Charge Pump Voltage Inverter: 1.8-5.3V, 60mA

This board is a charge pump voltage inverter that converts an input voltage between 1.8 V and 5.3 V to a corresponding negative output voltage, with a typical efficiency of over 80%. The inverter can deliver a continuous output current of 60 mA across most of its operating range, making it a simple solution for applications requiring a lower-power negative supply, including sensor biasing and bipolar op-amp circuits.

Unlike a voltage regulator, which produces a constant output voltage from a range of input voltages, this inverter does not have a set output voltage; the module’s negative output voltage varies proportionally to the positive input voltage that it receives. However, you can get a regulated negative voltage by powering the inverter with a pre-regulated supply voltage. For example, with a fixed 5 V supply, the module produces a fixed -5 V on its output; with a 3.3 V input, the output is -3.3 V. Note that the magnitude of the output voltage decreases as the output current increases; please see the graphs at the bottom of this page for a more detailed characterization.

Using the inverter

Connections

The voltage inverter has three connections: input voltage (VIN), ground (GND), and output voltage (VOUT). 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.

The input voltage, VIN, should be between 1.8 V and 5.3 V. The output voltage, VOUT, is inverted from the input (nominally, VOUT = −VIN).