TI的DRV8846高度集成步进马达驱动器参考资料
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DRV8846 双通道 H 桥步进电机驱动器
DRV8846 Dual H-Bridge Stepper Motor Driver
TI公司的DRV8846是高度集成的步进马达驱动器,包括两个H桥和微步进分度器,工作电压4-18V,驱动电流高达1A,主要用在打印机,扫描仪,视频安全摄像机和投映仪.本文介绍了DRV8846主要特性,功能框图,应用电路以及评估板主要特性,电路图和材料清单,以及3D打印机控制器(12V)主要特性,电路图和材料清单.
TI的DRV8846高度集成步进马达驱动器参考资料：
Detailed Description
1 Overview
The DRV8846 is an integrated motor driver solution for bipolar stepper motors. The device integrates 2 H-bridges that use NMOS low-side drivers and PMOS high-side drivers, current sense regulation circuitry, and a microstepping indexer.
2 Functional Block Diagram
3 Feature Description
3.1 PWM Motor Drivers
DRV8846 contains two identical H-bridge motor drivers with current-control PWM circuitry. Figure 6 shows a block diagram of the circuitry.
Figure 6. PWM Motor Driver Circuitry
3.2 Micro-Stepping Indexer
Table 2. Step Mode Settings
| M1 | M0 | STEP MODE |
|---|---|---|
| 0 | 0 | Full step (2-phase excitation), rising-edge only |
| 0 | Z | 1/2 step (1-2 phase excitation), rising-edge only |
| 0 | 1 | 1/4 step (W1-2 phase excitation), rising-edge only |
| Z | 0 | 8 microsteps/step, rising-edge only |
| Z | Z | 8 microsteps/step, rising and falling edges |
| Z | 1 | 16 microsteps/step, rising-edge only |
| 1 | 0 | 16 microsteps/step, rising and falling edges |
| 1 | Z | 32 microsteps/step, rising-edge only |
| 1 | 1 | 32 microsteps/step, rising and falling edges |
Table 3 shows the relative current and step directions for different step mode settings. At each rising edge of the STEP input, the indexer travels to the next state in the table. The direction is shown with the DIR pin high; if the DIR pin is low, the sequence is reversed. Positive current is defined as xOUT1 = positive with respect to xOUT2.
Table 3. Relative Current and Step Directions
| 1/32 STEP | 1/16 STEP | 1/8 STEP | 1/4 STEP | 1/2 STEP | FULL STEP 70% | WINDING CURRENT A | WINDING CURRENT B | ELECTRICAL ANGLE |
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 1 | 1 | 100% | 0% | 0 | |
| 2 | 100% | 5% | 3 | |||||
| 3 | 2 | 100% | 10% | 6 | ||||
| 4 | 99% | 15% | 8 | |||||
| 5 | 3 | 2 | 98% | 20% | 11 | |||
| 6 | 97% | 24% | 14 | |||||
| 7 | 4 | 96% | 29% | 17 | ||||
| 8 | 94% | 34% | 20 | |||||
| 9 | 5 | 3 | 2 | 92% | 38% | 23 | ||
| 10 | 90% | 43% | 25 | |||||
| 11 | 6 | 88% | 47% | 28 | ||||
| 12 | 86% | 51% | 31 | |||||
| 13 | 7 | 4 | 83% | 56% | 34 | |||
| 14 | 80% | 60% | 37 | |||||
| 15 | 8 | 77% | 63% | 39 | ||||
| 16 | 74% | 67% | 42 | |||||
| 17(1) | 9(1) | 5(1) | 3(1) | 2(1) | 1(1) | 71% | 71% | 45 |
| 18 | 67% | 74% | 48 | |||||
| 19 | 10 | 63% | 77% | 51 | ||||
| 20 | 60% | 80% | 53 | |||||
| 21 | 11 | 6 | 56% | 83% | 56 | |||
| 22 | 51% | 86% | 59 | |||||
| 23 | 12 | 47% | 88% | 62 | ||||
| 24 | 43% | 90% | 65 | |||||
| 25 | 13 | 7 | 4 | 38% | 92% | 68 | ||
| 26 | 34% | 94% | 70 | |||||
| 27 | 14 | 29% | 96% | 73 | ||||
| 28 | 24% | 97% | 76 | |||||
| 29 | 15 | 8 | 20% | 98% | 79 | |||
| 30 | 15% | 99% | 82 | |||||
| 31 | 16 | 10% | 100% | 84 | ||||
| 32 | 5% | 100% | 87 | |||||
| 33 | 17 | 9 | 5 | 3 | 0% | 100% | 90 | |
| 34 | –5% | 100% | 93 | |||||
| 35 | 18 | –10% | 100% | 96 | ||||
| 36 | –15% | 99% | 98 | |||||
| 37 | 19 | 10 | –20% | 98% | 101 | |||
| 38 | –24% | 97% | 104 | |||||
| 39 | 20 | –29% | 96% | 107 | ||||
| 40 | –34% | 94% | 110 | |||||
| 41 | 21 | 11 | 6 | –38% | 92% | 113 | ||
| 42 | –43% | 90% | 115 | |||||
| 43 | 22 | –47% | 88% | 118 | ||||
| 44 | –51% | 86% | 121 | |||||
| 45 | 23 | 12 | –56% | 83% | 124 | |||
| 46 | –60% | 80% | 127 | |||||
| 47 | 24 | –63% | 77% | 129 | ||||
| 48 | –67% | 74% | 132 | |||||
| 49 | 25 | 13 | 7 | 4 | 2 | –71% | 71% | 135 |
| 50 | –74% | 67% | 138 | |||||
| 51 | 26 | –77% | 63% | 141 | ||||
| 52 | –80% | 60% | 143 | |||||
| 53 | 27 | 14 | –83% | 56% | 146 | |||
| 54 | –86% | 51% | 149 | |||||
| 55 | 28 | –88% | 47% | 152 | ||||
| 56 | –90% | 43% | 155 | |||||
| 57 | 29 | 15 | 8 | –92% | 38% | 158 | ||
| 58 | –94% | 34% | 160 | |||||
| 59 | 30 | –96% | 29% | 163 | ||||
| 60 | –97% | 24% | 166 | |||||
| 61 | 31 | 16 | –98% | 20% | 169 | |||
| 62 | –99% | 15% | 172 | |||||
| 63 | 32 | –100% | 10% | 174 | ||||
| 64 | –100% | 5% | 177 | |||||
| 65 | 33 | 17 | 9 | 5 | –100% | 0% | 180 | |
| 66 | –100% | –5% | 183 | |||||
| 67 | 34 | –100% | –10% | 186 | ||||
| 68 | –99% | –15% | 188 | |||||
| 69 | 35 | 18 | –98% | –20% | 191 | |||
| 70 | –97% | –24% | 194 | |||||
| 71 | 36 | –96% | –29% | 197 | ||||
| 72 | –94% | –34% | 200 | |||||
| 73 | 37 | 19 | 10 | –92% | –38% | 203 | ||
| 74 | –90% | –43% | 205 | |||||
| 75 | 38 | –88% | –47% | 208 | ||||
| 76 | –86% | –51% | 211 | |||||
| 77 | 39 | 20 | –83% | –56% | 214 | |||
| 78 | –80% | –60% | 217 | |||||
| 79 | 40 | –77% | –63% | 219 | ||||
| 80 | –74% | –67% | 222 | |||||
| 81 | 41 | 21 | 11 | 6 | 3 | –71% | –71% | 225 |
| 82 | –67% | –74% | 228 | |||||
| 83 | 42 | –63% | –77% | 231 | ||||
| 84 | –60% | –80% | 233 | |||||
| 85 | 43 | 22 | –56% | –83% | 236 | |||
| 86 | –51% | –86% | 239 | |||||
| 87 | 44 | –47% | –88% | 242 | ||||
| 88 | –43% | –90% | 245 | |||||
| 89 | 45 | 23 | 12 | –38% | –92% | 248 | ||
| 90 | –34% | –94% | 250 | |||||
| 91 | 46 | –29% | –96% | 253 | ||||
| 92 | –24% | –97% | 256 | |||||
| 93 | 47 | 24 | –20% | –98% | 259 | |||
| 94 | –15% | –99% | 262 | |||||
| 95 | 48 | –10% | –100% | 264 | ||||
| 96 | –5% | –100% | 267 | |||||
| 97 | 49 | 25 | 13 | 7 | 0% | –100% | 270 | |
| 98 | 5% | –100% | 273 | |||||
| 99 | 50 | 10% | –100% | 276 | ||||
| 100 | 15% | –99% | 278 | |||||
| 101 | 51 | 26 | 20% | –98% | 281 | |||
| 102 | 24% | –97% | 284 | |||||
| 103 | 52 | 29% | –96% | 287 | ||||
| 104 | 34% | –94% | 290 | |||||
| 105 | 53 | 27 | 14 | 38% | –92% | 293 | ||
| 106 | 43% | –90% | 295 | |||||
| 107 | 54 | 47% | –88% | 298 | ||||
| 108 | 51% | –86% | 301 | |||||
| 109 | 55 | 28 | 56% | –83% | 304 | |||
| 110 | 60% | –80% | 307 | |||||
| 111 | 56 | 63% | –77% | 309 | ||||
| 112 | 67% | –74% | 312 | |||||
| 113 | 57 | 29 | 15 | 8 | 4 | 71% | –71% | 315 |
| 114 | 74% | –67% | 318 | |||||
| 115 | 58 | 77% | –63% | 321 | ||||
| 116 | 80% | –60% | 323 | |||||
| 117 | 59 | 30 | 83% | –56% | 326 | |||
| 118 | 86% | –51% | 329 | |||||
| 119 | 60 | 88% | –47% | 332 | ||||
| 120 | 90% | –43% | 335 | |||||
| 121 | 61 | 31 | 16 | 92% | –38% | 338 | ||
| 122 | 94% | –34% | 340 | |||||
| 123 | 62 | 96% | –29% | 343 | ||||
| 124 | 97% | –24% | 346 | |||||
| 125 | 63 | 32 | 98% | –20% | 349 | |||
| 126 | 99% | –15% | 352 | |||||
| 127 | 64 | 100% | –10% | 354 | ||||
| 128 | 100% | –5% | 357 |
(1) The indexer enters the home state after power-up, after exiting UVLO, or after exiting sleep mode.
3.3 Current Regulation
Table 4. Fixed Off-Time Selection
| TOFF_SEL | TOFF Duration |
|---|---|
| 0 | 20 μs |
| Z | 10 μs |
| 1 | 30 μs |
The full-scale (100%) chopping current is calculated as follows:
Equation 1. 
where
IFS Is The Full Scale Regulated Current
VREF Is The Voltage On The VREF Pin
RISENSE Is The Resistance Of The Sense Resistor
TORQUE Is The Scaling Percentage From The Torque DAC.
Example: Using VREF is 3.3 V, torque DAC = 100%, and a 500-mΩ sense resistor, the full-scale chopping current is 3.3 V / (6.6 × 500 mΩ) × 100% = 1 A.
The current for both motor windings is scaled depending on the I0 and I1 pins, which drive a 3-bit linear DAC, as inTable 5.
Table 5. Torque DAC Settings
| I1 | I0 | CURRENT SCALING (TORQUE) |
|---|---|---|
| 0 | 0 | 100% |
| 0 | Z | 87.5% |
| 0 | 1 | 75% |
| Z | 0 | 62.5% |
| Z | Z | 50% |
| Z | 1 | 37.5% |
| 1 | 0 | 25% |
| 1 | Z | 12.5% |
| 1 | 1 | 0% (outputs disabled) |
Table 6 gives the xISEN trip voltage at a given DAC code and I[1:0] setting.
Table 6. Torque DAC xISENS Trip Levels (VREF = 3.3 V)
| Sine DAC Code | Torque DAC I[1:0] Setting | |||||||
|---|---|---|---|---|---|---|---|---|
| 00 - 100% | 0Z - 87.5% | 01 - 75% | Z0 - 62.5% | ZZ - 50% | Z1 - 37.5% | 10 - 25% | 1Z - 12.5% | |
| 31 | 500 mV | 438 mV | 375 mV | 313 mV | 250 mV | 188 mV | 125 mV | 63 mV |
| 30 | 500 mV | 438 mV | 375 mV | 313 mV | 250 mV | 188 mV | 125 mV | 63 mV |
| 29 | 495 mV | 433 mV | 371 mV | 309 mV | 248 mV | 186 mV | 124 mV | 62 mV |
| 28 | 490 mV | 429 mV | 368 mV | 306 mV | 245 mV | 184 mV | 123 mV | 61 mV |
| 27 | 485 mV | 424 mV | 364 mV | 303 mV | 243 mV | 182 mV | 121 mV | 61 mV |
| 26 | 480 mV | 420 mV | 360 mV | 300 mV | 240 mV | 180 mV | 120 mV | 60 mV |
| 25 | 470 mV | 411 mV | 353 mV | 294 mV | 235 mV | 176 mV | 118 mV | 59 mV |
| 24 | 460 mV | 403 mV | 345 mV | 288 mV | 230 mV | 173 mV | 115 mV | 58 mV |
| 23 | 450 mV | 394 mV | 338 mV | 281 mV | 225 mV | 169 mV | 113 mV | 56 mV |
| 22 | 440 mV | 385 mV | 330 mV | 275 mV | 220 mV | 165 mV | 110 mV | 55 mV |
| 21 | 430 mV | 376 mV | 323 mV | 269 mV | 215 mV | 161 mV | 108 mV | 54 mV |
| 20 | 415 mV | 363 mV | 311 mV | 259 mV | 208 mV | 156 mV | 104 mV | 52 mV |
| 19 | 400 mV | 350 mV | 300 mV | 250 mV | 200 mV | 150 mV | 100 mV | 50 mV |
| 18 | 385 mV | 337 mV | 289 mV | 241 mV | 193 mV | 144 mV | 96 mV | 48 mV |
| 17 | 370 mV | 324 mV | 278 mV | 231 mV | 185 mV | 139 mV | 93 mV | 46 mV |
| 16 | 355 mV | 311 mV | 266 mV | 222 mV | 178 mV | 133 mV | 89 mV | 44 mV |
| 15 | 335 mV | 293 mV | 251 mV | 209 mV | 168 mV | 126 mV | 84 mV | 42 mV |
| 14 | 315 mV | 276 mV | 236 mV | 197 mV | 158 mV | 118 mV | 79 mV | 39 mV |
| 13 | 300 mV | 263 mV | 225 mV | 188 mV | 150 mV | 113 mV | 75 mV | 38 mV |
| 12 | 280 mV | 245 mV | 210 mV | 175 mV | 140 mV | 105 mV | 70 mV | 35 mV |
| 11 | 255 mV | 223 mV | 191 mV | 159 mV | 128 mV | 96 mV | 64 mV | 32 mV |
| 10 | 235 mV | 206 mV | 176 mV | 147 mV | 118 mV | 88 mV | 59 mV | 29 mV |
| 9 | 215 mV | 188 mV | 161 mV | 134 mV | 108 mV | 81 mV | 54 mV | 27 mV |
| 8 | 190 mV | 166 mV | 143 mV | 119 mV | 95 mV | 71 mV | 48 mV | 24 mV |
| 7 | 170 mV | 149 mV | 128 mV | 106 mV | 85 mV | 64 mV | 43 mV | 21 mV |
| 6 | 145 mV | 127 mV | 109 mV | 91 mV | 73 mV | 54 mV | 36 mV | 18 mV |
| 5 | 120 mV | 105 mV | 90 mV | 75 mV | 60 mV | 45 mV | 30 mV | 15 mV |
| 4 | 100 mV | 88 mV | 75 mV | 63 mV | 50 mV | 38 mV | 25 mV | 13 mV |
| 3 | 75 mV | 66 mV | 56 mV | 47 mV | 38 mV | 28 mV | 19 mV | 9 mV |
| 2 | 50 mV | 44 mV | 38 mV | 31 mV | 25 mV | 19 mV | 13 mV | 6 mV |
| 1 | 25 mV | 22 mV | 19 mV | 16 mV | 13 mV | 9 mV | 6 mV | 3 mV |
| 0 | 0 mV | 0 mV | 0 mV | 0 mV | 0 mV | 0 mV | 0 mV | 0 mV |
3.4 Decay Mode
After the chopping current threshold is reached, the drive current is interrupted, but due to the inductive nature of the motor, current must continue to flow for some period of time (called recirculation current). To handle this recirculation current, the H-bridge can operate in two different states, fast decay or slow decay (or a mixture of fast and slow decay).
Figure 7. Decay Modes
The DRV8846 supports fast, slow, mixed, and adaptive decay modes. With stepper motors, the decay mode is chosen for a given stepper motor and operating conditions to minimize mechanical noise and vibration.
Figure 8. Decay Behavior
Table 7. Decay Pins Configuration
| DEC1 | DEC0 | Decay Mode (Increasing Current) | Decay Mode (Decreasing Current) |
|---|---|---|---|
| 0 | 0 | Slow decay | Slow decay |
| 0 | Z | Slow decay | Mixed decay: 25% fast |
| 0 | 1 | Slow decay | Mixed decay: 1 tBLANK |
| Z | 0 | Mixed decay: 1 tBLANK | Mixed decay: 1 tBLANK |
| Z | Z | Mixed decay: 50% fast | Mixed decay: 50% fast |
| Z | 1 | Mixed decay: 25% fast | Mixed decay: 25% fast |
| 1 | 0 | Slow decay | Mixed decay: 50% fast |
| 1 | Z | Slow decay | Mixed decay: 12.5% fast |
| 1 | 1 | Slow decay | Fast decay |
Figure 9 shows increasing and decreasing current. When current is decreasing, the decay mode used is fast, slow, or mixed as commanded by the DEC1 and DEC0 pins. Three DEC pin selections allow for mixed decay during increasing current.
本文摘自中华ic网 www.1kic.com ,原文地址：http://www.1kic.com/news/knowledgeinfo/7134.html
中华IC网是国内首家永久免费上传和推广ic库存的网站，倡导真实IC现货免费展示，汇集数万家IC供应商和代理商库存信息,每日有大量工厂终端ic求购信息，是国内首个免费的ic现货发布平台，中华ic网提供更详尽更细化的IC报价参考、ic图片查询、ic代理商名录、IC求助、ic技术参数查询、ic代码查询及更人性化的IC竞价排名系统，是广大终端工厂及制造商采购ic及电子元器件原材料的理想平台。
Figure 9. Increasing and Decreasing Current
Adaptive decay mode simplifies the decay mode selection by dynamically changing to adjust for current level, step change, supply variation, BEMF, and load. To enable adaptive decay mode, pull the ADEC pin to logic high and pull DEC0 and DEC1 pins to logic high. The state of the ADEC pin is only evaluated when exiting sleep mode.
Figure 10. Adaptive Decay – Slow Decay Operation
Figure 11. Adaptive Decay – Mixed Decay Operation
Figure 12 shows a case for adaptive decay where a step occurs. The system starts with 1 tBLANK of fast decay and works up to 25% of tOFF time for fast decay until the current is regulated again.
Figure 12. Adaptive Decay – Step
