Analysis of the power supply circuit of the main board bridge of the Intel H61 chipset.
The IntelH61 chipset motherboard often uses the NCP1587 generation bridge to power the PCH_1P1, as shown in figure 1.
Fig.1 PCH_1P1 supply power to generate circuit
1. The + 12V main supply circuit supplies the 5-pin power to the NCP1587 through resistance R224 and the other way through the D25 to the 1-pin power supply of the NCP1587.
2. The VCC5 is filtered by inductance and capacitance and sent to the D pole of Q18, and the 7-pin is pulled up to a high level through the chip interior.
3. NCP1587 chip turned on, 2-pin TG output high level Q18 on, VCC5 step-down output PCH_IP1, after inductive energy storage, capacitive filter output stable bridge-powered PCH_IPI.
4. PCH_IP1 through the resistance R579, R738 series shunt voltage to get 0.8V voltage, sent to the FB pin.
5.When the output voltage is higher than 1.1V and the voltage value after R579 and R738 partial voltage is higher than 0.8V, the chip will turn off Q18, turn on Q19 and Q20, form a circuit through Q19, Q20, and supply the bridge with inductance and capacitance discharge. This circulates the output of stable bridge power. The 1.05V bridge power generation circuit in the Intel H61 chipset motherboard is shown in figure 2.
Fig.2 PCH_1P05 supply Power generate to circuit
1. + 12V main power supply through the current limiting resistor R380 to power the NCP1587 and the other way through the D23 to power the BOOT pin.
2. PCH_VCC5_IN supplies power to the D pole of the Q74.
3. When the SLP_S3# is high normal, it is sent to the B pole of the three-pole Q69 through the resistor R349, making the Q69 on, lowering the G-pole voltage of the Q68, and making the Q68 cut-off.
4. The 7-pin of the # U26 is turned on through the internal pull-up, the 2-pin output PCH_UGI high, Q74 on, the PCH_VCC5_IN through the Q74 step-down, after the inductive energy storage, capacitance filtering output stable PCH_1PO5 bridge power supply.
5. PCH_1P05 is fed back to the FB pin of NCP1587 through R375 and R369 series shunt voltage. When the output voltage is raised and the voltage value after voltage division is higher than 1.1V, the chip closes the 2-pin PCH_UG1 output, outputs high level from 4-pin, and controls Q73 conduction to form a loop. The load is powered by the discharge of the secondary inductor and capacitor. When the feedback voltage is lower than L.1V, the chip will turn off Q73 and turn on Q74, which circulates the output of stable bridge power.
If you want to know more, our website has product specifications for the power supply circuit of the main board bridge of the Intel H61 chipset, you can go to ALLICDATA ELECTRONICS LIMITED to get more information