PA MMZ09332BT1 Power Down Control Not working

[guanchoonlim]

Hi. I am  using NXP freescale MMZ09332BT1 as my transmit PA. This PA has a power down control to turn ON/OFF the RF power.   For RF BIAS ON,  the voltage on Power Down pin should be 0V. For RF BIAS OFF,  the power down voltage should be 1.4 to 2V.

However,  when I first power up the PA (+5V),  and toggle the PDC pin ,  there is no change in my +5V supply current!!  It seems that the PA is not biased properly!!!

To meet the Bias ON/OFF voltage range,  I am buffering my PA control signal with a inverter logic (powered by 2V VDD).  I want to ensure I meet the BIAS requirement stated in the PA datasheet (page 2).

Do anyone or any NXP technical support team members out there have any experience on this?   I am stuck and don't know how to proceed.

Thanks

Lim Guan Choon

email:lguancho@loop-electronics.com.sg

[andrei_skok]

Please tell me if you still have this problem

[guanchoonlim]

Hello, Skok. I have cleared the power control issue. It was a PCB layout issue which results in the Bias Voltage not being supplied to PA. My circuit (input and output matching networks) was based on the datasheet 400 to 500MHz application circuit, though my operating frequency is 280 to 300MHz. I got about 28 to 29dBm RF output at 330MHz (My application requirement is 32dBm @+5V). When I tested my circuit at 380MHz, I got about 32dBm @ +5V. I had opened a new private application support case with NXP , request for loadpull impedance data at 280 to 380MHz.

Are you able to help regarding the loadpull info? Sorry, as my company does not own any impedance stub tuners to perform such loadpull test ourselves.

I believe the low RF output power are due to the input & output mismatch the PA is facing (It is better much at 380MHz, probably due to the fact that the matching elements are tuned to 400 to 500MHz).

Regards

Lim Guan Choon

LOOP Electronics Pte Ltd

Blk 5012 Ang Mo Kio Ave 5

#04-04A, TECHPlace II

Singapore 569876

DID: 64563367

H/P: 94304810

Fax: 64560687