FAN2110 Datasheet, PDF (3/17 Pages) Fairchild Semiconductor – TinyBuck™, 3-24V Input, 10A, High-Efficiency, Integrated Synchronous Buck Regulator

Pin Configuration
Figure 3. MLP 5x6mm Pin Configuration (Bottom View)
Pin Definitions
Pin #
P1, 6-12
P2, 2-5
P3, 21-23
1
13
14
15
16
17
18
19
20
24
25
Name Description
SW Switching Node. Junction of high-side and low-side MOSFETs.
VIN Power Conversion Input Voltage. Connect to the main input power source.
PGND Power Ground. Power return and Q2 source.
BOOT
High-Side Drive BOOT Voltage. Connect through capacitor (CBOOT) to SW. The IC
includes an internal synchronous bootstrap diode to recharge the capacitor on this pin to
VCC when SW is LOW.
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.
ENABLE. Enables operation when pulled to logic HIGH or left open. Toggling EN resets the
EN 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.
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 > 2.2µF X5R / X7R capacitor.
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.
ILIM
Current Limit. A resistor (RILIM) from this pin to AGND can be used to program the current-
limit trip threshold lower than the internal default setting.
R(T)
Oscillator Frequency. A resistor (RT) from this pin to AGND sets the PWM switching
frequency.
FB Output Voltage Feedback. Connect through a resistor divider to the output voltage.
COMP
Compensation. Error amplifier output. Connect the external compensation network
between this pin and FB.
NC No Connect. This pin is not used.
RAMP
Ramp Amplitude. A resistor (RRAMP) connected from this pin to VIN sets the ramp amplitude
and provides voltage feedforward functionality.
© 2008 Fairchild Semiconductor Corporation
FAN2110 • Rev. 1.0.2
3
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