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[原创] ST L9945八路12V和24V系统全配置高-低边MOSFET预驱动解决方案

关键词:汽车电子 12V系统 24V系统 MOSFET驱动器 L9945

时间:2019-05-30 10:41:23       来源:中电网

ST公司的L9945是八路MOSFET预驱动器,可配置成用于低边,高边,峰值和保持以及H桥负载的控制,设计用于12V(客车)和24V(商用车)电池系统.所有输出是PWM控制的,其中6个输出能安全驱动相关载荷,一个能激励需要专用使能引脚(EN6)的相关载荷.L9945提供控制两个单独H桥的功能,还能驱动多达两个需要”峰值保持”控制的负载.每个输出提供全部的诊断信息如对电池短路,对地短路和负载开路.而每个输出状态能不断通过专用SPI寄存器进行监测.器件满足AEC-Q100规范,3.3V和5V逻辑兼容I/O,工作电池电压3.8V到36V,工作的VDD电压4.5V-5.5V,L9945中的10位ADC通过SPI对电池和芯片温度进行测量.主要用在汽车电子.本文介绍了L9945主要特性,框图以及评估板EVAL-L9945及其应用框图,配置框图,电路图,材料清单和PCB设计图.

The L9945 is an 8-channel MOSFET pre-driver configurable for low-side, high-side, peak and hold and H-Bridge load control. It is designed to comply with the requirements of 12 V (passenger vehicle) and 24 V (commercial vehicle) battery systems.

All outputs can be PWM controlled. Six outputs are capable of driving safety relevant loads. One output can be dedicated to the actuation of safety relevant loads requiring a dedicated enable pin (EN6).

The device offers the possibility of controlling two independent H-Bridges.
The device can also drive up to two loads requiring "peak & hold" control strategy.
The driver outputs are protected against short circuit condition.
The device protects the external MOS in case of an overcurrent event.
Each output provides full diagnostic information such as short to battery, short to ground and open-load. Each output status can be constantly monitored through dedicated SPI registers.
The voltage slew rate of the external transistors 1-8 is controlled during turn ON and turn OFF in order to improve EMI behavior.
A double, redundant, external disable source is available through DIS and NDIS pins in order to improve safety.
The device is configurable via SPI through a 32-bit protocol.

L9945主要特性:

AEC-Q100 qualified
12 V and 24 V battery systems compliance
3.3 V and 5 V logic compatible I/O
8-channel configurable MOSFET pre-driver
High-side (N-channel and P-channel MOS)
Low-side (N-channel MOS)
H-bridge (up to 2 H-bridge)
Peak & Hold (2 loads)
Operating battery supply voltage 3.8 V to 36 V
Operating VDD supply voltage 4.5 V to 5.5 V
All device pins, except the ground pins, withstand at least 40 V
Programmable gate charge/discharge currents for improving EMI behavior
Individual diagnosis for:
Short circuit to battery
Open load
Short circuit to ground
Highly flexible overcurrent sensing implementation
Possibility of monitoring external MOS drain to source voltage
Possibility of monitoring voltage on external shunt resistor
64 programmable overcurrent thresholds independent for each channel
Ultra-fast output shutdown in case of overcurrent
Current limitation for H-Bridge configuration
32-bit SPI protocol available for configuration and diagnostics
Failures latched even if they occur during diagnostics reading
Daisy chain operation
SDO protected against overvoltage
Safety features
Fast switch off redundant output disable through two external pins
Built InSelf Test (BIST) for logic operation
Hardware Self Check (HWSC) for VDD5 overvoltage comparator
Configurable Communication Check (CC) watchdog timer available
Disable feedback through bi-directional pin
Highly redundant output monitoring through dedicated SPI registers
10-bit ADC for battery and die temperature measurements available through SPI VDD5 monitoring for over/under voltage
VPS (battery) monitoring for under voltage

图1.L9945框图(1)

图2.L9945框图(2)

评估板EVAL-L9945

The EVAL-L9945 is an evaluation board designed to provide the user with a set of tools for the evaluation of the product L9945, a configurable HS/LS driver for automotive applications. The board provides all the main input/output capabilities needed to drive all the supported loads in addition to diagnostic functionalities.

The EVAL- L9945 is an evaluation board designed to evaluate L9945, a smart power device designed by STMicroelectronics in advanced BCD technology.

图3.评估板EVAL-L9945应用框图

图4.评估板EVAL-L9945外形图

图5.评估板EVAL-L9945电路图(1)

图6.评估板EVAL-L9945电路图(2)

图7.评估板EVAL-L9945电路图(3)

图8.评估板EVAL-L9945电路图(4)
评估板EVAL-L9945材料清单:



图9.评估板EVAL-L9945配置框图

图10.评估板EVAL-L9945 PCB设计图:正面布局

图11.评估板EVAL-L9945 PCB设计图:背面布局

图12.评估板EVAL-L9945正面视图

图13.评估板EVAL-L9945正面主要元件和连接器图
详情请见:
https://www.st.com/content/ccc/resource/technical/document/user_manual/group1/d0/b0/26/83/aa/3f/45
/61/DM00602473/files/DM00602473.pdf/jcr:content/translations/en.DM00602473.pdf

https://www.st.com/content/ccc/resource/technical/layouts_and_diagrams/schematic_pack
/group1/4c/fd/da/d6/b4/48/40/dd/EVAL-L9945_SCHEMATIC/files/EVAL-L9945_Schematic.pdf/jcr:content/translations/en.EVAL-L9945_Schematic.pdf

以及https://www.st.com/content/ccc/resource/technical/document/bill_of_materials/group0/47/23/b4
/13/a6/4e/44/8d/EVAL-L9945_BOM/files/EVAL-L9945-BOM.pdf/jcr:content/translations/en.EVAL-L9945-BOM.pdf

en.DM00602473.pdf
en.EVAL-L9945-BOM.pdf
en.EVAL-L9945_Schematic.pdf

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