A novel integrated 50 MHz POL solution utilizing internal OTA compensation

In this paper, a very high switching frequency Point of Load (POL) buck converter is proposed. The main feature of the proposed converter is small footprint, high efficiency, very low output ripple and excellent transient response. These superior features enable the replacement process of the inefficient LDO in many battery powered applications. The improved transient response has been achieved through the proposed new compensation technique utilizing the internal compensation network of the error amplifier which is usually realized using an operational transconductance amplifier (OTA). The small footprint has obtained through operating at very high switching frequency that has reduced the output filter´s size so that an integrated POL can be obtained. Moreover, using such high switching frequency enables the choice of small parasitic values for the output capacitor (ESL and ESR) and so a small output ripple is obtained. The careful design of the power FETs, gate drivers, and the layout leads to the obtained high efficiency. The designed buck converter has been optimized to operate at input voltages from 2.5V to 3.7V at constant switching frequency of 50 MHz. The proposed converter with the new compensation technique has been tested over a wide range of testing conditions of the load change rates and different I/O voltages. Results assure the advantages of the proposed converter and so its validity to replace the LDO.