LMX2594: t1 time

hosoki tatsuya

Prodigy 210 points

Part Number: LMX2594
Other Parts Discussed in Thread: PLLATINUMSIM-SW

When using the SYNC pin
Please tell me the time of t1 when synchronizing multiple devices.

Data sheet
7.3.10.1 General Concept
Is it determined by the MASH_RST_COUNT value?

Although it is the default 50000 count, how many seconds is one count?

over 6 years ago

0 Dean Banerjee over 6 years ago

TI__Mastermind 28021 points

Tatsuya-san,

The delay due to MASH_RST_CNT is in state machine clock cycles. I don't see this description in the datasheet, but it is in the TICSPro software. A state machine clock cycle is Fosc/2^CAL_CLK_DIV. Fosc is the input reference frequency.

MASH_RST_CNT should be set to be about 4xPLL Lock time.

If in integer mode, you don't need MASH_RST_CNT. However, realize that if FCAL_EN=1, then toggling the SYNC pin or VCO_PHASE_SYNC bit will cause the VCO to re-calibrate.

Regards,
Dean

0 hosoki tatsuya over 6 years ago in reply to Dean Banerjee

Prodigy 210 points

Please tell me the time to lock the PLL.(LMX2594)

About LMK 04208 Please also tell me the PLL lock time.

0 Dean Banerjee over 6 years ago in reply to hosoki tatsuya

TI__Mastermind 28021 points

Tatsuya-san,

This depends on many factors, but can be simulated with the PLLatinum Sim tool at ti.com/tool/PLLATINUMSIM-SW.

The VCO can calibrate under 50 us and then the analog loop needs to settle. This is all modeled by the PLLatinum Sim tool.

Regards,
Dean

0 hosoki tatsuya over 6 years ago in reply to Dean Banerjee

Prodigy 210 points

Thank you very much.
I will see it.

Clock & timing

Clock & timing forum

LMX2594: t1 time