Si4421
Logic connections between power control bits:
enable
power amplifier
et
es
Edge
detector
start TX
clear TX latch
enable
RF synthesizer
enable
power amplifier
enable
RF synthesizer
VCO and
enable
RF front end
PLL
start TX
er
enable
RF front end
clear TX latch
TX latch
enable baseband
circuits
enable
crystal oscillator
Crystal
oscillator
I/Q
demod
enable baseband
circuits
ebb
Digital signal
processing
enable crystal
oscillator
ex
clock and data out
Note:
? If both et and er bits are set the chip goes to receive mode.
? FSK / nFFS input are equipped with internal pull-up resistor. To achieve minimum current consumption do not pull this input
to logic low in sleep mode.
? To enable the RF synthesizer, the crystal oscillator must be turned on
? To turn on the baseband circuits, the RF synthesizer (and this way the crystal oscillator) must be enabled.
? Setting the er bit automatically turns on the crystal oscillator, the synthesizer, the baseband circuits and the RF fronted.
? Setting the et bit automatically turns on the crystal oscillator, the synthesizer and the RF power amplifier.
Clock tail feature: When the clock output (pin 8) used to provide clock signal for the microcontroller ( dc bit is set to 0), it is possible
to use the clock tail feature. This means that the crystal oscillator turn off is delayed, after issuing the command (clearing the ex bit)
192 more clock pulses are provided. This ensures that the microcontroller can switch itself to low power consumption mode. In order
to use this feature, a Status Read Command (page 27) must be issued before the ex bit set to zero. If status read was not performed
then the clock output shuts down immediately leaving the microcontroller in unknown state.
Automatic crystal oscillator enable/disable feature: When an interrupt occurs, the crystal oscillator automatically turns on –
regardless to the setting of the ex bit – to supply clock signal to the microcontroller. After clearing all interrupts by handling them
properly (see the Interrupt Handling section, page 28) and performing Status Read Command , the crystal oscillator is automatically
turned off. The clock tail feature provides enough clock pulses for the microcontroller to go to low power mode. Due to this automatic
feature, it is not possible to turn off the crystal by clearing the ex bit if any interrupt is active. For example, after power on the POR
interrupt must be cleared by a status read then writing zero to the ex bit will put the part into sleep mode. Very important to clear all
interrupts before turning the ex bit off because the extra current required by running crystal oscillator can shorten the battery life
significantly.
Disabling the clock output (bit dc =1) turns off both the clock tail and the automatic crystal oscillator enable/disable feature, only the
ex bit controls the crystal oscillator (supposing that both the er and et bits are cleared), the interrupts have no effect on it.
16
相关PDF资料
F2M03G-KIT-1 KIT EVAL G MOD SNGL (NO OEM BRD)
F2M03M-KIT-1 KIT EVAL M MOD SNGL (NO OEM BRD)
FA10323_K2S-W LENS FOR LUXEON K2
FA10539_SSS-W LENS FOR SEOUL P4
FA10643_TINA-M LENS FOR GOLDEN/PLATINUM DRAGON
FA10644_TINA-D LENS TINA DIFF 6.5DEG
FA10666_CXP-D LENS CXP DIFF SQ 16DEG
FA10678_CMC-SS LENS CMC SMOOTH SPOT MC-E
相关代理商/技术参数
EZLC-4421HB 制造商:Silicon Laboratories Inc 功能描述:EZLink 4421 development kit, 868/915MHz
EZLC-4421LB 制造商:Silicon Laboratories Inc 功能描述:EZLink 4421 development kit, 433MHz
EZLC4431B1-D434 功能描述:射频开发工具 EZLink Kit F930 Si4431 Rev B1 434MHz RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
EZLC4431B1-D868 功能描述:射频开发工具 EZLink Kit F930 Si4431 Rev B1 868MHz RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
EZLC-4432 HB 功能描述:射频开发工具 EZLink Fast Prototype Kit Hiband RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
EZLC-4432 HB/LB KIT 制造商:Silicon Laboratories Inc 功能描述:
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EZLC4432B1-D470 功能描述:射频开发工具 EZLink Kit F930 Si4432 Rev B1 470MHz RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V