Allegro AHV85000/40 IC Pair Brings Isolated Gate Drive And Bias Power Via One Transformer
Allegro MicroSystems has introduced a two-chip isolated gate-driver “chipset” that pushes both the PWM control signal and the gate-bias power across the isolation barrier using a single external transformer, aiming to cut BOM and free up layout options in high-voltage power stages. The pair is the AHV85000 (primary-side transmitter) and AHV85040 (secondary-side receiver), positioned for high-efficiency systems such as solar inverters, EV charging and energy storage, plus data-centre power supplies.
What the isolated gate driver pair actually changes
Instead of the usual split between an isolated signal path and a separate isolated DC/DC bias supply on the secondary side, the AHV85000/40 approach sends both through the same external transformer. In Allegro’s description, that removes the need for a high-side bootstrap and eliminates an external secondary-side bias supply, while letting designers choose and place the transformer to suit creepage/clearance, mechanical constraints, and EMI strategy. For designers who’ve been boxed in by fixed transformer placement inside an isolated driver package, that “external transformer, your choice” angle is the point.
Key specs called out
Distributor material highlights a propagation delay of about 50 ns when used with Allegro’s recommended transformers, separate pull-up and pull-down output pins (quoted as 2.8 Ω pull-up and 1.0 Ω pull-down), and a driver supply range stated as 10.5 V < VDRV < 13.2 V. As always, real-world results hinge on transformer choice, layout, and the gate network around the switch, but the pitch is clearly about predictable switching with fewer support parts.
Context: why “isolated gate driver” integration keeps trending
Wide-bandgap power stages keep raising the bar for dv/dt immunity, switching-speed control, and clean isolation practices, and vendors are responding by integrating more of the “boring but necessary” support circuitry around the switch. If you want a recent automotive-angled example of the broader isolated gate driver trend, see eeNews Europe’s coverage of ST’s ASIL-D isolated gate driver launch. That earlier design takes a different integration route, but it underlines the same market pressure: simplify isolation and tighten switching behaviour without exploding the parts count.
For more detail on Allegro’s positioning of the AHV85000/40 pair and its “Power-Thru” messaging, Signal Integrity Journal’s write-up is a useful starting point: Power-Thru combo chip overview.
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