A3G4250D MEMS motion sensor: 3-axis digital output gyroscope Features Wide supply voltage: 2.4 V to 3.6 V 245 dps full scale I2C/SPI digital output interface 16-bit rate value data output 8-bit temperature data output Two digital output lines (interrupt and data ready) Integrated low and high-pass filters with userselectable bandwidth Ultra-stable over temperature and time Low-voltage-compatible IOs (1.8 V) Embedded power-down and sleep mode Embedded temperature sensor Embedded FIFO High shock survivability Extended operating temperature range (-40 C to +85 C) ECOPACK(R) RoHS and "Green" compliant AEC-Q100 qualification LGA-16 (4x4x1.1 mm3) The A3G4250D is a low-power 3-axis angular rate sensor able to provide unprecedented stability at zero rate level and sensitivity over temperature and time. It includes a sensing element and an IC interface capable of providing the measured angular rate to the external world through a standard SPI digital interface. An I2C-compatible interface is also available. The sensing element is manufactured using a dedicated micro-machining process developed by STMicroelectronics to produce inertial sensors and actuators on silicon wafers. The IC interface is manufactured using a CMOS process that allows a high level of integration to design a dedicated circuit which is trimmed to better match the sensing element characteristics. Applications In-dash car navigation Telematics, e-Tolling Motion control with MMI (man-machine interface) Appliances and robotics Table 1. Description The A3G4250D has a full scale of 245 dps and is capable of measuring rates with a userselectable bandwidth. The A3G4250D is available in a plastic land grid array (LGA) package and can operate within a temperature range of -40 C to +85 C. Device summary Order code Temperature range (C) Package A3G4250D -40 to +85 LGA-16 (4x4x1.1 mm3) -40 to +85 mm3) A3G4250DTR February 2012 LGA-16 (4x4x1.1 Doc 022768 Rev 3 Packing Tray Tape and reel 1/44 www.st.com 44 Contents A3G4250D Contents 1 Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1 2 Mechanical and electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1 Mechanical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3 Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.4 Communication interface characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.4.1 SPI - serial peripheral interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.4.2 I2C - inter IC control interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.5 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.6 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.7 3 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.6.1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.6.2 Zero-rate level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.6.3 Stability over temperature and time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Soldering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Main digital blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2 FIFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2.1 Bypass mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2.2 FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.2.3 Stream mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2.4 Retrieve data from FIFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4 Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5 Digital interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5.1 I2C serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5.1.1 5.2 2/44 I2C operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 SPI bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 5.2.1 SPI read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.2.2 SPI write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Doc 022768 Rev 3 A3G4250D Contents 5.2.3 SPI read in 3-wire mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6 Output register mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7 Register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 7.1 WHO_AM_I (0Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 7.2 CTRL_REG1 (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 7.3 CTRL_REG2 (21h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.4 CTRL_REG3 (22h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.5 CTRL_REG4 (23h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 7.6 CTRL_REG5 (24h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 7.7 REFERENCE/DATACAPTURE (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.8 OUT_TEMP (26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.9 STATUS_REG (27h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.10 OUT_X_L (28h), OUT_X_H (29h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.11 OUT_Y_L (2Ah), OUT_Y_H (2Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.12 OUT_Z_L (2Ch), OUT_Z_H (2Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.13 FIFO_CTRL_REG (2Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.14 FIFO_SRC_REG (2Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.15 INT1_CFG (30h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.16 INT1_SRC (31h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.17 INT1_THS_XH (32h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 7.18 INT1_THS_XL (33h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 7.19 INT1_THS_YH (34h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 7.20 INT1_THS_YL (35h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.21 INT1_THS_ZH (36h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.22 INT1_THS_ZL (37h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.23 INT1_DURATION (38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 8 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Doc 022768 Rev 3 3/44 List of tables A3G4250D List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. Table 22. Table 23. Table 24. Table 25. Table 26. Table 27. Table 28. Table 29. Table 30. Table 31. Table 32. Table 33. Table 34. Table 35. Table 36. Table 37. Table 38. Table 39. Table 40. Table 41. Table 42. Table 43. Table 44. Table 45. Table 46. Table 47. Table 48. 4/44 Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Filter values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Mechanical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Temp. sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 SPI slave timing values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 I2C slave timing values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 PLL low-pass filter component values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Serial interface pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 I2C terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 SAD+read/write patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Transfer when master is writing one byte to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Transfer when master is writing multiple bytes to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Transfer when master is receiving (reading) one byte of data from slave . . . . . . . . . . . . . 23 Transfer when master is receiving (reading) multiple bytes of data from slave . . . . . . . . . 23 Register address map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 WHO_AM_I register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 CTRL_REG1 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 CTRL_REG1 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 DR and BW configuration setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Power mode selection configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 CTRL_REG2 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 CTRL_REG2 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 High-pass filter mode configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 High-pass filter cut-off frequency configuration [Hz] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 CTRL_REG1 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 CTRL_REG3 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 CTRL_REG4 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 CTRL_REG4 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Self-test mode configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 CTRL_REG5 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 CTRL_REG5 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Out_Sel configuration settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 INT_SEL configuration settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 REFERENCE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 REFERENCE register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 OUT_TEMP register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 OUT_TEMP register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 STATUS_REG register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 STATUS_REG description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 REFERENCE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 REFERENCE register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 FIFO mode configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 FIFO_SRC register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 FIFO_SRC register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 INT1_CFG register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Doc 022768 Rev 3 A3G4250D Table 49. Table 50. Table 51. Table 52. Table 53. Table 54. Table 55. Table 56. Table 57. Table 58. Table 59. Table 60. Table 61. Table 62. Table 63. Table 64. Table 65. Table 66. List of tables INT1_CFG description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 INT1_SRC register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 INT1_SRC description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_XH register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_XH description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_XL register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_XL description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_YH register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_YH description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 INT1_THS_YL register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_THS_YL description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_THS_ZH register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_THS_ZH description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_THS_ZL register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_THS_ZL description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_DURATION register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 INT1_DURATION description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Doc 022768 Rev 3 5/44 List of figures A3G4250D List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. 6/44 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 A3G4250D external low-pass filter values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SPI slave timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 I2C slave timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Bypass mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Stream mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 FIFO access sequence in asynchronous mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 A3G4250D electrical connections and external component values . . . . . . . . . . . . . . . . . . 19 Read and write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 SPI read protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Multiple byte SPI read protocol (2-byte example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 SPI write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Multiple byte SPI write protocol (2-byte example). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 SPI read protocol in 3-wire mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 INT1_Sel and Out_Sel configuration block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Wait disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Wait enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 LGA-16: mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Doc 022768 Rev 3 A3G4250D 1 Block diagram and pin description Block diagram and pin description Figure 1. Block diagram + x,y,z X+ CHARGE AMP Y+ MIXER LOW-PASS FILTER D I G I T A L Z+ A D C 1 M U X ZYX- T E M P E R A T U R E DRIVING MASS Feedback loop REFERENCE TRIMMING CIRCUITS FIFO S E N S O R F I L T E R I N G I2C SPI CS SCL/SPC SDA/SDO/SDI SDO A D C 2 INT1 CONTROL LOGIC & INTERRUPT GEN. CLOCK & PHASE GENERATOR DRDY/INT2 AM07225v1 The vibration of the structure is maintained by drive circuitry in a feedback loop. The sensing signal is filtered and appears as a digital signal at the output. 1.1 Pin description Figure 2. Pin connection 13 RES 1 BOTTOM VIEW RES X RES 9 SDA/SDI/SDO SDO/SA0 5 CS DRDY/INT2 INT Doc 022768 Rev 3 Vdd_IO SCL/SPC 4 8 RES (TOP VIEW) DIRECTIONS OF THE DETECTABLE ANGULAR RATES 16 12 RES + Vdd + Y RES X GND 1 Z PLLFILT + AM07226v1 7/44 Block diagram and pin description Table 2. A3G4250D Pin description Pin# Name 1 Vdd_IO 2 SCL SPC I2C serial clock (SCL) SPI serial port clock (SPC) 3 SDA SDI SDO I2C serial data (SDA) SPI serial data input (SDI) 3-wire interface serial data output (SDO) 4 SDO SA0 SPI serial data output (SDO) I2C least significant bit of the device address (SA0) 5 CS 6 DRDY/INT2 7 INT1 8 Reserved Connect to GND 9 Reserved Connect to GND 10 Reserved Connect to GND 11 Reserved Connect to GND 12 Reserved Connect to GND 13 GND 14 PLLFILT Phase-locked loop filter (see Figure 3) 15 Reserved Connect to Vdd 16 Vdd Figure 3. Function Power supply for I/O pins SPI enable I2C/SPI mode selection (1: SPI idle mode / I2C communication enabled; 0: SPI communication mode / I2C disabled) Data ready/FIFO interrupt Programmable interrupt 0 V supply Power supply A3G4250D external low-pass filter values(a) #APACITOR FOR ,OW PASS FILTER TO PIN # # 2 '.$ !-V a. Pin 14 PLLFILT maximum voltage level is equal to Vdd. 8/44 Doc 022768 Rev 3 A3G4250D Block diagram and pin description Table 3. Filter values Parameter Typical value C1 10 nF C2 470 nF R2 10 k Doc 022768 Rev 3 9/44 Mechanical and electrical characteristics A3G4250D 2 Mechanical and electrical characteristics 2.1 Mechanical characteristics @ Vdd = 3.0 V, T = -40... +85 C, unless otherwise noted(b). Table 4. Symbol Mechanical characteristics Parameter FS Measurement range(2) So Sensitivity(3) SoDr Sensitivity change vs. temperature DVoff Digital zero-rate level(3) OffDr Zero-rate level change vs. temperature NL DST Rn Non linearity(2) Test condition Min. Max. Unit 10.1 mdps/digit 245 7.4 8.75 dps 2 -25 % +25 0.03 Best fit straight line Self-test output change Rate noise density Typ.(1) dps dps/C -5 0.2 +5 % FS 55 130 245 dps 0.03 0.15 dps/ sqrt(Hz) 105/208/ 420/840 121/239/ 483/966 Hz +85 C BW = 50 Hz ODR Digital output data rate 89/176/ 357/714 Top Operating temperature range -40 1. Typical specifications are not guaranteed; typical values at +25 C. 2. Guaranteed by design. 3. Across temperature and after MSL3 preconditioning. b. The product is factory calibrated at 3.0 V. The operational power supply range is specified in Table 5. 10/44 Doc 022768 Rev 3 A3G4250D 2.2 Mechanical and electrical characteristics Electrical characteristics @ Vdd = 3.0 V, T = -40... +85 C, unless otherwise noted(c). Table 5. Symbol Vdd Vdd_IO Idd Electrical characteristics Parameter Test condition Min. Typ.(1) Max. Unit 2.4 3.0 3.6 V Vdd+0.1 V 7.0 mA Supply voltage I/O pins supply voltage (2) 1.71 Supply current 4.8 6.1 IddSL Supply current in sleep mode(3) Selectable by digital interface 1.5 IddPdn Supply current in power-down mode(4) Selectable by digital interface 5 Top Operating temperature range -40 mA 10 A +85 C 1. Typical specifications are not guaranteed; typical values at +25 C. 2. It is possible to remove Vdd maintaining Vdd_IO without blocking the communication busses, in this condition the measurement chain is powered off. 3. Sleep mode introduces a faster turn-on time compared to power-down mode. 4. Verified at wafer level. 2.3 Temperature sensor characteristics @ Vdd = 3.0 V, T = 25 C, unless otherwise noted(d). Table 6. Symbol Temp. sensor characteristics Parameter TSDr Temperature sensor output change vs. temperature TODR Temperature refresh rate Top Test condition Min. - Operating temperature range -40 Typ.(1) Max. Unit -1 C/digit 1 Hz +85 C 1. Typical specifications are not guaranteed; typical values at +25 C. c. The product is factory calibrated at 3.0 V. d. The product is factory calibrated at 3.0 V. Doc 022768 Rev 3 11/44 Mechanical and electrical characteristics A3G4250D 2.4 Communication interface characteristics 2.4.1 SPI - serial peripheral interface Subject to general operating conditions for Vdd and Top. Table 7. SPI slave timing values Value(1) Symbol Parameter Unit Min. tc(SPC) SPI clock cycle fc(SPC) SPI clock frequency tsu(CS) CS setup time 5 th(CS) CS hold time 8 tsu(SI) SDI input setup time 5 th(SI) SDI input hold time 15 tv(SO) SDO valid output time th(SO) SDO output hold time tdis(SO) Max. 100 ns 10 MHz ns 50 6 SDO output disable time 50 1. Values are guaranteed at 10 MHz clock frequency for SPI with both 4 and 3 wires, based on characterization results; not tested in production. Figure 4. &6 SPI slave timing diagram(e) WF 63& WVX &6 WK &6 63& WVX 6, 6', WK 6, /6%,1 06%,1 WY 62 6'2 WGLV 62 WK 62 06%287 /6%287 !-V e. Measurement points are done at 0.2*Vdd_IO and 0.8*Vdd_IO, for both input and output ports. 12/44 Doc 022768 Rev 3 A3G4250D Mechanical and electrical characteristics I2C - inter IC control interface 2.4.2 Subject to general operating conditions for Vdd and Top. Table 8. I2C slave timing values I2C standard mode(1) Symbol f(SCL) I2C fast mode(1) Parameter Unit SCL clock frequency Min. Max. Min. Max. 0 100 0 400 tw(SCLL) SCL clock low time 4.7 1.3 tw(SCLH) SCL clock high time 4.0 0.6 tsu(SDA) SDA setup time 250 100 th(SDA) SDA data hold time 0 th(ST) START condition hold time 4 0.6 tsu(SR) Repeated START condition setup time 4.7 0.6 tsu(SP) STOP condition setup time 4 0.6 4.7 1.3 kHz s 3.45 ns 0 0.9 s s tw(SP:SR) Bus free time between STOP and START condition 1. Data based on standard I2C protocol requirement; not tested in production. Figure 5. I2C slave timing diagram(f) 5(3($7(' 67$57 67$57 WVX 65 WZ 6365 6'$ WI 6'$ WK 6'$ WVX 6'$ WU 6'$ 67$57 WVX 63 6723 6&/ WK 67 f. WZ 6&// WZ 6&/+ WU 6&/ WI 6&/ !-V Measurement points are done at 0.2*Vdd_IO and 0.8*Vdd_IO, for both ports. Doc 022768 Rev 3 13/44 Mechanical and electrical characteristics 2.5 A3G4250D Absolute maximum ratings Any stress above that listed as "Absolute maximum ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Table 9. Absolute maximum ratings Symbol Ratings Maximum value Unit Vdd Supply voltage -0.3 to 4.8 V TSTG Storage temperature range -40 to +125 C 10,000 g 2 (HBM) kV Sg ESD Acceleration g for 0.1 ms Electrostatic discharge protection This is a mechanical shock sensitive device, improper handling can cause permanent damage to the part This is an ESD sensitive device, improper handling can cause permanent damage to the part 14/44 Doc 022768 Rev 3 A3G4250D Mechanical and electrical characteristics 2.6 Terminology 2.6.1 Sensitivity An angular rate gyroscope is a device that produces a positive-going digital output for counter-clockwise rotation around the sensitive axis considered. Sensitivity describes the gain of the sensor and can be determined by applying a defined angular velocity to it. This value changes very little over temperature and time. 2.6.2 Zero-rate level The zero-rate level describes the actual output signal if there is no angular rate present. The zero-rate level of precise MEMS sensors is, to some extent, a result of stress to the sensor and, therefore, the zero-rate level can slightly change after mounting the sensor onto a printed circuit board or after exposing it to extensive mechanical stress. This value changes very little over temperature and time. 2.6.3 Stability over temperature and time Thanks to the unique single-driving mass approach and optimized design, ST gyroscopes are able to guarantee a perfect match of the MEMS mechanical mass and the ASIC interface, and deliver unprecedented levels of stability over temperature and time. With the zero-rate level and sensitivity performances, up to ten times better than equivalent products currently available on the market, the A3G4250D allows the user to avoid any further compensation and calibration during production for a faster time to market, easy application implementation, higher performance, and cost saving. 2.7 Soldering information The LGA package is compliant with the ECOPACK(R), RoHS and "Green" standard. It is qualified for soldering heat resistance according to JEDEC J-STD-020. Leave "pin 1 indicator" unconnected during soldering. Land pattern and soldering recommendations are available at www.st.com/. Doc 022768 Rev 3 15/44 Main digital blocks A3G4250D 3 Main digital blocks 3.1 Block diagram Figure 6. Block diagram /UT?3EL ,0& !$# ,0& (0& (0EN $ATA2EG &)&/ XX )# 30) ).4?3EL )NTERRUPT GENERATOR 3#2 2%' #/.& 2%' ).4 !-V 3.2 FIFO The A3G4250D embeds a 32-slot, 16-bit data FIFO for each of the three output channels: yaw, pitch, and roll. This allows consistent power saving for the system, as the host processor does not need to continuously poll data from the sensor. Instead, it can wake up only when needed and burst the significant data out from the FIFO. This buffer can work in five different modes. Each mode is selected by the FIFO_MODE bits in FIFO_CTRL_REG. Programmable watermark level, FIFO_empty or FIFO_Full events can be enabled to generate dedicated interrupts on the DRDY/INT2 pin (configured through CTRL_REG3), and event detection information is available in FIFO_SRC_REG. The watermark level can be configured to WTM4: 0 in FIFO_CTRL_REG. 3.2.1 Bypass mode In bypass mode, the FIFO is not operational and for this reason it remains empty. As illustrated in Figure 7, only the first address is used for each channel. The remaining FIFO slots are empty. When new data is available, the old data is overwritten. 16/44 Doc 022768 Rev 3 A3G4250D Main digital blocks Figure 7. Bypass mode XI YI ZI EMPTY X Y I Z X Y Z X Y Z X Y Z !-V 3.2.2 FIFO mode In FIFO mode, data from the yaw, pitch, and roll channels are stored in the FIFO. A watermark interrupt can be enabled (I2_WMK bit in CTRL_REG3), which is triggered when the FIFO is filled to the level specified in the WTM 4: 0 bits of FIFO_CTRL_REG. The FIFO continues filling until it is full (32 slots of 16-bit data for yaw, pitch, and roll). When full, the FIFO stops collecting data from the input channels. To restart data collection, it is necessary to write FIFO_CTRL_REG back to bypass mode. FIFO mode is represented in Figure 8. Doc 022768 Rev 3 17/44 Main digital blocks Figure 8. A3G4250D FIFO mode XI YI ZI X Y I Z X Y Z X Y Z X Y Z !-V 3.2.3 Stream mode In stream mode, data from yaw, pitch, and roll measurements are stored in the FIFO. A watermark interrupt can be enabled and set as in FIFO mode. The FIFO continues filling until full (32 slots of 16-bit data for yaw, pitch, and roll). When full, the FIFO discards the older data as the new data arrives. Programmable watermark level events can be enabled to generate dedicated interrupts on the DRDY/INT2 pin (configured through CTRL_REG3). Stream mode is represented in Figure 9. 18/44 Doc 022768 Rev 3 A3G4250D Main digital blocks Figure 9. Stream mode XI YI ZI X Y Z X Y Z X Y Z X Y Z X Y Z !-V 3.2.4 Retrieve data from FIFO FIFO data is read through the OUT_X, OUT_Y, and OUT_Z registers. When the FIFO is in stream, trigger or FIFO mode, a read operation to the OUT_X, OUT_Y or OUT_Z registers provides the data stored in the FIFO. Each time data is read from the FIFO, the oldest pitch, roll, and yaw data are placed in the OUT_X, OUT_Y and OUT_Z registers, and both single read and read_burst (X, Y & Z with auto-incremental address) operations can be used. In read_burst mode, when data included in OUT_Z_H is read, the system again starts to read information from addr OUT_X_L. The reading from FIFO may be executed either in synchronous or asynchronous mode. For correct data acquisition, the following points need to be followed: 1. 2. If reading is synchronous, all data should be acquired within one ODR cycle If reading is asynchronous, an appropriate FIFO access sequence must be applied: a) A single dummy read @ 28h (increment bit = 0) to update data out b) A burst read of 6 bytes from 2Ah (Y low) up to 29h: - Y(2A-2Bh) - Z(2C - 2Dh) - X(28-29h) Figure 10 illustrates the correct sequence with a flow diagram: Doc 022768 Rev 3 19/44 Main digital blocks A3G4250D Figure 10. FIFO access sequence in asynchronous mode No WTM = `1' Yes Read FIFO SRC (2Fh) n = FSS<4-0> Dummy Read from `28h' (increment bit =`0') n-- Burst Read from `2Ah' of 6 registers (Y, Z, X) No n=0 Yes Example: FSS = 1 read twice FSS = 2 read 3 times AM10248V1 If the above sequence is not followed, the acquisition from FIFO may lead to corrupted data. 20/44 Doc 022768 Rev 3 A3G4250D Application hints Figure 11. A3G4250D electrical connections and external component values + Vdd GND GND Z + 10 F Y Vdd X PLLFILT 100 nF 1 16 + (TOP VIEW) DIRECTIONS OF THE DETECTABLE ANGULAR RATES X Vdd_IO 13 1 12 TOP VIEW SCL/SPC SDA_SDI_SDO 4 SDO/SA0 9 8 5 C1 10kOhm GND 10nF 470nF CS C2 DR INT Vdd I2C bus Rpu PLLFILT R2 GND 4 Application hints Rpu = 10kOhm SCL/SPC SDA_SDI_SDO Pull-up to be added when I2C interface is used AM07949V1 Power supply decoupling capacitors (100 nF ceramic or polyester +10 F) should be placed as near as possible to the device (common design practice). If Vdd and Vdd_IO are not connected together, power supply decoupling capacitors (100 nF and 10 F between Vdd and common ground, 100 nF between Vdd_IO and common ground) should be placed as near as possible to the device (common design practice). The A3G4250D IC includes a PLL (phase locked loop) circuit to synchronize driving and sensing interfaces. Capacitors and resistors must be added at the PLLFILT pin (as shown in Figure 11) to implement a second-order low-pass filter. Table 10 summarizes the PLL lowpass filter component values. Table 10. PLL low-pass filter component values Component Value C1 10 nF 10% Doc 022768 Rev 3 21/44 Application hints Table 10. 22/44 A3G4250D PLL low-pass filter component values Component Value C2 470 nF 10% R2 10 k 10% Doc 022768 Rev 3 A3G4250D 5 Digital interfaces Digital interfaces The registers embedded in the A3G4250D may be accessed through both the I2C and SPI serial interfaces. The latter may be software-configured to operate either in 3-wire or 4-wire interface mode. The serial interfaces are mapped onto the same pins. To select/exploit the I2C interface, the CS line must be tied high (i.e., connected to Vdd_IO). Table 11. Serial interface pin description Pin name Pin description CS SPI enable I2C/SPI mode selection (1: SPI idle mode / I2C communication enabled; 0: SPI communication mode / I2C disabled) SCL/SPC SDA/SDI/SDO I2C serial data (SDA) SPI serial data input (SDI) 3-wire interface serial data output (SDO) SPI serial data output (SDO) I2C least significant bit of the device address SDO 5.1 I2C serial clock (SCL) SPI serial port clock (SPC) I2C serial interface The A3G4250D I2C is a bus slave. The I2C is employed to write data to registers whose content can also be read back. The relevant I2C terminology is given in the table below. Table 12. I2C terminology Term Transmitter Receiver Description The device which sends data to the bus The device which receives data from the bus Master The device which initiates a transfer, generates clock signals and terminates a transfer Slave The device addressed by the master There are two signals associated with the I2C bus: the serial clock line (SCL) and the serial data line (SDA). The latter is a bi-directional line used for sending and receiving the data to/from the interface. Both lines must be connected to Vdd_IO through an external pull-up resistor. When the bus is free both the lines are high. The I2C interface is compliant with fast mode (400 kHz) I2C standards as well as with normal mode. Doc 022768 Rev 3 23/44 Digital interfaces 5.1.1 A3G4250D I2C operation The transaction on the bus is started through a START (ST) signal. A START condition is defined as a HIGH to LOW transition on the data line while the SCL line is held HIGH. After this has been transmitted by the master, the bus is considered busy. The next byte of data transmitted after the start condition contains the address of the slave in the first 7 bits and the eighth bit tells whether the master is receiving data from the slave or transmitting data to the slave. When an address is sent, each device in the system compares the first 7 bits after a start condition with its address. If they match, the device considers itself addressed by the master. The slave address (SAD) associated with the A3G4250D is 110100xb. The SDO pin can be used to modify the least significant bit (LSb) of the device address. If the SDO pin is connected to the voltage supply, LSb is `1' (address 1101001b). Otherwise, when the SDO pin is connected to ground, the LSb value is `0' (address 1101000b). This solution permits the connection and addressing of two different gyroscopes to the same I2C bus. Data transfer with acknowledge is mandatory. The transmitter must release the SDA line during the acknowledge pulse. The receiver must then pull the data line LOW so that it remains stable low during the HIGH period of the acknowledge clock pulse. A receiver which has been addressed is obliged to generate an acknowledge after each byte of data received. The I2C embedded in the A3G4250D behaves like a slave device, and the following protocol must be adhered to. After the START (ST) condition, a slave address is sent. Once a slave acknowledge (SAK) has been returned, an 8-bit sub-address is transmitted. The 7 LSb represent the actual register address while the MSb enables address auto-increment. If the MSb of the SUB field is 1, the SUB (register address) is automatically incremented to allow multiple data read/write. The slave address is completed with a read/write bit. If the bit is `1' (read), a REPEATED START (SR) condition must be issued after the two sub-address bytes; if the bit is `0' (write) the master transmits to the slave with the direction unchanged. Table 13 describes how the SAD+read/write bit pattern is composed, listing all the possible configurations. Table 13. Command SAD[6:1] SAD[0] = SDO R/W Read 110100 0 1 11010001 (D1h) Write 110100 0 0 11010000 (D0h) Read 110100 1 1 11010011 (D3h) Write 110100 1 0 11010010 (D2h) Table 14. Master Slave 24/44 SAD+read/write patterns SAD+R/W Transfer when master is writing one byte to slave ST SAD + W SUB SAK Doc 022768 Rev 3 DATA SAK SP SAK A3G4250D Digital interfaces Table 15. Master Transfer when master is writing multiple bytes to slave ST SAD + W Slave SAK Table 16. Master ST SAD + W DATA SAK SUB SAK SAK SP SAK SR SAD + R SAK NMAK SAK SP DATA Transfer when master is receiving (reading) multiple bytes of data from slave Master ST SAD+W Slave DATA Transfer when master is receiving (reading) one byte of data from slave Slave Table 17. SUB SUB SAK SR SAD+R SAK MAK SAK DATA MAK DATA NMAK SP DATA Data are transmitted in byte format (DATA). Each data transfer contains 8 bits. The number of bytes transferred per transfer is unlimited. Data is transferred with the most significant bit (MSb) first. If a receiver cannot receive another complete byte of data until it has performed some other function, it can hold the clock line SCL LOW to force the transmitter into a wait state. Data transfer only continues when the receiver is ready for another byte and releases the data line. If a slave receiver does not acknowledge the slave address (i.e., it is not able to receive because it is performing some real-time function) the data line must be left HIGH by the slave. The master can then abort the transfer. A LOW to HIGH transition on the SDA line while the SCL line is HIGH is defined as a STOP condition. Each data transfer must be terminated by the generation of a STOP (SP) condition. In order to read multiple bytes, it is necessary to assert the most significant bit of the subaddress field. In other words, SUB(7) must be equal to 1, while SUB(6-0) represents the address of the first register to be read. In the presented communication format, MAK is "master acknowledge" and NMAK is "no master acknowledge". 5.2 SPI bus interface The SPI is a bus slave. The SPI allows writing and reading of the device registers. The serial interface interacts with the external world through 4 wires: CS, SPC, SDI, and SDO. Doc 022768 Rev 3 25/44 Digital interfaces A3G4250D Figure 12. Read and write protocol CS SPC SDI DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0 RW MS AD5 AD4 AD3 AD2 AD1 AD0 SDO DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 CS is the serial port enable and is controlled by the SPI master. It goes low at the start of the transmission and returns to high at the end. SPC is the serial port clock and is controlled by the SPI master. It is stopped high when CS is high (no transmission). SDI and SDO are, respectively, the serial port data input and output. These lines are driven at the falling edge of SPC and should be captured at the rising edge of SPC. Both the read register and write register commands are completed in 16 clock pulses, or in multiples of 8 in case of multiple read/write bytes. Bit duration is the time between two falling edges of SPC. The first bit (bit 0) starts at the first falling edge of SPC after the falling edge of CS while the last bit (bit 15, bit 23, etc.) starts at the last falling edge of SPC just before the rising edge of CS. Bit 0: RW bit. When 0, the data DI(7:0) is written to the device. When 1, the data DO(7:0) from the device is read. In the latter case, the chip drives SDO at the start of bit 8. Bit 1: MS bit. When 0, the address remains unchanged in multiple read/write commands. When 1, the address is auto-incremented in multiple read/write commands. Bit 2-7: address AD(5:0). This is the address field of the indexed register. Bit 8-15: data DI(7:0) (write mode). This is the data that is written to the device (MSb first). Bit 8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first). In multiple read/write commands, further blocks of 8 clock periods are added. When the MS bit is 0, the address used to read/write data remains the same for every block. When the MS bit is 1, the address used to read/write data is incremented at every block. The function and the behavior of SDI and SDO remain unchanged. 5.2.1 SPI read Figure 13. SPI read protocol CS SPC SDI RW MS AD5 AD4 AD3 AD2 AD1 AD0 SDO DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 26/44 Doc 022768 Rev 3 A3G4250D Digital interfaces The SPI read command is performed with 16 clock pulses. A multiple byte read command is performed by adding blocks of 8 clock pulses to the previous one. Bit 0: READ bit. The value is 1. Bit 1: MS bit. When 0, do not increment address; when 1, increment address in multiple reading. Bit 2-7: address AD(5:0). This is the address field of the indexed register. Bit 8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first). Bit 16-...: data DO(...-8). Further data in multiple byte reading. Figure 14. Multiple byte SPI read protocol (2-byte example) CS SPC SDI RW MS AD5 AD4 AD3 AD2 AD1 AD0 SDO DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 DO15DO14DO13DO12DO11DO10DO9 DO8 5.2.2 SPI write Figure 15. SPI write protocol CS SPC SDI DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0 RW MS AD5 AD4 AD3 AD2 AD1 AD0 The SPI write command is performed with 16 clock pulses. A multiple byte write command is performed by adding blocks of 8 clock pulses to the previous one. Bit 0: WRITE bit. The value is 0. Bit 1: MS bit. When 0, do not increment address; when 1, increment address in multiple writing. Bit 2 -7: address AD(5:0). This is the address field of the indexed register. Bit 8-15: data DI(7:0) (write mode). This is the data that is written to the device (MSb first). Bit 16-...: data DI(...-8). Further data in multiple byte writing. Doc 022768 Rev 3 27/44 Digital interfaces A3G4250D Figure 16. Multiple byte SPI write protocol (2-byte example) CS SPC SDI DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0 DI15 DI14 DI13 DI12 DI11 DI10 DI9 DI8 RW MS AD5 AD4 AD3 AD2 AD1 AD0 5.2.3 SPI read in 3-wire mode 3-wire mode is entered by setting the SIM (SPI serial interface mode selection) bit to 1 in CTRL_REG2. Figure 17. SPI read protocol in 3-wire mode CS SPC SDI/O DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 RW MS AD5 AD4 AD3 AD2 AD1 AD0 The SPI read command is performed with 16 clock pulses: Bit 0: READ bit. The value is 1. Bit 1: MS bit. When 0, do not increment address; when 1, increment address in multiple reading. Bit 2-7: address AD(5:0). This is the address field of the indexed register. Bit 8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first). The multiple read command is also available in 3-wire mode. Note: If the A3G4250D is used in a multi-SPI slave environment (several devices sharing the same SPI bus), the accelerometer can be forced by software to remain in SPI mode. This objective can be achieved by sending, at the beginning of the SPI communication, the following sequence to the device: a = read(0x05) write(0x05, (0x20 OR a)) The programming of this register makes it possible to enhance the robustness of the SPI system. 28/44 Doc 022768 Rev 3 A3G4250D 6 Output register mapping Output register mapping Table 18 below provides a listing of the 8-bit registers embedded in the device and the related addresses: Table 18. Register address map Register address Name Type Default Hex Binary - Reserved - 00-0E WHO_AM_I r 0F Reserved - 10-1F CTRL_REG1 rw 20 010 0000 00000111 CTRL_REG2 rw 21 010 0001 00000000 CTRL_REG3 rw 22 010 0010 00000000 CTRL_REG4 rw 23 010 0011 00000000 CTRL_REG5 rw 24 010 0100 00000000 REFERENCE rw 25 010 0101 00000000 OUT_TEMP r 26 010 0110 Output STATUS_REG r 27 010 0111 Output OUT_X_L r 28 010 1000 Output OUT_X_H r 29 010 1001 Output OUT_Y_L r 2A 010 1010 Output OUT_Y_H r 2B 010 1011 Output OUT_Z_L r 2C 010 1100 Output OUT_Z_H r 2D 010 1101 Output FIFO_CTRL_REG rw 2E 010 1110 00000000 FIFO_SRC_REG r 2F 010 1111 INT1_CFG rw 30 011 0000 00000000 INT1_SRC r 31 011 0001 INT1_TSH_XH rw 32 011 0010 00000000 INT1_TSH_XL rw 33 011 0011 00000000 INT1_TSH_YH rw 34 011 0100 00000000 INT1_TSH_YL rw 35 011 0101 00000000 INT1_TSH_ZH rw 36 011 0110 00000000 INT1_TSH_ZL rw 37 011 0111 00000000 INT1_DURATION rw 38 011 1000 00000000 Doc 022768 Rev 3 Comment - 000 1111 11010011 - - Output Output 29/44 Output register mapping A3G4250D Registers marked as Reserved must not be changed. Writing to those registers may change calibration data and therefore lead to a non-proper working device. The content of the registers that are loaded at boot should not be changed. They contain the factory calibration values. Their content is automatically restored when the device is powered up. 30/44 Doc 022768 Rev 3 A3G4250D 7 Register description Register description The device contains a set of registers which are used to control its behavior and to retrieve rate data. The register addresses, made up of 7 bits, are used to identify them and to write the data through the serial interface. 7.1 WHO_AM_I (0Fh) Table 19. WHO_AM_I register 1 1 0 1 0 0 1 1 BW0 PD Zen Yen Xen Device identification register. 7.2 CTRL_REG1 (20h) Table 20. DR1 Table 21. CTRL_REG1 register DR0 BW1 CTRL_REG1 description DR1-DR0 Output data rate selection. Refer to Table 22 BW1-BW0 Bandwidth selection. Refer to Table 22 PD Power-down mode enable. Default value: 0 (0: power-down mode, 1: normal mode or sleep mode) Zen Z-axis enable. Default value: 1 (0: Z-axis disabled; 1: Z-axis enabled) Yen Y-axis enable. Default value: 1 (0: Y-axis disabled; 1: Y-axis enabled) Xen X-axis enable. Default value: 1 (0: X-axis disabled; 1: X-axis enabled) DR<1:0> is used to set ODR selection. BW <1:0> is used to set Bandwidth selection. In the following table (Table 22) all frequencies resulting in a combination of DR / BW bits are reported. Table 22. DR and BW configuration setting DR <1:0> BW <1:0> ODR [Hz] Cut-off 00 00 100 12.5 00 01 100 25 00 10 100 25 00 11 100 25 Doc 022768 Rev 3 31/44 Register description Table 22. A3G4250D DR and BW configuration setting (continued) DR <1:0> BW <1:0> ODR [Hz] Cut-off 01 00 200 12.5 01 01 200 25 01 10 200 50 01 11 200 70 10 00 400 20 10 01 400 25 10 10 400 50 10 11 400 110 11 00 800 30 11 01 800 35 11 10 800 50 11 11 800 110 Combination of PD, Zen, Yen, and Xen are used to set the device in different modes (power-down / normal / sleep mode) according to the following table. Table 23. Power mode selection configuration Mode 7.3 PD Zen Yen Xen Power-down 0 - - - Sleep 1 0 0 0 Normal 1 - - - CTRL_REG2 (21h) Table 24. (1) 0 CTRL_REG2 register 0(1) HPM1 HPM1 HPCF3 HPCF2 HPCF1 1. Value loaded at boot. This value must not be changed. Table 25. CTRL_REG2 description HPM1HPM0 High-pass filter mode selection. Default value: 00 Refer to Table 26 HPCF3HPCF0 High-pass filter cut-off frequency selection Refer to Table 28 Table 26. High-pass filter mode configuration HPM1 0 32/44 HPM0 0 High-pass filter mode Normal mode (reset reading HP_RESET_FILTER) Doc 022768 Rev 3 HPCF0 A3G4250D Register description Table 26. 0 1 Reference signal for filtering 1 0 Normal mode 1 1 Auto-reset on interrupt event Table 27. 7.4 High-pass filter cut-off frequency configuration [Hz] HPCF3 ODR= 100 Hz ODR= 200 Hz ODR= 400 Hz ODR= 800 Hz 0000 8 15 30 56 0001 4 8 15 30 0010 2 4 8 15 0011 1 2 4 8 0100 0.5 1 2 4 0101 0.2 0.5 1 2 0110 0.1 0.2 0.5 1 0111 0.05 0.1 0.2 0.5 1000 0.02 0.05 0.1 0.2 1001 0.01 0.02 0.05 0.1 CTRL_REG3 (22h) Table 28. I1_Int1 Table 29. 7.5 High-pass filter mode configuration CTRL_REG1 register I1_Boot H_Lactive PP_OD I2_DRDY I2_WTM I2_ORun I2_Empty CTRL_REG3 description I1_Int1 Interrupt enable on the INT1 pin. Default value 0. (0: disable; 1: enable) I1_Boot Boot status available on INT1. Default value 0. (0: disable; 1: enable) H_Lactive Interrupt active configuration on INT1. Default value 0. (0: high; 1: low) PP_OD Push-pull / open drain. Default value: 0. (0: push-pull; 1: open drain) I2_DRDY Date ready on DRDY/INT2. Default value 0. (0: disable; 1: enable) I2_WTM FIFO watermark interrupt on DRDY/INT2. Default value: 0. (0: disable; 1: enable) I2_ORun FIFO overrun interrupt on DRDY/INT2 Default value: 0. (0: disable; 1: enable) I2_Empty FIFO empty interrupt on DRDY/INT2. Default value: 0. (0: disable; 1: enable) CTRL_REG4 (23h) Table 30. 0 CTRL_REG4 register BLE 0 0 Doc 022768 Rev 3 - ST1 ST0 SIM 33/44 Register description A3G4250D Table 31. CTRL_REG4 description BLE Big/little endian data selection. Default value 0. (0: data LSB @ lower address; 1: data MSB @ lower address) ST1-ST0 Self-test enable. Default value: 00 (00: self-test disabled; Other: see Table ) SIM SPI serial interface mode selection. Default value: 0 (0: 4-wire interface; 1: 3-wire interface). Table 32. Self-test mode configuration ST1 ST0 Self-test mode 0 0 Normal mode 0 1 Self-test 0 (+)(1) 1 0 -- 1 1 Self-test 1 (-)(1) 1. DST sign (absolute value in Table 4). 7.6 CTRL_REG5 (24h) Table 33. BOOT Table 34. 34/44 CTRL_REG5 register FIFO_EN -- HPen INT1_Sel1 INT1_Sel0 CTRL_REG5 description BOOT Reboot memory content. Default value: 0 (0: normal mode; 1: reboot memory content) FIFO_EN FIFO enable. Default value: 0 (0: FIFO disable; 1: FIFO enable) HPen High-pass filter enable. Default value: 0 (0: HPF disabled; 1: HPF enabled (see Figure 19) INT1_Sel1INT1_Sel0 INT1 selection configuration. Default value: 0 (see Figure 19) Out_Sel1Out_Sel1 Out selection configuration. Default value: 0 (see Figure 19) Doc 022768 Rev 3 Out_Sel1 Out_Sel0 A3G4250D Register description Figure 18. INT1_Sel and Out_Sel configuration block diagram Out_Sel <1:0> 00 01 0 LPF2 ADC LPF1 HPF 10 11 DataReg FIFO 32x16x3 1 INT1_Sel <1:0> HPen 10 11 01 Interrupt generator 00 AM07949V2 Table 35. Out_Sel configuration settings Hpen OUT_SEL1 OUT_SEL0 x 0 0 Data in DataReg and FIFO are non-highpass-filtered x 0 1 Data in DataReg and FIFO are high-passfiltered 0 1 x Data in DataReg and FIFO are low-passfiltered by LPF2 1 1 x Data in DataReg and FIFO are high-pass and low-pass-filtered by LPF2 Table 36. Description INT_SEL configuration settings Hpen INT_SEL1 INT_SEL2 x 0 0 Non-high-pass-filtered data are used for interrupt generation x 0 1 High-pass-filtered data are used for interrupt generation 0 1 x Low-pass-filtered data are used for interrupt generation 1 1 x High-pass and low-pass-filtered data are used for interrupt generation Doc 022768 Rev 3 Description 35/44 Register description 7.7 A3G4250D REFERENCE/DATACAPTURE (25h) Table 37. Ref7 REFERENCE register Ref6 Table 38. Ref3 Ref2 Ref1 Ref0 Reference value for interrupt generation. Default value: 0 OUT_TEMP (26h) Table 39. Temp7 OUT_TEMP register Temp6 Table 40. Temp5 Temp4 Temp3 Temp2 Temp1 Temp0 OUT_TEMP register description Temp7-Temp0 7.9 Ref4 REFERENCE register description Ref 7-Ref0 7.8 Ref5 Temperature data. STATUS_REG (27h) Table 41. ZYXOR STATUS_REG register ZOR Table 42. YOR XOR ZYXDA ZDA YDA XDA STATUS_REG description X, Y, Z-axis data overrun. Default value: 0 ZYXOR (0: no overrun has occurred; 1: new data has overwritten the previous one before it was read) ZOR Z-axis data overrun. Default value: 0 (0: no overrun has occurred; 1: a new data for the Z-axis has overwritten the previous one) YOR Y-axis data overrun. Default value: 0 (0: no overrun has occurred; 1: a new data for the Y-axis has overwritten the previous one) XOR X-axis data overrun. Default value: 0 (0: no overrun has occurred; 1: a new data for the X-axis has overwritten the previous one) ZYXDA X, Y, Z-axis new data available. Default value: 0 (0: a new set of data is not yet available; 1: a new set of data is available) 36/44 ZDA Z-axis new data available. Default value: 0 (0: a new data for the Z-axis is not yet available; 1: a new data for the Z-axis is available) YDA Y-axis new data available. Default value: 0 (0: a new data for the Y-axis is not yet available;1: a new data for the Y-axis is available) XDA X-axis new data available. Default value: 0 (0: a new data for the X-axis is not yet available; 1: a new data for the X-axis is available) Doc 022768 Rev 3 A3G4250D 7.10 Register description OUT_X_L (28h), OUT_X_H (29h) X-axis angular rate data. The value is expressed as 2's complement. 7.11 OUT_Y_L (2Ah), OUT_Y_H (2Bh) Y-axis angular rate data. The value is expressed as 2's complement. 7.12 OUT_Z_L (2Ch), OUT_Z_H (2Dh) Z-axis angular rate data. The value is expressed as 2's complement. 7.13 FIFO_CTRL_REG (2Eh) Table 43. REFERENCE register FM2 FM1 Table 44. WTM4 WTM3 WTM2 WTM1 WTM0 FSS1 FSS0 REFERENCE register description FM2-FM0 FIFO mode selection. Default value: 00 WTM4-WTM0 FIFO threshold. Watermark level setting Table 45. FIFO mode configuration FM2 7.14 FM0 FM1 FM0 FIFO mode 0 0 0 Bypass mode 0 0 1 FIFO mode 0 1 0 Stream mode FIFO_SRC_REG (2Fh) Table 46. WTM Table 47. FIFO_SRC register OVRN EMPTY FSS4 FSS3 FSS2 FIFO_SRC register description WTM Watermark status. (0: FIFO filling is lower than WTM level; 1: FIFO filling is equal or higher than WTM level) OVRN Overrun bit status. (0: FIFO is not completely filled; 1: FIFO is completely filled) Doc 022768 Rev 3 37/44 Register description Table 47. 7.15 A3G4250D FIFO_SRC register description (continued) EMPTY FIFO empty bit. (0: FIFO not empty; 1: FIFO empty) FSS4-FSS1 FIFO stored data level INT1_CFG (30h) Table 48. AND/OR Table 49. INT1_CFG register LIR ZHIE ZLIE YHIE YLIE XHIE XLIE INT1_CFG description AND/OR AND/OR combination of interrupt events. Default value: 0 (0: OR combination of interrupt events 1: AND combination of interrupt events LIR Latch interrupt request. Default value: 0 (0: interrupt request not latched; 1: interrupt request latched) Cleared by reading the INT1_SRC reg. ZHIE Enable interrupt generation on Z high event. Default value: 0 (0: disable interrupt request; 1: enable interrupt request on measured rate value higher than preset threshold) ZLIE Enable interrupt generation on Z low event. Default value: 0 (0: disable interrupt request; 1: enable interrupt request on measured rate value lower than preset threshold) YHIE Enable interrupt generation on Y high event. Default value: 0 (0: disable interrupt request; 1: enable interrupt request on measured rate value higher than preset threshold) YLIE Enable interrupt generation on Y low event. Default value: 0 (0: disable interrupt request; 1: enable interrupt request on measured rate value lower than preset threshold) XHIE Enable interrupt generation on X high event. Default value: 0 (0: disable interrupt request; 1: enable interrupt request on measured rate value higher than preset threshold) XLIE Enable interrupt generation on X low event. Default value: 0 (0: disable interrupt request; 1: enable interrupt request on measured rate value lower than preset threshold) Configuration register for interrupt source. 7.16 INT1_SRC (31h) Table 50. 0 38/44 INT1_SRC register IA ZH ZL Doc 022768 Rev 3 YH YL XH XL A3G4250D Register description Table 51. INT1_SRC description IA Interrupt active. Default value: 0 (0: no interrupt has been generated; 1: one or more interrupts have been generated) ZH Z high. Default value: 0 (0: no interrupt, 1: Z high event has occurred) ZL Z low. Default value: 0 (0: no interrupt; 1: Z low event has occurred) YH Y high. Default value: 0 (0: no interrupt, 1: Y high event has occurred) YL Y low. Default value: 0 (0: no interrupt, 1: Y low event has occurred) XH X high. Default value: 0 (0: no interrupt, 1: X high event has occurred) XL X low. Default value: 0 (0: no interrupt, 1: X low event has occurred) Interrupt source register. Read only register. Reading at this address clears the INT1_SRC IA bit (and eventually the interrupt signal on the INT1 pin) and allows the refreshment of data in the INT1_SRC register if the latched option is chosen. 7.17 INT1_THS_XH (32h) Table 52. - Table 53. INT1_THS_XH register THSX14 THSX11 THSX10 THSX9 THSX8 THSX1 THSX0 THSY9 THSY8 Interrupt threshold. Default value: 0000 0000 INT1_THS_XL (33h) Table 54. THSX7 Table 55. INT1_THS_XL register THSX6 THSX5 THSX4 THSX3 THSX2 INT1_THS_XL description THSX7 - THSX0 7.19 THSX12 INT1_THS_XH description THSX14 - THSX9 7.18 THSX13 Interrupt threshold. Default value: 0000 0000 INT1_THS_YH (34h) Table 56. - Table 57. INT1_THS_YH register THSY14 THSY13 THSY12 THSY11 THSY10 INT1_THS_YH description THSY14 - THSY9 Interrupt threshold. Default value: 0000 0000 Doc 022768 Rev 3 39/44 Register description 7.20 A3G4250D INT1_THS_YL (35h) Table 58. THSR7 Table 59. INT1_THS_YL register THSY6 - Table 61. THSY2 THSY1 THSY0 THSZ9 THSZ8 THSZ1 THSZ0 D1 D0 Interrupt threshold. Default value: 0000 0000 INT1_THS_ZH register THSZ14 THSZ13 THSZ12 THSZ11 THSZ10 INT1_THS_ZH description THSZ14 - THSZ9 Interrupt threshold. Default value: 0000 0000 INT1_THS_ZL (37h) Table 62. THSZ7 Table 63. INT1_THS_ZL register THSZ6 THSZ5 THSZ4 THSZ3 THSZ2 INT1_THS_ZL description THSZ7 - THSZ0 7.23 THSY3 INT1_THS_ZH (36h) Table 60. 7.22 THSY4 INT1_THS_YL description THSY7 - THSY0 7.21 THSY5 Interrupt threshold. Default value: 0000 0000 INT1_DURATION (38h) Table 64. WAIT Table 65. INT1_DURATION register D6 D5 D4 D3 D2 INT1_DURATION description WAIT WAIT enable. Default value: 0 (0: disable; 1: enable) D6 - D0 Duration value. Default value: 000 0000 D6 - D0 bits set the minimum duration of the interrupt event to be recognized. Duration steps and maximum values depend on the ODR chosen. WAIT bit has the following meaning: Wait ='0': the interrupt falls immediately if signal crosses the selected threshold. 40/44 Doc 022768 Rev 3 A3G4250D Register description Wait ='1': if signal crosses the selected threshold, the interrupt falls only after the duration has counted a number of samples at the selected data rate, written into the duration counter register. Figure 19. Wait disabled Figure 20. Wait enabled Doc 022768 Rev 3 41/44 Package information 8 A3G4250D Package information In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK(R) packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at www.st.com. ECOPACK is an ST trademark. Figure 21. LGA-16: mechanical data and package dimensions Dimensions A1 1.100 A2 0.855 A3 0.200 d 42/44 0.300 D1 3.850 4.000 4.150 E1 3.850 4.000 4.150 L2 1.950 M 0.100 N1 0.650 N2 0.975 P1 1.750 P2 1.525 T1 0.400 T2 0.300 k 0.050 Doc 022768 Rev 3 LGA-16 (4x4x1.1 mm3) Land Grid Array Package A3G4250D 9 Revision history Revision history Table 66. Document revision history Date Revision Changes 02-Feb-2012 1 Initial release. 08-Feb-2012 2 Updated notes in Table 4: Mechanical characteristics. 14-Feb-2012 3 Updated Figure 21: LGA-16: mechanical data and package dimensions. Doc 022768 Rev 3 43/44 A3G4250D Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST's terms and conditions of sale. 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