input voltage that exceeds the output voltage setting, so Pololu recommend setting the output voltage with the input voltage around or below 2.5 V (e.g. using one or two alkaline batteries). Note that the potentiometer has no physical end stops, which means that the wiper can be turned 360 degrees and into an invalid region in which the output voltage is set to approximately 2.5 V (for both the 2.5 V to 9.5 V and 4 V to 25 V versions).
Output voltage settings for the adjustable boost regulators. |
---|
The absolute limit for the input voltage is double the output voltage setting. For example, if the output is set to 6 V, the input must not exceed 12 V. Once the input exceeds the output set point, the output voltage will rise with the input voltage since the input is connected to the output through an inductor and a diode.
Note: The trimmer potentiometer is not rated for continual adjustment back and forth; the intended application is to set the output voltage a few times in its life.
Efficiency and available output current
The available output current depends on the input and output voltages. The input current is limited to approximately 2 A, and, as shown in the graphs below, the efficiency is typically 80% to 90%. Therefore, the maximum available current will be approximately 800 mA when doubling the input voltage and approximately 400 mA when quadrupling the input voltage. At high output powers, the 20% lost in the regulator will cause substantial heating, which can limit the available output power (the regulator will automatically shut off if its internal temperature gets too high). At low output currents and high input and output voltages, the efficiency drops closer to 50%, though the lower power involved prevents heating from being an issue. Some output voltages shown in the efficiency graphs below can only be achieved using the 4-25V adjustable boost regulator.
LC Voltage Spikes
When connecting voltage to electronic circuits, the initial rush of current can cause voltage spikes that are much higher than the input voltage. If these spikes exceed the regulator’s absolute maximum voltage (16 V), the regulator can be destroyed. If you are connecting more than approximately 10 V or your power leads or supply has high inductance (e.g. your input leads are longer than a few inches), Pololu recommend soldering a 33µF or larger electrolytic capacitor close to the regulator between VIN and GND. The capacitor should be rated for at least 25 V.
More information about LC spikes can be found in Pololu's application note, Understanding Destructive LC Voltage Spikes.
People often buy this product together with:
Pololu Adjustable Boost Regulator 4-25V |
QTR-8A Reflectance Sensor Array |
Pololu Micro Metal Gearmotor Bracket Pair - Black |
Dimensions
Size: | 0.42" × 0.88" × 0.23"1 |
---|---|
Weight: | 1.6 g1 |
General specifications
Minimum operating voltage: | 1.5 V |
---|---|
Maximum operating voltage: | 9.5 V2 |
Maximum input current: | 2 A |
Minimum output voltage: | 2.5 V |
Maximum output voltage: | 9.5 V |
Reverse voltage protection?: | N |
Maximum quiescent current: | 6 mA3 |
Identifying markings
PCB dev codes: | reg03a |
---|---|
Other PCB markings: | 0J1213 |
Notes:
File downloads
Dimension diagram of the Pololu Adjustable Boost Regulator 2.5-9.5V and 4-25V (292k pdf)
3D model of the Pololu Adjustable Boost Regulator 2.5-9.5V and 4-25V (4MB step)
Drill guide for Pololu Adjustable Boost Regulator 2.5-9.5V and 4-25V (26k dxf)
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
Adamstown
NSW, 2289
Australia
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.
Product Comments