The compact (0.32"×0.515") U3V12F9 switching step-up (or boost) voltage regulator takes an input voltage as low as 2.5 V and efficiently boosts it to 9 V. The pins have a 0.1" spacing, making this board compatible with standard solderless breadboards and perfboards.
These boost (step-up) voltage regulators generate higher output voltages from input voltages as low as 2.5 V. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) and have a typical efficiency between 80% 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 1.4 A. This regulator is available with a fixed 5 V, 9 V, or 12 V output:
We have several other boost regulators that you might consider as alternatives to these:
- Adjustable boost regulator 2.5-9.5 V – output voltage is adjustable from 2.5 to 9.5 V; works with input voltage as low as 1.5 V.
- Adjustable boost regulator 4-25 V – output voltage is adjustable from 4 to 25 V; works with input voltage as low as 1.5 V.
- input voltage: 2.5 V – VOUT
- fixed 5 V, 9 V, or 12 V output with 4% accuracy
- 1.4 A switch allows for input currents up to 1.4 A
- 2 mA typical no-load quiescent current
- integrated over-temperature shutoff
- small size: 0.515" × 0.32" × 0.1" (13 × 8 × 3 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 2.5 V and should not exceed the output voltage, VOUT. Please be wary of destructive LC spikes that might cause the input voltage to exceed VOUT (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.
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 our tests with typical power leads (~30" test clips), input voltages above 10 V caused voltage spikes in excess of 20 V. You can suppress such spikes by soldering a 33μF or larger electrolytic capacitor close to the regulator between VIN and GND.
More information about LC spikes can be found in our application note, Understanding Destructive LC Voltage Spikes.
- Size: 0.32″ × 0.515″ × 0.1″1
- Weight: 0.4 g1
- Minimum operating voltage: 2.5 V
- Maximum operating voltage: 9 V
- Maximum input current: 1.5 A2
- Output voltage: 9 V
- Reverse voltage protection?: N
- Maximum quiescent current: 2 mA
- 1. Without included optional headers.
- 2. Regulator may overheat at lower input currents when VIN is much lower than VOUT. Available output current is a function of VIN, VOUT, and the regulator efficiency.