Sharp LC-40LS340E, Руководство по обслуживанию

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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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LC-40LS340