MPU9250 gyrcoscope raw data has a large drift when device is stationary

Hi
I'm new for MPU9250. I want to use it to do some applications about the attitude angle. I found there are a lot of noise in the gryscrope ouput when the MPU9250 is in stationary, about ±2dps (see attached figure). I have measured the vcc ripple wave amplitude. It is in the range 20mv.
Here are my settings:
PWR_MGMT_1 : 0x03
INT_PIN_CFG: 0x10
INT_ENABLE: 0x00
PWR_MGMT_2: gyroscope & accel
SMPLRT_DIV: 0
Gyroscope Full scale is 2000 dps
Accel Full scale is 8G
DLPFs(41Hz) are enabled for both gyroscope and accel.
SPI interface.