ST AEK-MOT-WINH92 User Manual

Getting started with the AEK-MOT-WINH92 window lift DC board driver based on
Introduction
Most modern vehicles feature electric window lifters controlled using buttons in door control panels.
These electric window lifters are fitted with convenience functions that include automatic full up or down of the window lifter
when the switch is pressed once, link of the window lifter to the central locking so that, when the car is locked, all windows close
automatically, and safety functions, such as antipinch.
The antipinch safety function senses if a motor is running against an obstacle and prevents any injuries to people/objects or
damage to the motor itself. When a resistance is registered during closing, the movement of the window is reversed
automatically so that it reopens immediately.
The antipinch sensing is usually performed by current monitoring, Hall sensors or a combination of both. This safety system
checks continuously the variation of the current and the variation of the velocity. Both are compared with a threshold and if they
simultaneously report the presence of an obstacle, the motor is blocked.
Our AEK-MOT-WINH92 evaluation board key objective is to drive a DC motor for car window lifters, ensuring high safety levels.
This board perfectly fits in the automotive market trend, which goes towards the evolution of the window lift application, offering
a new antipinch mechanism without leveraging on motor encoders but exploiting the board three different types of current
sensing (in-line, low-side, and high-side).
The board can be configured to work with a single H-bridge for a bidirectional DC motor or two independent half-bridges for two
unidirectional DC motors.
Thanks to its compact size, the board can be connected to any microcontroller easily, exploiting separate and dedicated
connectors for SPI communication, current sensing, and basic motor commands interface with fault detection capabilities.
Another key feature is the adjustable gain for antipinch and for fulfilling any of the car window operative conditions (the current
range levels could change when opening the window with adverse weather conditions, for example in case of ice).
The board also offers three diagnostic features to detect potential short-to-ground, short-to-battery, and open load conditions
when the device is in the off state.
In case of failures, the DIAG pin alerts the external MCU, ensuring a prompt intervention in case of open-load, short-to-ground,
and short-to-battery, thermal warning and overtemperature shutdown, under/overvoltage and overcurrent protection. For system
debugging during the development phase, a fail-safe button was added to the board layout.
To allow the board robust protection and prevent damage due to the inversion of the power supply polarity, reverse polarity
protection has been implemented.
Four external MOSFETs allow current flowing up to 50 A, in line with the board power dissipation capabilities.
The board design is based on the L99H92 H-bridge gate driver for automotive applications, which features flexible current
sensing to offer different tools for advanced antipinching algorithm development. For systems requiring a higher safety level, you
can enable a watchdog with a configurable time window.
Warning: The AEK-MOT-WINH92
laboratory use only.
UM3324 - Rev 1 - March 2024
For further information contact your local STMicroelectronics sales office.
the L99H92 gate driver and an external MCU
evaluation board has not to be used in a vehicle as it is designed for R&D
UM3324
User manual
www.st.com