An on-chip high-efficiency and low-noise DC/DC converter using divided switches with current control technique

An on-chip DC/DC converter with high efficiency and low-noise and easy implementation in LSIs is needed for single-supply voltage and low-power operation of LSIs. To obtain high-efficiency, fixed pulse-width modulation (PWM) and zero volt switching (ZVS) adaptive control are used. Operation with efficiency >90% is reported. However, these reports do not discuss low- noise switching operation and easy implementation. These are the most important points for practical use. The specifications for the DC/DC converter are: (1) easy implementation into LSIs as an on-chip DC/DC converter; (2) efficiency over 90% (at Io=80 mA, 3.0 V->2.0 V); (3) output noise below 30 mVp-p. A DC/DC converter which has both efficiency over 92% and 15 mV output noise is incorporated into an LSI.