High-efficiency 4-output power supply controller using power management chip MAX1999

High-efficiency 4-output power supply controller using power management chip MAX1999

The power supply circuit of the laptop motherboard is usually controlled by a power management chip
. As shown in the figure, the power management chip MAX 1999 can convert one DC voltage provided by the battery into multiple DC voltage outputs. The MAX 1999 chip has two sets of PWM
signal generation circuits. The battery or adapter supplies power to the switching field effect transistor and control chip respectively.
    After the MAX 1999 chip gets the voltage, it starts to generate a PWM signal. The LX5 and DL5 pins output a set of switching pulses with opposite phases
to drive the field effect transistors Nl and N2 respectively, so that the two field effect transistors work alternately and convert the DC voltage of the battery into a switching signal.
After filtering by L5 and c5, the output Stabilized DC 5v voltage.
    At the same time, the LX3 and DL3 pins of the MAX 1999 chip also output a set of switching pulses with opposite phases to drive the field effect transistors
N3 and N4 respectively, so that the two field effect transistors work alternately and convert the DC voltage of the battery into a switching signal, which is passed through L3 After filtering with C3, the output is
a regulated DC voltage of 3.3 V.