ST公司的L99SM81V是汽車級的綜合驅動器,用于雙極兩相步進馬達,該馬達具有可編幅度的電流控制微步進功能.器件具有5V電壓穩壓器以便給外接傳感器供電.L99SM81V集成的串行外設接口(SPI)使得可調整器件參數,控制所有的工作模式和讀出診斷信息.數字I/O也可選擇以用于更靈活和更可靠的應用控制.器件滿足AEC-Q100資質,步進馬達驅動器電流高達1.35A,可編程的步進模式包括全步進,半步進,迷你步進,1/8微步進,1/16微步進.電流調整回路有等效的10位分辨率.器件具有兩個4位可編滿刻度電流放大:一個用于RUN,另一個用于HOLD模式.6為DAC用于基準電流產生.PWM頻率搖擺可降低EM能量.器件具有輸出保護和診斷(開路負載,對電池短路和對地短路),集成的ADC用于線圈電壓檢測和失速檢測,5V低壓降穩壓器用于短路保護,待機模式具有非常低的電流消耗(典型值為10 μA).熱告警和關斷功能.主要用在汽車電子的雙極2相步進馬達驅動器如自適應前燈系統或平視顯示器投映儀.本文介紹了L99SM81V主要特性,框圖,步進馬達驅動器應用框圖和評估板AEK-MOT-SM81M1主要特性,步進馬達應用框圖,電路圖,材料清單.

 The L99SM81V is an automotive grade integrated driver for bipolar two-phase stepper motors capable of current controlled micro-stepping with programmable amplitude. The device features a 5 V voltage regulator to supply external sensors.

The integrated Serial Peripheral Interface (SPI) makes it possible to adjust device parameters, control all operating modes and read out diagnostic information. Digital I/Os are also optionally usable for more flexible and reliable application control.

L99SM81V主要特性:

· AEC-Q100 qualified

· Stepper motor driver with up to 1.35 A current capability

· Programmable Step mode:

- Full step, Half step, Mini step, 1/8 Micro step, 1/16 Micro step

· Current regulation by integrated PWM control with fully integrated current sensing

· Equivalent 10 bit resolution on current regulation loop:

- Two 4-bit programmable full scale current amplitudes: one for RUN and one for HOLD mode

- 6-bit DAC for reference current generation (whatever programmed full scale amplitude)

· 4 programmable decay modes:

- Slow-mode, mixed-mode and 2x automatically selected decay-modes

· 3x programmable inputs for direct control of step clock, direction, hold and step modes

· 1x programmable analog output for Tj measurement or band-gap reference

· 2x programmable digital outputs for internally generated PWM ON duty cycles,error signals, coils voltage measurement synchronization signals

· Programmable MOSFETs switching speed: four options for EMC and power dissipation trade-off optimization

· PWM frequency wobbling for reduction of conducted EM energy

· Outputs protection and diagnosis (open load, short to battery, short to GND)

· Integrated ADC for coil voltage measurement and stall detection

· 5 V low drop voltage regulator short-circuit protected

· Very low current consumption in standby mode (typ. 10 μA)

· Thermal warning and shutdown

· ST SPI 4.1 interface for control and diagnostics

L99SM81V應用:

Bipolar 2 phase stepper motor driver for automotive applications like adaptive front light systems or projectors for head-up displaying

圖1.L99SM81V框圖(QFN40L)

圖2.L99SM81V框圖(PowerSSO-36)

圖3.L99SM81V步進馬達驅動器應用框圖

評估板AEK-MOT-SM81M1

The AEK-MOT-SM81M1 evaluation board is designed to drive a bipolar stepper

motor in micro-stepping mode, with coil voltage monitoring for stall detection.

This application board features the automotive-grade L99SM81V stepper motordriver with embedded power MOSFETs and a comprehensive set of I/Os for MCUcontrol and feedback signaling using SPI communication through a 12-pin maleconnector or two 5-pin connectors on the board.

The board is developed as part of the AutoDevKit initiative, and evaluation firmwareis available for suitable microcontrollers such as the automotive-grade SPC5 seriesMCU on the AEK-MCU-C4MLIT1 control board.

The AEK-MOT-SM81M1 board targets automotive applications such as adaptive front lighting systems and HUDprojectors, with stepping resolution ranging from 4 full steps to 64 micro steps for the finest possible positionalcontrol.

The L99SM81V driver logically manages timers, counters, reference tables and mode or status registers that areread or set by the external microcontroller to drive the two coil phases of a bipolar stepper motor, with separateRUN and HOLD profiles for moving the rotor or keeping it stationary.

Apart from supply voltage and driver current diagnostics, the driver also monitors the output voltages across thephase terminals in order to detect and flag critical motor stall events that can compromise motor operation andcontrol.

評估板AEK-MOT-SM81M1主要特性:

• Board functionality based on L99SM81V programmable stepper motor driver forautomotive applications:

–with micro-stepping and hold functions

– BEMF monitoring for stall detection

–programmable configuration via SPI

– 5 V internal linear voltage regulator (output available on board connector)

• Board reverse battery protection with STD95N4F3 MOSFET, which can besubstituted with two optionally mounted diodes and a jumper

• Input operating voltage range from 6 V to 28 V

• Output current up to 1.35 A

• Board size: 65 mm length x 81 mm width x 11 mm maximum component height

• WEEE and RoHS compliant

• All ST components are qualified Automotive grade

• Part of the AutoDevKit™ initiative

• Applications: automotive bipolar stepper motor

圖4.評估板AEK-MOT-SM81M1外形圖

圖5.汽車步進馬達應用框圖

圖6.評估板AEK-MOT-SM81M1電路圖

評估板AEK-MOT-SM81M1材料清單: