Charge Pump Voltage Converter with the Microchip TC7662BEOA713

Voltage inversion and doubling are fundamental requirements in many electronic circuits, particularly when dealing with operational amplifiers, analog sensors, or display drivers that require a negative supply rail. While linear regulators and inductive switchers are common solutions, the charge pump voltage converter offers a compelling alternative, providing a simple, cost-effective, and inductorless means of power conversion. A premier component for this task is the Microchip TC7662BEOA713, a versatile and robust charge pump IC.

The TC7662BEOA713 is a monolithic CMOS voltage converter capable of efficiently inverting a positive input voltage to a corresponding negative output. For example, with a +5V input, it can generate a -5V output. Furthermore, by simply reconfiguring its external capacitor connections, the device can also function as a voltage doubler, making it an incredibly flexible component for a designer's toolkit. Its operation is elegantly simple, relying on a set of internal switches that charge an external "flying" capacitor on one phase of an internal oscillator and then reconfigure the circuit to transfer that charge to a second reservoir capacitor on the opposite phase, effectively inverting the polarity.

A key advantage of the TC7662BEOA713 is its high power efficiency, typically exceeding 99%. This high efficiency stems from its CMOS construction, which results in very low quiescent power consumption. The device operates across a wide input voltage range from 1.5V to 12V, making it suitable for both 3.3V/5V logic systems and higher voltage applications. Its internal oscillator frequency can be left to run at its default rate (typically 10kHz) or can be controlled by an external clock source, providing flexibility to avoid interference with sensitive analog circuits.

The SOIC-8 package (OA713) is industry-standard, allowing for easy prototyping and manufacturing. The design process with the TC7662BEOA713 is notably straightforward. A complete voltage inverter circuit requires only two external capacitors: one for the charge pump (flying capacitor) and one for the output (reservoir capacitor). This minimal component count drastically reduces the required board space, overall cost, and design complexity compared to magnetic-based switching regulators.

Typical applications are widespread, including generating negative supply rails for op-amps, powering RS-232 interface chips, and biasing LCD displays. Its ability to function without inductors also makes it immune to magnetic field interference and prevents it from emitting magnetic noise, a critical feature in noise-sensitive measurement and communication equipment.

ICGOOODFIND: The Microchip TC7662BEOA713 stands out as an exceptionally simple and effective solution for low-to-medium current voltage conversion. Its inductorless design, minimal external component requirement, and dual functionality as an inverter and doubler make it an indispensable IC for engineers seeking to optimize board space, cost, and performance in a wide array of electronic systems.

Keywords: Charge Pump, Voltage Inverter, Microchip TC7662BEOA713, Voltage Doubler, CMOS Converter