Si4012-C1-GT Silicon Laboratories Inc, Si4012-C1-GT Datasheet - Page 12

• Manufacturer Part Number: Si4012-C1-GT
• Description: RF Transmitter 27-960 MHz RF Transmitter
• Manufacturer: Silicon Laboratories Inc

Si4012
4.4. Operating Mode Control
Transition Notes
State Descriptions
The Si4012 has six power modes, which are summarized below. Further details on the IC configuration in these
modes can be found in "5.1.5. COMMAND: CHANGE_STATE" on page 23.





12
1. Transition to any state (including SHUTDOWN) using the CHANGE_STATE command. Alternatively, transition to
2. If a CHANGE_STATE command to the XO TUNE state is issued (even if already in the XO TUNE state), then an XO
3. Transition to end state specified in the TX_START command or TX_STOP command.
4. If coming out of the SHUTDOWN via SMBus, an SMBus “wake-up” byte is required. This byte is discarded, and normal
SHUTDOWN—Lowest current consumption; the majority of hardware blocks are powered down.
STANDBY—Low power state with fast SMBus response.
SENSOR—Same as STANDBY, but the battery is measured periodically.
TUNE—Periodic tuning state. A tune is performed on any CHANGE_STATE to TUNE command and then
periodically based on the interval defined in TUNE_INTERVAL. This provides faster transition to TX. If XO is
enabled, XO will be used during tune operation.
TX—Transmission state.
SHUTDOWN using the SDN pin.
TUNE operation is carried out immediately. This enables close control of timing (fastest execution) for a subsequent
TX_START command. In the TUNE state, a tune operation is carried out in the interval specified in TUNE_INTERVAL.
SMBus communication can proceed after the power on reset (ipor) is asserted to the host.
SHUTDOWN
1
SMBus or
(NOTE 4)
SDN
SDN=1?
Yes
No
Figure 3. State Machine Diagram
NOTE1
STANDBY
SENSOR
2
3
CHANGE_STATE
NOTE1
CHANGE_STATE /
Rev 0.2
Tx_START
NOTE1, 2
XO in CHIP_CONFIG?
TUNE with XO
TUNE without
XO
5
4
Yes
No
NOTE1
TX_START
TX_START
NOTE1, 3
TX
6