Infineon's New PMIC Integrates Safety and Resolver Circuits
Infineon has launched the TLE9744QK power management IC, a single chip that consolidates power rails, resolver excitation, and a safety engine for electric
Infineon has introduced a new power management integrated circuit (PMIC) designed specifically for the high-voltage traction inverters in electric and hybrid vehicles. The OPTIREG TLE9744QK combines an inverter's multiple supply rails, its resolver excitation circuit, and a dedicated safety logic block into one device.
Typically, an inverter's electronic control unit requires several isolated power rails for its microcontroller, communication modules, and sensors. These are usually built from discrete components. Infineon states that integrating these functions into its new PMIC can save up to 70% of the board area those discrete parts would occupy. The component count is also reduced.
Integrated Resolver Excitation
A key function of a traction inverter is to read the precise position of an electric motor's rotor, which is often done using a component called a resolver. This resolver requires an AC excitation signal. Normally, a separate driver circuit generates this signal. The TLE9744QK generates this excitation on-chip, eliminating the need for that external driver and its associated monitoring circuitry on the circuit board.
Technical Specifications and Features
The chip's architecture includes two buck/boost pre-regulators that feed linear post-regulators to create the necessary voltage rails for the microcontroller, communications, and reference circuits. It also incorporates two tracker regulators, six analog inputs, five digital inputs, and four digital outputs.
Key operational specifications for the device are listed below.
| Specification | Value |
|---|---|
| Quiescent Current | 50 µA |
| Operating Voltage Range | 4 V to 36 V |
| Operating Temperature Range | -40° C to 150° C |
| Package | PG-LQFP-64 |
The PMIC includes built-in functional and window watchdogs. It can also supply power to sensors located off the main board. Infineon lists its TRAVEO T1G and AURIX TC2x, TC3x, and TC4x microcontroller families as compatible with the new IC.
Dedicated Safety Logic Path
A major feature is the Integrated Safety Logic (ISL) block. This operates as a second, independent safety path within the system. It continuously monitors phase currents, DC-link voltage, and the health of the main microcontroller and gate drivers. If the primary microcontroller malfunctions, the ISL can determine and enforce a safe operating state for the inverter.
To ensure this safety path remains active even during a power failure, the chip has a redundant supply input. This design means a fault on the main low-voltage supply rail will not disable the safety logic. Infineon says the architecture fulfills the highest Automotive Safety Integrity Level, ASIL-D, and was developed according to the ISO 26262 functional safety standard.
Availability and Longevity
According to the source, Infineon, samples, evaluation boards, reference designs, documentation, software, and development tools for the TLE9744QK are available on request. The product page indicates the part is in stock with unit pricing listed. The company also states the component is planned to remain in production and available for purchase until at least the year 2038.
