Sharp LC-32LE511E (serv.man2) Service Manual ▷ View online
29
LC-32LE511
LC-40LE511
LC-40LE531
LC-32LE511
LC-40LE511
LC-40LE531
12
4. POWER STAGE
17MB70 general power managment
block diagram is shown below.
17PW26 power board is used in 32”
17MB70 TV sets.
3,3V stby, 5V stby, 3,3V, 5V, 12V,
24V and 33V can be generated by
PW26.
Below blocks are generated by step-
downs and regulators on MB70
board.
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LC-32LE511
LC-40LE511
LC-40LE531
13
Power Blocks on MB70:
Below blocks are generated by step-downs and regulators on MB70 board.
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LC-32LE511
LC-40LE511
LC-40LE531
LC-32LE511
LC-40LE511
LC-40LE531
14
FAIRCHILD FAN2110 (U19-U20)
a) General Description
32
LC-32LE511
LC-40LE511
LC-40LE531
15
.
Pin Configuration
Figure 3. MLP 5x6mm Pin Configuration (Bottom View)
Pin Definitions
Pin #
Name Description
P1, 6-12
SW
Switching Node. Junction of high-side and low-side MOSFETs.
P2, 2-5
VIN
Power Input Voltage. Connect to the main input power source.
P3, 21-23
PGND
Power Ground. Power return and Q2 source.
1 BOOT
High-Side Drive BOOT Voltage. Connect through capacitor (C
BOOT
) to SW. The IC
includes an internal synchronous bootstrap diode to recharge the capacitor on this pin to
V
CC
when SW is LOW.
13 PGOOD
Power-Good Flag. An open-drain output that pulls LOW when FB is outside the limits
specified in electrical specs. PGOOD does not assert HIGH until the fault latch is enabled.
14 EN
ENABLE. Enables operation when pulled to logic HIGH or left open. Toggling EN resets the
regulator after a latched fault condition. This input has an internal pull-up when the IC is
functioning normally. When a latched fault occurs, EN is discharged by a current sink.
15 VCC
Input Bias Supply for IC. The IC’s logic and analog circuitry are powered from this pin.
This pin should be decoupled to AGND through a >1µF X5R/X7R capacitor.
16 AGND
Analog Ground. The signal ground for the IC. All internal control voltages are referred to
this pin. Tie this pin to the ground island/plane through the lowest impedance connection.
17 ILIM
Current Limit. A resistor (R
ILIM
) from this pin to AGND can be used to program the current-
limit trip threshold lower than the default setting.
18 R(T)
Oscillator Frequency. A resistor (R
T
) from this pin to AGND sets the PWM switching
frequency.
19 FB
Output Voltage Feedback. Connect through a resistor divider to the output voltage.
20 COMP
Compensation. Error amplifier output. Connect the external compensation network
between this pin and FB.
24 NC
No Connect. This pin is not used.
25 RAMP
Ramp Amplitude. A resistor (R
RAMP
) connected from this pin to VIN sets the ramp
amplitude and provides voltage feedforward functionality.
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