Three-Phase MOSFET Gate Driver IC

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Design example

Three-Phase MOSFET Gate Driver IC

Six gate-driver outputs control external N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) in a three-phase bridge. Resistor-set deadtime and high-side bias support help integrate the external power stage.

Design targets

Gate-driver configuration
Six outputs for three half-bridges using external N-channel MOSFETs
Switch-node voltage class
80 V; operating margins and transients require evaluation
Gate-driver bias supply
7–15 V; startup depends on undervoltage-lockout conditions
Peak gate turn-on current
0.5 A target based on a typical reference value at 12 V bias, 0 V output and 25 °C junction temperature
Deadtime control
Programmable using an external resistor
High-side bias
Bootstrap with charge-pump support; external components required
Pin compatibility
24-pin signal-assignment compatibility target
Ambient-temperature range
−40 to +125 °C

Practical operating notes

  • Design is complete and pre-silicon. The listed specifications are design targets, not measured results. Typical reference values are not guaranteed performance limits for this design.
  • The six outputs drive the gates of external power MOSFETs. The 0.5 A figure is peak gate turn-on current, not motor-load current. An external controller supplies pulse-width modulation (PWM) commands and commutation; the power stage, current sensing and fault response require system-level design.
  • The 80 V switch-node class requires appropriate operating margin and transient control. The 7–15 V driver-bias target does not guarantee startup at 7 V under every condition; evaluate undervoltage-lockout thresholds and their settings.
  • Deadtime is set by an external resistor and can be disabled. Review controller timing, high-side input inversion and low-side override behavior to prevent unintended simultaneous conduction.
  • High-side operation uses bootstrap bias with charge-pump support and requires external bootstrap diodes and capacitors. Evaluate startup and refresh behavior, gate charge, leakage and duty cycle before relying on extended high-side on-time.
  • Matching the 24-pin signal assignments is a compatibility target. Package variant, footprint, electrical and timing behavior, thermal limits and board-level operation still require validation before interchangeability can be established.

Possible applications

  • Brushless DC (BLDC) motor drives with an external power stage
  • AC motor inverter control with an external power stage
  • Switched-reluctance motor drives with a suitable external power stage

Discuss your gate-drive requirements and external power-stage constraints.

Discuss an Application