Infineon TLE9744QK PMIC Combines Resolver Excitation and ASIL-D Safety Logic for EV Inverters

Infineon has introduced the OPTIREG TLE9744QK, a power management IC for the high-voltage traction inverters used in electric and hybrid vehicles. The part folds an inverter's supply rails, its resolver excitation circuit and a dedicated safety engine into a single device.

An inverter ECU needs several isolated rails for its microcontroller, communication modules and sensors, and those rails are normally assembled from discrete components. Infineon puts the board-area saving at up to 70% for the devices the single chip replaces, and says component count falls along with it.

A traction inverter reads rotor position from a resolver, which needs an AC excitation signal on its primary winding and returns sine and cosine voltages that resolve to a rotor angle. That excitation is normally generated by a separate driver, so producing it on-chip takes the driver and its monitoring circuitry off the board.

The product page lists two buck/boost pre-regulators feeding linear post-regulators for the microcontroller, communications and reference rails, along with two trackers, six analog inputs, five digital inputs and four digital outputs. Quiescent current is 50 µA, the operating voltage range runs from 4 V to 36 V and the operating temperature range covers -40° C to 150° C, in a PG-LQFP-64 package. Functional and window watchdogs are built in. The part can also supply sensors mounted off the board, and TRAVEO T1G and AURIX TC2x, TC3x and TC4x are listed as compatible microcontrollers.

The Integrated Safety Logic (ISL) block runs as a second, independent safety path. It supervises phase currents, DC-link voltage and the health of the microcontroller and gate drivers, and it can determine and enforce a safe state if the main microcontroller stops working correctly. A redundant supply input keeps the ISL running if the main low-voltage supply fails, so a fault on that rail does not take the safety path down with it. Infineon says the architecture fulfills ASIL-D, developed according to ISO 26262.

Samples, evaluation boards, reference designs, documentation, software and tools are available on request, and the product page lists the part in stock with unit pricing. Infineon also lists the part as planned to remain available until at least 2038.

Source: Infineon