FAN73832 Datasheet, PDF (13/16 Pages) Freescale Semiconductor, Inc – Half-Bridge Gate-Drive IC

Typical Application Information
1. Normal Operating Consideration
The FAN73832 is a single PWM input, half-bridge, gate-
drive IC with programmable dead-time and shutdown
functions.
The dead-time is set with a resistor (R_DT) at the DT/SD
pin. The wide dead-time programming range provides
the flexibility to optimize drive signal timing for a
selection of switching devices (MOSFET or IGBT) and
applications.
The turn-on time delay circuitry (Dead-Time)
accommodates resistor values from 20kΩ to 200kΩ with
a dead-time proportional to the R_DT resistance.
If the DT/SD pin voltage decreases below 1.2V in the
normal operation, the IC enters shutdown mode.
The external dead-time setting resistor (R_DT) is at least
above 20KΩ for normal operation in typical applications.
2. Under-Voltage Lockout (UVLO)
The FAN73832 has an under-voltage lockout (UVLO)
protection circuit for high- and low-side channels to
prevent malfunction when V_DD and V_BS are lower than
the specified threshold voltage. The UVLO circuitry
monitors the supply voltage (V_DD) and bootstrap
capacitor voltage (V_BS) antepenult.
3. Layout Consideration
For optimum performance of the high- and low-side gate
drivers, considerations must be taken during printed
circuit board (PCB) layout.
3.1 Supply Capacitors
If the output stages are able to quickly turn-on a
switching device with a high value of current, the supply
capacitors must be placed as close as possible to the
device pins (V_DD and GND for the ground-tied supply, V_B
and V_S for the floating supply) to minimize parasitic
inductance and resistance.
3.2 Gate Drive Loop
Current loops behave like an antenna, able to receive
and transmit noise. To reduce the noise coupling/emis-
sion and improve the power switch turn-on and off per-
formances, gate drive loops must be reduced as much
as possible.
3.3 Ground Plane
Ground plane must not be placed under or nearby the
high-voltage floating side to minimize noise coupling.
© 2006 Fairchild Semiconductor Corporation
FAN73832 Rev. 1.0.2
13
www.fairchildsemi.com