Introduction

As automobiles become more electrified and sophisticated, the power supply design required for in-vehicle ECUs is becoming increasingly complex year by year. With the development of ADAS, electric powertrains, and in-vehicle networks, it has become essential to stably supply and manage multiple voltage rails within the ECU.

​Power Management ICs (PMICs) are designed to efficiently and reliably manage these complex power supplies.
The PMIC integrates functions such as power conversion, voltage monitoring, and watchdog capabilities onto a single chip, playing a crucial role in the integrated management of the entire ECU's power system.

In recent years, driven by the increasing performance of automotive ECUs and the growing demand for functional safety, PMICs have become more than just power supply ICs; they are increasingly important devices that support the reliability and safety of ECUs.

This article will explain the following points:

• What is PMIC?
• Main functions of PMIC
• Why a PMIC is needed in an in-vehicle ECU
• Advantages of using PMIC
• Infineon's automotive PMIC solutions

What is PMIC?

A PMIC (Power Management IC) is a semiconductor used to generate, monitor, and control the power supply required for electronic systems.

By integrating multiple power supply functions into a single chip, the overall power management of the system is made more efficient. Typical PMICs integrate power generation functions using DC/DC converters and LDOs (linear regulators), as well as voltage monitoring, watchdog reset control, and an SPI interface.  This enables stable power supply and safe operation management for peripheral circuits such as MCUs and SoCs.

In particular, in automotive ECUs, where high reliability and functional safety must be ensured within a limited space, PMICs play a crucial role as core devices in power supply design.

Main functions of PMIC

A PMIC is a power management IC that integrates not only power generation but also system monitoring functions. Typical functions include the following:

However, there are cases where a PMIC cannot supply all the power, or where a more flexible power supply configuration is required. Infineon offers a wide range of automotive power supply devices, including standalone LDOs (OPTIREG ™ Linear) and DC/DC converters (OPTIREG ™ Switcher), in addition to PMICs.

Please also consider the discrete component configurations that are appropriate for your application.

Advantages of using PMIC

The main feature of a PMIC is that it integrates power generation and management into a single chip, but what are the actual advantages of adopting a PMIC in ECU design?

Supplemental information: What is a window watchdog?
A window watchdog is a safety feature that monitors whether a microcontroller is operating at the correct time.
A typical watchdog system detects an anomaly if the microcontroller does not send a "lives signal (kick signal)" within a certain time period.
However, this method may not be able to detect when the software malfunctions and sends signals at an abnormal frequency.

Therefore, in-vehicle systems use window watchdogs for more rigorous monitoring.
In a window watchdog, a specific time window is defined during which the microcontroller is allowed to send signals.
This window will be considered abnormal if it appears too early or too late.

This allows for the detection of software freezes, software malfunctions, timing anomalies, and other issues.
Because functional safety is crucial in automotive ECUs, many automotive PMICs and safety microcontrollers are equipped with a window watchdog.

What is Infineon's automotive PMIC?

Infineon offers the OPTIREG™ PMIC series for automotive applications. The lineup includes general-purpose PMICs for general use and application-specific PMICs specialized for ADAS, transmissions, and inverters.

We provide detailed information about the product specifications, intended applications, and block diagrams, so please take a look at our product introduction page.

Furthermore, these PMICs feature high-reliability designs for automotive applications, functional safety compliance, and optimal integration with automotive microcontrollers. In particular, when combined with Infineon's AURIX™ series of automotive microcontrollers, they enable efficient power supply design for ECUs.

Main application applications of automotive PMICs

Infineon's automotive PMICs are used in a wide range of automotive ECUs due to their efficient generation of multiple power supplies and integrated safety features. This section explains typical applications and the reasons for adopting PMICs.

In this way, PMICs support ECU design in each application from both a power management and safety function perspective.

Summary

As mentioned in this article, PMICs are semiconductors that play a central role in power management in automotive ECUs. By integrating multiple power functions onto a single chip, they simultaneously improve the efficiency of power design and the reliability of the system. In particular, the importance of PMICs is increasing in recent automotive systems due to factors such as the increased performance of ECUs, the increase in power rails, and the sophistication of functional safety requirements.

By adopting a PMIC, it becomes possible to reduce the number of components, simplify the design, improve safety through power monitoring and watchdog functions, and enable integrated power management through cooperation with the microcontroller, significantly contributing to improved design quality and development efficiency of automotive ECUs.

Infineon's TLF35585 series and other automotive PMICs are highly integrated and reliable power management solutions that meet these requirements and are used in a wide range of applications, including ADAS, EPS, BMS, and domain controllers. As automotive electronics continue to advance, PMICs are expected to further expand their role as an indispensable component in ECU design.

Inquiry / Quotation

If you have any questions or would like a quote regarding this article, please contact us using the form below.