The ADP3161 is a highly efficient dual output synchronous buck switching regulator controller optimized for converting a 5 V or 12 V main supply into the core supply voltage required by highperformance processors such as Pentium III. The ADP3161 uses an internal 4-bit DAC to read a voltage identification (VID) code directly from the processor, which is used to set the output voltage between 1.3 V and 2.05 V. The ADP3161 uses a current mode PWM architecture to drive two logic-level outputs at a programmable switching frequency that can be optimized for VRM size and efficiency. The output signals are 180 degrees out of phase, allowing for the construction of two complementary buck switching stages. These two stages share the dc output current to reduce overall output voltage ripple. An active current balancing function ensures that both phases carry equal portions of the total load current, even under large transient loads, to minimize the size of the inductors.