1
ZHCU572–November 2018
TIDUED3 — http://www-s.ti.com/sc/techlit/TIDUED3
版权 © 2018, Texas Instruments Incorporated
汽车电动座椅参考设计
TI Designs
：：
TIDA-020008
汽汽车车电电动动座座椅椅参参考考设设计计
说说明明
该设计提供了用于使用双向和单向电机驱动器的电机驱
动 应用（如汽车电动座椅）的驱动和控制电路。它演示
了如何驱动具有小电路板尺寸、高度可靠性和完整诊断
功能的刷式直流电机。该设计说明了用于增加电机驱动
舒适性和便利性选项以及使用更智能的全功能器件替代
基于继电器的电路的解决方案。
资资源源
TIDA-020008 设计文件夹
DRV8703-Q1 产品文件夹
DRV8873-Q1 产品文件夹
TPS2H160-Q1 产品文件夹
TPS22810-Q1 产品文件夹
SN74LV4051A-Q1 产品文件夹
TLIN1029-Q1 产品文件夹
TPS7B82-Q1 产品文件夹
咨询我们的 E2E™ 专家
特特性性
• 用于直流电机的双向驱动器
– 刷式电机 A：高达 30A 峰值
– 刷式电机 B：高达 10A 峰值
• 用于腰托的单向驱动器
– BDC 泵电机
– 电磁阀
• 来自所有电机的多路复用电流感应信号
• 反向电池保护和负载突降保护
• 每个驱动电路的小电路板尺寸
应应用用
• 座椅位置和舒适模块
• 座椅位置和折叠模块
• 座椅舒适模块
该 TI 参考设计末尾的重要声明表述了授权使用、知识产权问题和其他重要的免责声明和信息。
System Description
www.ti.com.cn
2
ZHCU572–November 2018
TIDUED3 — http://www-s.ti.com/sc/techlit/TIDUED3
版权 © 2018, Texas Instruments Incorporated
汽车电动座椅参考设计
1 System Description
The TIDA-020008 reference design implements drive, control, and diagnostic circuits applicable to several
features found in automotive power seats. Three different drive topologies demonstrate how to design for
a variety of system requirements with a high degree of adjustability to match the wide range of automotive
body features found in a power seat (or similar applications).
• High-current (up to 30-A peak) bidirectional brushed DC (BDC) motor drive
• Medium-current (up to 10-A peak) bidirectional brushed DC motor drive
• Dual single-direction drive for actuators such as solenoids or unidirectional pumps or fans
The design also implements the ancillary functions needed for a power seat module, such as power
conditioning, network communications, and illumination control.
The design includes an example of a high-current bidirectional motor drive using a solid-state full-bridge
circuit. Based around the DRV8703-Q1 motor driver, this circuit includes all the components needed for
driving motors up to around 300 W of peak power (30 A at typical automotive battery voltages). It also
includes smart drive features IDRIVE and TDRIVE to facilitate tuning the motor operation for improved
efficiency and EMC performance. Diagnostic features monitor the motor current and state of the final drive
FETs to provide real-time feedback of the critical drive conditions. This high-current bidirectional drive is
intended for and tested with typical power seat motorized features such as seat positioning for forward
and back, up and down, and seat tilt.
The medium-current drive includes all the components needed for driving motors with up to 10 A of peak
current, using the single-chip DRV8873-Q1 motor driver. It includes register-programmable features to
adjust the off-time and slew rate of the drive stage to improve efficiency and EMC performance.
Diagnostic features monitor the motor current and state of the drive FETs to provide real-time feedback of
the critical drive conditions, including detection of faults such as supply undervoltage, charge pump
undervoltage, motor overcurrent, open load, and high-temperature thermal faults. This circuit is intended
for and tested with power seat features such as motorized headrest adjust or similar bidirectional
adjustments.
A dual-channel smart high-side switch implements the control and drive circuits for single-directional
motorized applications such as lumbar support inflation pumps and the associated solenoid valves with
spring return. The features of this circuit include an adjustable current limit to protect against short-to-
ground load faults, thermal shutdown, and protection against negative voltage spikes caused by inductive
loads.
An eight-channel multiplexer allows selecting any of several different signals to monitor with a single
microcontroller analog-to-digital converter (ADC), simplifying the MCU requirements while still providing
full diagnostic capabilities. A low-power mode is implemented to allow reducing the overall current from
the battery to a very low level during periods when adjustment of the seat is not active.
A thermally-protected load switch provides a simple LED drive circuit for turning on an onboard LED to
illuminate under the seat; alternately an off-board LED can be driven by the same circuit. A standard
LaunchPad™ interface to an off-board microcontroller provides common signals for monitoring and control
of the drives. The entire design is protected against reverse-battery conditions and load-dump conditions,
and includes a LIN transceiver for communication with a central Body Control Module (BCM).
www.ti.com.cn
System Description
3
ZHCU572–November 2018
TIDUED3 — http://www-s.ti.com/sc/techlit/TIDUED3
版权 © 2018, Texas Instruments Incorporated
汽车电动座椅参考设计
1.1 Key System Specifications
表表 1. Key System Specifications
PARAMETER SPECIFICATIONS DETAILS
Drive A motor type Bidirectional brushed DC motor 节 2.4.1
Drive A peak current 30 A
Drive B motor type Bidirectional brushed DC motor 节 2.4.2
Drive B peak current 10 A
Drive C motor type Unidirectional brushed DC motor 节 2.4.3
Drive C peak current 4 A
Drive D motor type DC solenoid valve 节 2.4.3
Operating supply voltage range 6 V to 18 V
Survivable supply voltage range –20 V to 40 V
Peak total drive current 40 A
Sleep-mode quiescent current < 100 µA
Position feedback compatibility Hall effect sensor inputs or ripple count 节 2.4.7
Current sense Selectable by multiplexer
Microcontroller interface LaunchPad 2 × 20-pin connectors 节 2.4.8
Network connectivity LIN Transceiver 节 2.3.5
Illumination circuit Thermally-protected LED switch
Full-Bridge Drivers
DRV8703-Q1
Gate Driver
Seat Tilt
Headrest Up/Down
Lumbar Pump
Lumbar Drivers
TPS2H160-Q1
Dual High Side Switch
Light Driver
TPS22810-Q1
Load Switch
Position Feedback
Position Sensor
MCU
MSP430
/DXQFK3DGŒ
MCU
Car
Battery
Lumbar Valve
Seat Light
Seat
Body
Control
Module
(BCM)
Communication Interface
TLIN1029-Q1
LIN Transceiver
SN74LV4051A-Q1
Analog MUX
Power Supply
TPS7B82-Q1
LDO Regulator
Reverse Battery
Protection
HMI Switches and
Switch Interface
DRV8873-Q1
Motor Driver
TIDA-020008-Q1 Board
M
M
M
System Overview
www.ti.com.cn
4
ZHCU572–November 2018
TIDUED3 — http://www-s.ti.com/sc/techlit/TIDUED3
版权 © 2018, Texas Instruments Incorporated
汽车电动座椅参考设计
2 System Overview
2.1 Block Diagram
图图 1. TIDA-020008 Block Diagram
2.2 Design Considerations
To simplify this reference design and make the design more adaptable to a variety of microcontroller units
(MCUs), the board is implemented in the BoosterPack™ format. This board format has a simple connector
interface to the external LaunchPad MCU board, which allows this reference design to be evaluated with a
wide selection of MCUs. The LaunchPad plus BoosterPack implementation also has the advantage that
code development and design testing are facilitated with existing tools such as Code Composer Studio™
or Energia, thus speeding up optimization of the design for any specific operating conditions. While the
BoosterPack format does allow flexibility in using different MCU boards, the format also creates
constraints on the size and layout of the board. In a production version of this design, the MCU would
likely be installed on the same board with the chips and other components with a significant reduction in
board size.
For ease of testing, the board includes five control switches that would not be present in a production
power seat module design. These switches provide for user inputs without the need for an external
network or computer.
Another consideration is selecting the passive components. In general, components are selected based
on the performance requirements of the expected applications. Where practical, components with
automotive ratings are selected. For active components, the components selected are AEC-Q100 qualified
to either temperature grade 0 or temperature grade 1.
www.ti.com.cn
System Overview
5
ZHCU572–November 2018
TIDUED3 — http://www-s.ti.com/sc/techlit/TIDUED3
版权 © 2018, Texas Instruments Incorporated
汽车电动座椅参考设计
Capacitors are generally X7R grade (−55°C to +125°C) or higher with size and value selected for the
expected extremes of operation conditions. The voltage rating of the capacitors must be greater than the
maximum voltage they could experience and two times the typical operating voltage to avoid DC bias
effects. The amount of output capacitance used depends on output ripple and transient response
requirements, and many equations and tools are available online to help estimate these values.
2.3 Highlighted Products
2.3.1 DRV8703-Q1 Automotive H-Bridge Gate Driver
The DRV8703-Q1 is a single H-bridge gate drivers that use four external N-channel MOSFETs targeted to
drive a bidirectional brushed-DC motor.
A PH/EN, independent H-Bridge, or PWM interface allows simple interfacing to controller circuits. An
internal sense amplifier provides adjustable current control. Integrated Charge-Pump allows for 100% duty
cycle support and can be used to drive external reverse battery switch.
Independent half-bridge mode allows sharing of half bridges to control multiple DC motors sequentially in
a cost-efficient way. The gate driver includes circuitry to regulate the winding current using fixed off-time
PWM current chopping.
The DRV8703-Q1 includes Smart Gate Drive technology to remove the need for any external gate
components (resistors and Zener diodes) while fully protecting the external FETs. The Smart Gate Drive
architecture optimizes dead time to avoid any shoot-through conditions, provides flexibility in reducing
electromagnetic interference (EMI) with programmable slew-rate control and protects against any gate-
short conditions. Additionally, active and passive pulldowns are included to prevent any dv/dt gate turnon.
A low-power sleep mode is provided which shuts down internal circuitry to achieve a very-low quiescent-
current draw. The device can be used in a very compact design because of its small 5 mm × 5 mm
package with few external components.
2.3.2 DRV8873-Q1 Automotive H-Bridge Motor Driver
The DRV8873-Q1 device is an integrated driver IC for driving a brushed DC motor in automotive
applications. Two logic inputs control the H-bridge driver, which consists of four N-channel MOSFETs that
drive motors bidirectionally with up to 10-A peak current. The device operates from a single power supply
and supports a wide input supply range from 4.5 V to 38 V.
A PH/EN or PWM interface allows simple interfacing to controller circuits. Alternatively, independent half-
bridge control is available to drive two solenoid loads.
A current mirror allows the controller to monitor the load current. This mirror approximates the current
through the high-side FETs, and does not require a high-power resistor for sensing the current.
A low-power sleep mode is provided to achieve very-low quiescent current draw by shutting down much of
the internal circuitry. Internal protection functions are provided for undervoltage lockout, charge pump
faults, overcurrent protection, short-circuit protection, open-load detection, and overtemperature. Fault
conditions are indicated on an nFAULT pin and through the SPI registers.
2.3.3 TPS2H160-Q1 Dual-channel Smart High-side Switch
The TPS2H160-Q1 is a fully-protected dual-channel smart high-side switch, with integrated 160-mΩ
NMOS power FETs.
评论0