The VS pin is the high-side floating supply return. It connects to the midpoint of the half-bridge power stage between the high-side source and low-side drain. Because it swings dynamically between ground and the high-voltage rail, the high-side driver circuitry references its floating supply (VB) against this pin.
FAN7382 Datasheet: Pinout, Voltage, and Applications
AnswerSelection guide
The FAN7382 is a 600V half-bridge gate driver from onsemi designed to drive high-side and low-side N-channel MOSFETs or IGBTs in power supplies and motor drives. It operates with a VCC supply of 10V to 20V and features ±2A peak output drive capability.
The FAN7382 is an industry-standard monolithic half-bridge gate driver manufactured by onsemi. It is specifically designed for high-voltage, high-speed driving applications, capable of operating with high-side rail voltages up to +600V. Hardware engineers frequently select this IC for half-bridge and full-bridge topologies such as brushless DC motor drivers, uninterruptible power supplies (UPS), and DC-DC power converters.
Understanding the core electrical characteristics, package variants like the FAN7382MX and FAN7382M1X, and proper pin configuration is vital for reliable implementation. The driver utilizes bootstrap techniques for the high-side supply, reducing component count while delivering robust switching performance with TTL and CMOS compatible logic inputs.
Pinout and COM Function
The FAN7382 is available in two primary package options: the 8-SOP (FAN7382MX) and the 14-SOP (FAN7382M1X). While the 8-SOP provides a compact footprint, the 14-SOP includes additional no-connect (NC) pins that help engineers achieve greater physical separation and spacing for improved creepage and noise immunity.
The standard 8-pin package configuration includes:
- VCC (Pin 1): Low-side logic supply voltage (10V to 20V).
- IN (Pin 2): Logic input for control of gate outputs.
- COM (Pin 3): Low-side return and common ground reference for logic and low-side circuitry.
- LO (Pin 4): Low-side gate drive output.
- VS (Pin 5): High-side floating supply return.
- HO (Pin 6): High-side gate drive output.
- VB (Pin 7): High-side floating supply voltage.
- NC (Pin 8): Not internally connected (in 8-SOP variant).
The COM pin serves as the reference ground for the low-side control section and must be tied cleanly to the system ground plane. Designers must take care with PCB layout around COM and VS to prevent transient voltage spikes from disrupting gate logic.
Voltage Ratings and Key Specifications
Electrical parameters define the operating envelope for power electronics designs. The FAN7382 incorporates built-in under-voltage lockout (UVLO) protection on both the low-side (VCC) and high-side (VBS) floating supplies to prevent erratic MOSFET switching during low-voltage conditions.
- High-Side Floating Supply Voltage (VBS): Up to 600V maximum rating.
- Logic Supply Voltage (VCC): 10V to 20V recommended operating range.
- Peak Output Current: ±2A source and sink capability, allowing for fast gate charging and discharging.
- Propagation Delay: Approximately 200ns typical turn-on and turn-off delay.
- Operating Temperature Range: -40°C to +125°C.
For complete electrical tables and timing diagrams, consult the official FAN7382 datasheet from onsemi.
Application Recommendations and Layout Guidelines
Successful deployment of half-bridge drivers requires strict attention to passive component selection and circuit layout. A fast-recovery bootstrap diode and a low-ESR ceramic bootstrap capacitor (typically 0.1µF to 1µF) must be connected between the VB and VS pins to maintain the high-side floating supply.
Engineers should place a 0.1µF decoupling capacitor directly across the VCC and COM pins as close to the package as possible. Adding external gate resistors in the range of 5Ω to 10Ω in series with LO and HO helps dampen parasitic ringing and limits peak current surges. Adequate dead-time must be programmed into the controller PWM signals to prevent shoot-through currents across the half-bridge power stage.