SI4770-77-A20 Datasheet, PDF (46/54 Pages) Silicon Laboratories – HIGH-PERFORMANCE CONSUMER ELECTRONICS

Si4770/77-A20
8. Reset, Powerup, and Powerdown
Setting the RSTB pin low will disable analog and digital circuitry, reset the registers to their default settings, and
disable the bus. Setting the RSTB pin high will bring the device out of reset.
The powerup mode powers up the device and provides mode selection. Mode selections include the following:
 AM, FM reception (Si4770/77-A20 only).
 Crystal oscillator or reference clock input
A powerdown mode is available to reduce power consumption when the part is idle. Putting the device in
powerdown mode will disable analog and digital circuitry while keeping the bus active.
VIO₁
VIO₂
VD
VA
RSTB
SCL
SDA
100 µsec min
100 µsec min
POWER_UP Command
Figure 27. Startup Timing
46
Rev. 0.9