Page 63 - GIGABYTE Service Manual-v3.0-110101

3.2.8 VCC1_1

VCC1_1 circuit is separated into 4 sections:
Power MOSFET

PWM Controller
Feedback circuit
Over Voltage Controller

Figure 3-17: VCC1_1

Power MOSFET Section:
The section Includes Q47, Q45, L4, L6, and R, C. The output VCC1_1 (1.1V) depends
on input VCC3 and control gate HG , LG of high side MOSFET Q47 and low side
MOSFET Q45. The control gate signal must be a waveform.

PWM Controller Section:
The section Includes PWM U9 and R, C. The PWM controller operates from 12V
Supply voltage. The HGATE and UGATE output to MOSFET depends on pin 6 FB
0.6V and pin 7 COMP VCC1_1_EN 1.7V. If pin FB, pin COMP (EN) fail, we can

check the feedback circuit section, and also check EN from divided voltage of R295
and R309.
Feedback Circuit Section:
The section Includes R317, R318. For feedback FB, we can read a voltage of 0.6 V.

Over Voltage Controller Section:
The section Includes U15 which is three voltage channel console , the uP6262 is a high
precision voltage console consisting of three sets I2C programmable current DACs, the
over voltage 0_6LEVEL input from U15 .

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