As part of the efforts to make their vehicles more environmentally friendly, carmakers have increasingly been switching from hydraulic steering assist systems to electric power steering (EPS) using electric motors in order to reduce weight and boost fuel efficiency. In recent years, there has been a trend toward linking functions that assist the driver in operating the vehicle to the EPS system, for example by providing continuously variable steering gear ratio adjustment according to the running speed and steering angle, in addition to simple power shift functionality. This creates demand for microcontrollers (MCUs) capable of supporting sophisticated motor control with features such as high-performance CPU, large memory capacity, dedicated timer units, high-speed, high-precision A/D converters, and interfaces for communicating with other control units. In addition, the ISO 26262 functional safety standard for the automotive field was released in 2011 amid rising concerns over vehicle safety.

Systems that require the highest level of safety, such as the steering and brakes, typically require compliance with ASIL-D,* the highest safety level. This has led to a demand for MCUs that incorporate safety mechanisms such as redundant cores.

Renesas supplies optimized solutions to support system advances, based on technology such as high-performance lock step dual CPU cores.

*ASIL: Automotive Safety Integrity Level.
ASIL-D is the highest Automotive Safety Integrity Level.

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Electric Power Steering Block Diagram

Related Products

Microcontrollers

Recommended
Product
ROM
(Bytes)
RAM
(Bytes)
Operating
Frequency
(MHz)
Package
(Pin Count)
Features
RH850/P1H-C 4M, 8M LRAM: 2x64K
GRAM: 960K
160, 240
2×DCLS*1
292, 404 FBGA ICU-M, ECM, ECC, 4xCAN, 4xFlexRay, Ethernet, 2xADC (40×12-bit)
RH850/P1M 512K, 1M, 2M LRAM: 64K, 128K
Trace RAM: 32K
ERAM: 8K, 32K
160
DCLS*1
100, 144 LFQFP ICU-S, ECM, ECC, 3xCAN, 2xFlexRay, 2xADC (12×12-bit)
RH850/P1M-E 1M, 2M LRAM: 128K
GRAM: 64K
Trace RAM: 32K
ERAM: 8K, 32K
160
DCLS*1
100, 144 LFQFP ICU-S, ECM, ECC, 3xCANFD, 2xFlexRay, 2xADC (12×12-bit)
RH850/P1M-C 2M LRAM: 128K
GRAM: 320K
120, 160, 240
DCLS*1
144 LQFP,
292 FBGA
ICU-M, ECM, ECC, CANx3ch, FlexRayx2ch, Ethernet, 2xADC (24×12-bit)
RH850/P1L-C 512K, 1M LRAM:64K, 100K
Trace RAM:32K
ERAM: 8K
120
DCLS*1
80, 100, 144 LFQFP ICU-S, ECM, ECC, 2xCAN, ADC (20x12-bit )

*1 DCLS: Dual Core Lock Step

Analog/Power Devices

Analog/Power Device Recommended
Product
Features
EPS
Motor Drive MOSFET
for 3-phase Brushless Motors
NP180N04TUK 40V/1.05mΩ, TO-263 7-pin
NP179N04TUK 40V/1.25mΩ, TO-263-7pin
NP109N04PUK 40V/1.75mΩ, TO-263
NP110N04PUK 40V/1.4mΩ, TO-263
EPS
Motor Drive MOSFET for H-bridge Motors
NP89N04PUK 40V/2.95mΩ, TO-263
NP89N04PDK 40V/2.95mΩ, TO-263
NP60N04PDK 40V/3.95mΩ, TO-263
NP90N04VUK 40V/2.8mΩ, TO-252
NP60N04NUK 40V/4.8mΩ, 8pin HSON
Brake System
MOSFET for Failsafe Switches
RJE0603JPE -60V/15mΩ, thermal FET
Power Management IC RAA270005KFP Ideal power solution for RH850/P1x(with Built in voltage regulator for MCU’s core). Integrated fault diagnosis and monitor functions. Support cranking operation.
Op-Amp READ2351JSP Full range input/output, low power consumption
READ2352JSP Full range input/output, high slew rate
UPC1251/UPC451 Low power consumption
UPC842/UPC844 High slew rate
Comparator UPC277/UPC177 Low power consumption

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