Hello,
In the IWR1443 SWRS211 datasheet, there is a Device Wake-up Sequence figure 5-2, the Slicer Ref_Clk shows a 5ms Stabilization delay. Does the 5m delay for the slicer clock delay the bootup? If an external TCXO is used, can the 5ms delay be shortened in software? In a low power radar application would using the TCXO save power?
Hello in Figure 5-2 SWRS211 IWR1443 datasheet the 5msec Stabilization Delay is a combination of the crystal, internal circuit delay. This clock, typically 40Mhz must be stable before the continuation of bootup. Yes the slicer clock delay is before bootup.
If an external TCXO is used (approx 1v sine) it is AC coupled to CLKP. CLKM is connected to a bias string 1.8v to R1 to CLKM to R2 to GND.
In production devices, there will be two sections of software, Boot Rom to load the RSS (Radio SubSystem), and QSPI Flash to load the MSS (Master SubSystem) or MSS and DSS (DSPSubSystem), and patches.
If an external TCXO is used, there is an external crystal stabilization, then the internal circuit, it is typically less than 5ms. The final boot ROM software needs to be checked, currently there is not a software override for the 5ms delay.
In a low power radar application, the TCXO will consume more power than the passive crystal oscillator. In cases where higher precision, is desired over temperature, or in driving the 40Mhz clock to multiple mmWave Sensor devices, an external TCXO may still be desireable.
Regards,
Joe Quintal
