LMX2430: PLL with 0~2.4V output voltage at 3GHz

Danilo A.

Part Number: LMX2430
Other Parts Discussed in Thread: LMX2572

Hi Team,

Our customer is looking for PLL device which is similar to LMX243x series. The exact device that he needs is "A PLL, or any kind of device with pulsed voltage output with the following characteristics: 0V(gnd)~2.4V swinging voltage level, 3GHz output frequency". He would like to confirm if LMX2430TM would satisfy his requirements because the datasheet indicates that voltage swings from VOH=VCC-0.4V to VOL = 0.4V.

If the LMX243x doesn't fit his requirements, can you please suggest another device?

Regards,

Danilo

over 3 years ago

0 Noel Fung over 3 years ago

TI__Guru* 81510 points

Hi Danilo,

0V to 2.4V is the tuning voltage to the VCO. All PLL has a charge pump integrated, which will generate a pulsed current to the loop filter. The loop filter converts this current to voltage to lock the VCO.

With a passive loop filter, LMX2430 may be able to support 2.4V tuning voltage. To play safe, use active loop filter.

Below training site has some fundamental stuffs in PLL.

https://training.ti.com/ti-precision-labs-clocks-and-timing-phase-lock-loop-fundamentals?context=1139747-1140114-1140117

0 Jongha Park over 3 years ago in reply to Noel Fung

Prodigy 10 points

Thank you for your reply. I have additional question regards to this case.

I am currently setting up the measurement environment for my ADC chip, which has an integrated DLL that requires;

- 3GHz frequency

- 0V to 2.4V swing

- 50 ohm matched

external clock. But I lack of device such as pulse generators which exploits the required clock that has been stated above.

As LMX2430 does not have internal VCO integrated, I am looking for simpler device.

Would be there any device that operates with really simple integration?

(for example, device with 2~4GHz output according to Vtune input)

0 Noel Fung over 3 years ago in reply to Jongha Park

TI__Guru* 81510 points

Hi Jongha,

Did you mean you are looking for a PLL with integrated VCO, output frequency between 2 and 4GHz? If this is the case, we recommend LMX2572.

Or are you looking for a standalone VCO? We don't have standalone VCO.

Clock & timing

Clock & timing forum

LMX2430: PLL with 0~2.4V output voltage at 3GHz