VD5377 datasheet(18/88 Pages) STMICROELECTRONICS

18 / 88 page

System overview

VD5377

18/88

Doc ID 022952 Rev 2

4.1

MANUAL power management

Manual power mode is the basic mode of the VD5377. After initialization, the sensor

remains in MANUAL RUN mode even when no motion activity is detected. The host can use

the external POWERDOWN or STANDBY signals to achieve lower current consumption.

•

STANDBY pin(a) (active high): if set, the system goes into low power STANDBY mode

at the end of the current frame. Typical power consumption in STANDBY mode is

shown in Table 8 on page 19. The internal clock and motion engine are switched off

and so the VD5377 does not respond to any I2C communication and no motion activity

is detected. All register settings are maintained in this state, so when STANDBY is de-

asserted the system immediately resumes in RUN mode.

•

POWERDOWN pin: if set, this signal immediately disables the internal 1.8 V core

regulator. After power down, the system needs to be re-initialized. Power consumption

is typically <1 µA in this state.

Figure 7. Manual power mode flow diagram

a. During initialization, the user must set the use_standby_pin register bit (system_config 0x05 bit 4) to 1 to

enable the STANDBY pin function otherwise it is ignored.

MCU BOOT

SW STBY

MANUAL

RUN

MODE

AUTOMATIC

host_config_done = 1

automatic = 0

host_config_done = 1

automatic = 1

POWERDOWN

STANDBY

MANUAL POWER MODE

STANDBY=1

STANDBY=0

POWERDOWN=1

POWERDOWN=0

POWERDOWN=1

POWER UP

VD5377 数据表(PDF) 18 Page - STMicroelectronics

VD5377 数据表(HTML) 18 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88

数据表下载