FAN6520B Fairchild Semiconductor, FAN6520B Datasheet - Page 2

• Manufacturer Part Number: FAN6520B
• Description: Single Synchronous Buck PWM Controller
• Manufacturer: Fairchild Semiconductor

FAN6520B Rev. 1.0.3
Pin Configuration
Pin Definitions
Pin #
1
2
3
4
5
6
7
8
Pin Name
COMP/SD
BOOT
HDRV
LDRV
GND
VCC
SW
FB
Bootstrap Supply Input. Provides a boosted voltage to the high-side MOSFET driver.
Connect to bootstrap capacitor and diode as shown in Figure 1.
High Side Gate Drive Output. Connect to the gate of the high-side power MOSFET(s).
This pin is also monitored by the adaptive shoot-through protection circuitry to determine
when the upper MOSFET has turned off.
Ground. The signal and power ground for the IC. Tie this pin to the ground island/plane
through the lowest impedance connection available. Connect directly to source of low-side
MOSFET(s).
Low Side Gate Drive Output. Connect to the gate of the low-side power MOSFET(s).
This pin is also monitored by the adaptive shoot-through protection circuitry to determine
when the lower MOSFET has turned off.
VCC. Provides bias power to the IC and the drive voltage for LDRV. Bypass with a good
quality ceramic capacitor (X7R or X5R) as close to this pin as possible.
Feedback. This pin is the inverting input of the internal error amplifier. Use this pin, in
combination with the COMP pin, to compensate the voltage-control feedback loop of the
converter.
COMP/SD. This is a multiplexed pin. During operation, the output of the error amplifier
drives this pin. Pulling COMP to a level below 0.8V disables the controller. Disabling the
controller causes the oscillator to stop, the HDRV and LDRV outputs to be held low, and the
soft-start circuitry to re-arm. Connect a 75k resistor between VCC and COMP/SD pin to
pull up.
Switch Node Input. Connect as shown in Figure 1. The SW pin provides return for the
high-side bootstrapped driver, is a sense point for the adaptive shoot-thru protection.
BOOT
HDRV
LDRV
GND
FAN6520BM 8-pin SOIC Package
1
2
3
4
FAN6520B
Pin Function Description
2
8
7
6
5
SW
COMP/SD
FB
VCC
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