DRV5055-5057EVM

User's Guide SLYU046 – January 2019 DRV5055-5057EVM This user’s guide describes the characteristics, operation, and use of the DRV5055, DRV5056, and DRV5057 (DRV505x) evaluation module (EVM). This EVM is designed to evaluate the performance of the DRV505x ratiometric, linear, Hall effect sensors. Throughout this document, the terms evaluation board, evaluation module, and EVM are synonymous with the DRV5055-5057EVM. This document includes a schematic, reference printed circuit board (PCB) layouts, and a complete bill of materials (BOM). SLYU046 – January 2019 Submit Documentation Feedback DRV5055-5057EVM Copyright © 2019, Texas Instruments Incorporated 1 www.ti.com 1 2 3 4 Contents Overview ...................................................................................................................... Operation ..................................................................................................................... Hardware...................................................................................................................... Schematics, PCB Layout, and Bill of Materials .......................................................................... 3 5 6 9 List of Figures 1 Microcontroller Source Code Operation .................................................................................. 6 2 Gain Variants A1 to A4 .................................................................................................... 10 3 LCD, Microcontroller and Switch ......................................................................................... 11 4 Push-Button, Slider Switch, and Programming User Inputs .......................................................... 12 5 LED and Indicators, Slider Switch Status Reader, and DRV5057 Multiplexer 6 7 8 9 10 .................................... Supply Input and Power Conditioning ................................................................................... Top Overlay ................................................................................................................. Top Layer ................................................................................................................... Bottom Overlay ............................................................................................................. Bottom Layer ................................................................................................................ 13 14 15 15 15 15 List of Tables 1 DRV505x Device Summary ................................................................................................ 3 2 Kit Contents 3 Related Documentation ..................................................................................................... 4 4 Bill of Materials .................................................................................................................. ............................................................................................................. 3 16 Trademarks All trademarks are the property of their respective owners. 2 DRV5055-5057EVM SLYU046 – January 2019 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Overview www.ti.com 1 Overview The DRV505x family of linear Hall effect sensors sense magnetic fields ranging from 19 mT to 176 mT full scale, depending on device and supply voltage. For each device, four gains are available. These devices operate from a single 3-V to 5.5-V power supply, drawing a maximum of 10 mA of supply current. These devices are currently available in a 3-pin SOT-23 or 3-pin TO-92 package. This EVM uses a 3.3-V supply, and Table 1 lists the gains at this voltage for each device. Table 1. DRV505x Device Summary 1.1 Product Gain at 3.3V VCC DRV5055A1 60 mV/mT DRV5055A2 30 mV/mT DRV5055A3 15 mV/mT DRV5055A4 7.5 mV/mT DRV5056A1 120 mV/mT DRV5056A2 60 mV/mT DRV5056A3 30 mV/mT DRV5056A4 15 mV/mT DRV5057A1 1.2 %D/mT DRV5057A2 0.6 %D/mT DRV5057A3 0.3 %D/mT DRV5057A4 0.15 %D/mT Kit Contents Table 2 lists the contents of the DRV5055-5057EVM kit. Contact the nearest Texas Instruments Product Information Center if any component is missing. Table 2. Kit Contents Item Quantity DRV5055-5057EVM test board 1 Cylindrical magnet 1 USB cable 1 SLYU046 – January 2019 Submit Documentation Feedback DRV5055-5057EVM Copyright © 2019, Texas Instruments Incorporated 3 Overview 1.2 www.ti.com Related Documentation From Texas Instruments This user's guide is available from the TI website under literature number SLYU046. Any letter appended to the literature number corresponds to the document revision that is current at the time of the writing of this document. Newer revisions are available from www.ti.com or the Texas Instruments' Literature Response Center at (800) 477-8924 or the Product Information Center at (972) 644-5580. When ordering, identify the document by both title and literature number. Table 3 lists documentation related to the DRV5055-5057EVM. Click the links in Table 3 for further information on the DRV505x. The device name links to the product web folder on www.ti.com. The literature number links to the document PDF. Table 3. Related Documentation 4 Document Title Document Literature Number DRV5055 data sheet SBAS640 DRV5055-Q1 data sheet SBAS639 DRV5056 data sheet SBAS644 DRV5056-Q1 data sheet SBAS643 DRV5057 data sheet SBAS646 SN74LVC1G17 data sheet SCES351 TCA9535 data sheet SCPS201 LP5907 data sheet SNVS798 TS5A23159 data sheet SCDS201 DRV5055-5057EVM SLYU046 – January 2019 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Operation www.ti.com 2 Operation 2.1 Quick Start Setup The following instructions describe how to set up and use the DRV5055-5057EVM. Step 1. Insert the USB cable into the EVM onboard USB receptacle. Step 2. For proper calibration, make certain that there are no magnets within a few feet of the EVM when the EVM powers up. Step 3. Plug the USB cable into any USB power adapter (for example, laptop, desktop, power bank, and so on). LED D13 on the far bottom right of the board indicates the board is powered, calibrated, and is taking sample measurements from the DRV5055A1 (default EVM startup device). 2.2 Measurements The DRV5055-5057EVM measures a magnetic field with multiple devices and the respective gain variants. Push-button S1 selects the different gain variants of the DRV505x devices. The devices are arranged such that gain variants increase sequentially from right to left, and the device families (DRV505x) are also arranged in an increasing order from right to left. The LCD displays the measurement corresponding to the selected device. The measurement format is adjusted by the slide switch labeled Display Mode (K1). Step 1. Click the Device Select Switch until an LED indicates the device of interest is selected. Step 2. Adjust the Display Mode slide switch to the measurement format of interest. Voltage mode (labeled V) is blank for the DRV5057 devices. Step 3. Introduce magnetic stimulus (for example, the magnet included in the evaluation kit). SLYU046 – January 2019 Submit Documentation Feedback DRV5055-5057EVM Copyright © 2019, Texas Instruments Incorporated 5 Hardware 3 www.ti.com Hardware The DRV505x is a linear Hall effect magnetic-sense solution that provides ease of use and high performance. The DRV5055-5057EVM is intended to provide basic functional evaluation of this device family. The fixture layout is not intended to be a model for the target circuit, nor is it laid out for electromagnetic compatibility (EMC) testing. The DRV5055-5057EVM consists of one PCB with each of the gain variants of the DRV5055, DRV5056, and DRV5057. The EVM kit also provides a USB cable for quick power-up, as well as a magnet for quick qualitative assessment of the DRV505x variants performance. 3.1 Features The layout of the DRV5055-5057EVM printed circuit board (PCB) is designed to provide the following features: • Evaluation of all gain options for the DRV505x • Easily access device pins through test points • Easily read voltage, mT, % duty cycle values, and microcontroller ADC memory values from the onboard LCD, where applicable • Toggle between devices with a press of the Device Select Switch, push-button S1. See the links in Table 3 for comprehensive information about the DRV505x family of devices. 3.2 Theory of Operation The DRV5055-5057EVM is a plug-and-play board, requiring only that the user supply power and provide a magnetic stimulus after the initial calibration. The ease of operation can be attributed to the onboard microcontroller. The source code for the microcontroller is available on the DRV5055, DRV5056, and DRV5057 web folders under Tools and Software. The basic operation of the microcontroller source code is outlined in the state machine diagram shown in Figure 1. Upon receiving power, the microcontroller registers are set up to properly interact with the other devices on the board. Then, a preliminary measurement of each DRV5055, DRV5056, and DRV5057 gain variant is taken. Make sure that the magnetic stimulus of interest is not present at this time because this measurement sets the 0 point in the mT measurement display. After calibration is complete, the LED for the DRV5055A1 powers on by default. At this point, the EVM microcontroller begins continuously sampling the DRV5055A1. Pressing push-button S1 results in the EVM sampling the next adjacent device. After every 32 samples are taken, the device calculates an average, and processes the data to fit the format selected by the slider switch K1. Startup 1. Setup Microcontroller Registers 2. Calibrate Measurements A: # of collected samples