Allegro MicroSystems AHV85000 & AHV85040 Isolated-Driver Chipsets

Allegro MicroSystems AHV85000 and AHV85040 GaN FET Isolated-Driver Chipsets are cost-optimized for gallium-nitride (GaN) field-effect-transistor (FET) devices. The devices provide a self-powered isolated gate drive solution when combined with one of the recommended external transformers ideal for GaN FETs in multiple applications and topologies.

The Allegro MicroSystems AHV85000 and AHV85040 Chipsets transfer both the pulse-width-modulated (PWM) signal and the gate bias power through the external transformer, eliminating the necessity for any external gate drive auxiliary bias supply or high-side bootstrap. This transfer dramatically simplifies the system design and reduces electromagnetic interference (EMI) through reduced total common-mode (CM) capacitance. Furthermore, the transfer allows the drive of a floating switch at any location in a switching power topology.

The chipsets are offered in a pair of 3mm x 3mm, 10-pin, dual-flat no-leads (DFN-10) surface-mount packages. Several protection features are integrated, including undervoltage lockout on primary and secondary bias rails, internal pulldown on IN and OUTPD pins, and a fast-response enable input/fault-output pin.

Features

Chipset transmits both PWM signal and bias power through a single external isolation transformer
- No high-side bootstrap
- No external secondary-side bias supply
50ns propagation delay (with recommended transformers)
Separate drive output pins pull-up (2.8Ω) and pull-down (1.0Ω)
Supply voltage 10.5V <V_DRV <13.2V
Enable pin with fast response

Undervoltage lockout on primary V_DRV and secondary V_SEC
Continuous ON capability - no need to recycle IN or recharge the bootstrap capacitor
CMTI > 100V/ns dv/dt immunity (with recommended transformers)
System creepage distance > 4mm or 8mm (with recommended transformers)

Applications

AC-DC and DC-DC converters, including totem-pole PFC, LLC half-/full-bridge, SR drive, multi-level converters, phase-shifted full-bridge, high-side cutoff switches
Industrial-including data center, transportation, robotics, audio