A55 chip board 1.1V bridge power supply analysis.

The A55 chipset main bridge power supply mostly uses operation plus MOS tube depressurization to provide 1.1V power supply, as shown in figure 1.

Fig.1 A 55 chipset motherboard power supply schematic diagram.

 Figure 1 A55 chipset main board bridge power supply schematic diagram.

1.Short switch, bridge output SLP_S3# high level signal to the G1 pin of Q57, using D1 and S1 conduction, get low level to G2 foot, make D2 and S2 cut off, obtain high level 1.1V_REF.

2. The FCH_1P2V_REF passes through the resistors R379 and R377 sub-voltages to give the 1.1V_REF a 1.1V voltage to the 10 pin of the U27C, a 10-pin voltage higher than the 9-pin voltage, and an 8-pin output high-level feed to the control poles of Q56 and Q55, using both Q55 and Q56 on at the same time. The VCC_DDR memory power supply depresses the VCCIP1 voltage and supplies the bridge with power.

This article is from Allicdata Electronics Limited.