Quicker Announces New Power Technology
Troubleshooting the return circuit instability issue

In order to solve the fundamental challenges of response performance and stable operation required of power ICs, ROHM has established high-speed load response technology that can maximize the response performance of power ICs.

ROHM Co., Ltd. recently announced the load response characteristics (hereinafter referred to as response performance) of various power ICs, including DC/DC converter ICs. announced a new power technology, 'QuiCur™', which improves response speed and voltage stability during back-end circuit operation.

The power IC constantly monitors the output voltage to realize a stable power function, and is equipped with a circuit (hereinafter, a feedback circuit) that finely adjusts the output voltage by comparing it with the reference voltage within the IC.

When pursuing an excessively fast response, the circuit operation becomes unstable, the output voltage oscillates, and the capacitance of the output capacitor (hereinafter, output capacitor capacitance) also affects the response speed, so the desired response performance cannot be achieved.

By incorporating 'QuiCur™' into the power IC, it is possible to achieve response performance to the limit without the power IC's feedback circuit becoming unstable.

QuiCur™ divides the signal processing roles of response speed (control system) and voltage stability (compensation system) to maximize response performance.

This solves two problems that were problematic in the feedback circuit of existing power ICs: 'an unusable region occurs in the frequency region lower than the unstable region' and 'the zero-crossing frequency (f0) changes due to the output capacitor capacity'.

First, the problem of 'unusable area occurrence' was solved by providing a dedicated error amplifier that does not cause an unusable area in the feedback circuit.

For the second task, 'zero cross frequency change', a technology was introduced that allows the amplification rate (Gain) to be adjusted by current driving by providing a second-stage dedicated error amplifier.

The zero-crossing frequency changes due to the capacitance of the output capacitor being connected, but the amplification factor changes accordingly.By adjusting the zero cross frequency, it is possible to set the zero cross frequency to the limit (border) of the unstable region and the stable control region.

A system constructed by dividing the roles of these two error amplifiers can be widely applied to power supply ICs such as DC/DC converter ICs and linear regulators equipped with feedback circuits.

Meanwhile, ROHM is promoting the commercialization of power supply ICs equipped with 'QuiCur™' technology, and plans to begin sample shipments of DC/DC converter ICs in April 2022 and linear regulators in July 2022.