This 5 V boost (step-up) voltage regulator generates higher output voltages from input voltages as low as 0.5 V, and it also automatically switches to a linear down-regulation mode when the input voltage exceeds the output. This makes it great for powering 5 V electronics projects from 1 to 3 NiMH, NiCd, or alkaline cells or from a single lithium-ion cell.
When boosting, this module acts as a switching regulator (also called switched-mode power supplies (SMPS) or DC-to-DC converters) and has a typical efficiency between 70% to 90%. The available output current is a function of the input voltage, output voltage, and efficiency (see Typical Efficiency and Output Current section below), but the input current can typically be as high as 1.2 A. This regulator is also available with a fixed 3.3 V output, and very similar 3.3V, 5V, and adjustable-output versions are available with a true shutdown option that turns off power to the load.
The regulator’s thermal shutdown engages at around 140°C and helps prevent damage from overheating, but it does not have short-circuit or reverse-voltage protection.
- Input voltage: 0.5 V to 5.5 V
- Fixed 5 V output with 4% accuracy
- Automatic linear down-regulation when the input voltage is greater than the output voltage
- 1.2 A switch allows for input currents up to 1.2 A
- Good efficiency at light load: <1 mA typical no-load quiescent current, though it can exceed 1 mA for very low input voltages
- Integrated over-temperature shutoff
- Small size: 0.35″ × 0.45″; × 0.1″ (9 × 11.5 × 2.5 mm)
Using the Regulator
The boost regulator has three connections: input voltage (VIN), ground (GND), and output voltage (VOUT).
The input voltage, VIN, must be at least 0.5 V for the regulator to turn on. However, once the regulator is on, the input voltage can drop as low as 0.3 V and the 5 V output voltage will be maintained on VOUT. Unlike standard boost regulators, this regulator has an additional linear down-regulation mode that allows it to convert input voltages as high as 5.5 V down to 5 V for small to moderate sized loads. When the input voltage exceeds 5 V, the regulator automatically switches to this down-regulation mode. The input voltage should not exceed 5.5 V. Please be wary of destructive LC spikes that might cause the input voltage to surpass 5.5 V (see below for more information).
The 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 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 3×1 straight male header strip or the 3×1 right-angle male header strip that is included.
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, this switching regulator typically has an efficiency of 70 to 90%.
The maximum achievable output current is approximately proportional to the ratio of the input voltage to the output voltage. If the input current exceeds the switch current limit (typically somewhere between 1.2 and 1.5 A), the output voltage will begin to drop. Additionally, the maximum output current can depend on other factors, including the ambient temperature, air flow, and heat sinking.
LC Voltage Spikes
When connecting voltage to electronic circuits, the initial rush of current can cause damaging voltage spikes that are much higher than the input voltage. In Pololu's tests with typical power leads (~30″ test clips), input voltages above 4.5 V caused voltage spikes that could potentially damage the regulator. You can suppress such spikes by soldering a 33 μF or larger electrolytic capacitor close to the regulator between VIN and GND.
More information about LC spikes can be found in Pololu's application note, Understanding Destructive LC Voltage Spikes.
This product is listed in:
Documentation and Resources:
- The Maker Revolution
The Maker Revolution celebrates the creation of new devices and the modification of existing ones - the transition from a consumer buying goods to eventually having a major part in their creation. The Maker Revolution places strong emphasis on free (...
- How to Use DC Regulators/Converters
So, you might have the best project in the world, an amazing idea and design, but no matter how clever your circuitry or how advanced your prototype is, unless you can power your project correctly, it all counts for nothing. Often you will need diffe...
- Powering Portable Projects: Batteries
Want to make your project portable? We've put together a quick guide to get you up to speed on battery options and help you decide which batteries might be best for your project. Batteries are a whole different game to plug packs and benchtop power s...
- Our recommendation on Breadboard Power Supplies
So, you’re looking for the right way to power your breadboard? You’ve found that your Arduino Uno just doesn’t quite have the juice to power up your circuit. It's likely that the microcontroller can output around 400mA when using th...
Exact shipping can be calculated on the view cart page (no login required).
We deliver Australia-wide with these options:
- $3 for Small Items (3-7 days, not tracked, only available on selected small items)
- $6.95 for Standard Post (2-4 days, tracked)
- $8.95 for Express Post (Overnight for Australia Post Next Day Network, tracked)
- Pickup - Free! Only available to customers who live in the Newcastle region (only after we email you to notify your order is ready)
International Orders - the following rates are for New Zealand and will vary for other countries:
- $11.49 for Pack and Track (3+ days, tracked)
- $16.50 for Express International (2-5 days, tracked)
If you order lots of gear, the postage amount might increment 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.