recomendation for microcontroller programmed DC-DC suited for power amplifier sequencer

Hi,

I´m not sure: when you say (for example) "set VG2 = +5V and turn ON"...
does this mean you want to ramp up the voltage from 0 to 5V, or do you want to switch it within no time from 0V to 5V?

If ramp: give some timing.

There are power supplies with "adjustable" outputs .. for ramp up/down
There are power supplies with "enable" .. to switch ON/OFF

Klaus

PSOC, this uses small amount of its resources, its single chip solution (except for external FETs
to switch the actual power) :



This uses a small amount of onchip resources, many more available for other tasks.

Whats onchip (multiple copies in almost all cases) :



Chip is SOC, so if all you want is just sequencer probably this is overkill.

Sequencer and monitor config wizards :




The resources on chip are called "components", and I attached the sequencer and monitor component
datasheet to look at. You drag and drop them onto canvas, config, and use their associated
api lib to code behaviour and timing.





Regards, Dana.

If we're still on the RF element controller subject then
I suspect that you do not want to be using a DC-DC
for electromagnetic filth reasons. All the active bias
versions I've been asked for only needed an op amp
(and not a very good one). However my requirements
did not require or envision messing with the RF power
supply - and anything pulsed or chirped mode probably
does not want to out-wait a power supply soggy
switching interval.

Drain switch and a wee bit of very good close-in C is
a much more normal thing.

Be sure you really need this elaborateness, I suspect
you do not.

Hello ,i need to build a sequencer for this amplifier.
I need to supply DC voltages at a certain time.One good option i thought is to use a micro controller.
What DC supplying device you reccomend which whould be suited for power amplifier and i could control it with a MCU.
I cannot use A/D because i need to deliver also DC current thre the drain of the power amplifier.
What device do you reccomend for the task?
Thanks.


UPDATE:
Maybe this device is good ?

What do you expect the effect of DC-DC chop on the RF
lineup will be? I expect "not good". You would at least want
all that in "some other can" and filtered to death before it
gets out of said can. Oh, and the input supply is going to
receive a bunch of conducted emissions too.

A simple active bias controller with drain switch and gate
feedback (to servo the average drain current, a common
goal) is what the application wants. Make somebody else
provide clean power and just switch the drain on, gate
ramps from pinched-off to setpoint, badda-bing.

Hello Dick_freebird,given the table order below and the fact that i want to do the sequence using a microcontroller.
could you reccomend a spesific active bias controller with drain switch which could be alternative to DC-DC?
Thanks.

Hello Dick_freebird,In the maual bellow QORVO used DC-DC for a sequencer.
Do you have a manual just like thick which biases amplifier but uses a microcontroller?
Thanks.

There are regulators with POWER GOOD output and ENABLE input. You could use 3 of those, wired in the correct order.

Hello Barry,I got this good QORVO manual shown below it uses a combination of regulators and a comporator.
all the component there are analog
LT1716 -analog comparator
LTC1261LCS8-4 - negative generator
LT1761-BYP- analog regulator
Could you reccomend me similar components which could do the same method using a microcontroller?
Thanks.

Do you want detection of excess current thrum MOSFET or is that a dont care ?

Regards, Dana.

Hello Dana, First I want to have a basic logical skeleton to understand how this thing will function.
Regarding the LTC1261LCS8 In order to stick with the QORVO manual can I Turn on and off the voltage regulator with a MCU using SHDN pin ?
The SHDN manual is shown below ,Is there MCU periphery trick in which i could turn ON and OFF this regulator?
What is the proper way to turn it on and off using MCU?
Thanks.

Yes per your post of :



Just have pin on micro set high, simple........is micro 3V or 5V ?

Regards, Dana.

Hello Dana,I want to use ESP8266 which is 3.3V GPIO.
Suppose i want to turn this device on so i send GPIO pin into logical 1 which is "3.3"
However the device working when the SHDN is floating.
How do i connect the GPIO pin to the LTC1261L so i could turn it ON and OFF with GPIO pin?
Could you make some visual schematics so i'll the method of doing that? (if its possible)
Thanks.

If you are supplied clean drain voltage and a gate bias rail (typ -5V-ish
to allow regulation to -3V typ pinchoff) then all this elaborateness is
not needed, you can do it much simpler. Some of the complexity you
keep trying to add is going to pollute your RF lineup, and for what?

I don't think you are giving enough thought to what resources you
will be provided, and the qualities that the so-managed RF chain
must deliver. These will inclulde time-to-settled turnon and
time-to-dead-flat turnoff (neither one a selling point of switchers
where you need big high quality C to get the ripple (your phase
noise EMI aggressor) down "into the noise" (yeah, right) thus
ensuring ms "blockout" intervals on any cycling. My space radar
customers wanted microseconds and not many, for TX <-> RX
flip (like a radar does). They sent clean stable voltage to the panel
and managed elements in subpanel quads (my chips were "quad
element controllers"). They would even stop the serial clock during
active RX or TX intervals, everything was about noise and quick
mode transitions.

A continuously-biased RF chain would need even less messing-with.
But obviously "continuous" is not the plan because here we are. So
I suggest you think a bit more about just how often and how fast and
how clean the power up and power down need to be, along with what
demands critera like phase noise and splatter impose on the supply
steady state and transitions. Then you can determine whether any of
these switcher-based approaches offer anything worth their downsides
(BOM complexity, conducted and radiated emissions / susceptibility,
time-to-complete, overshoots, faults, ...).

yefj said:

Hello Dana,I want to use ESP8266 which is 3.3V GPIO.
Suppose i want to turn this device on so i send GPIO pin into logical 1 which is "3.3"
However the device working when the SHDN is floating.
How do i connect the GPIO pin to the LTC1261L so i could turn it ON and OFF with GPIO pin?
Could you make some visual schematics so i'll the method of doing that? (if its possible)
Thanks.

NodeMCU ESP8266

NodeMCU ESP8266

components101.com

Click to expand...

The min "1" level of the SHDN is 2 V, so just directly connect ESP8266 GPIO pin
to it.

Regards, Dana.

Hello Dana,Shdn needs to be floating . How putting 3.3v will make Shdn to float ?

Why floating if its supposed to be under control of micro ?

This thread went off the rails about 10 posts ago. I'm out of here

Hello Dana , Sorry for the missunderstanding.
The QORVO manual doesnt use a MCU, i want to implement this manual with an MCU.
So i asked regarding controlling LTC1261LCS8 SHDN as turn on and OFF.
If you say that I cannot control LTC1261LCS8 using SHDN, Is there are method you recommend to control this componnent?
Or you reccomend other more suitable components?




UPDATE:
Hello Dana,So if i put GPIO '0' to the SHDN which is 0 volts to the SHDN pin why does it means that the SHDN pin will be connected to GND?
COuld you please make some drawing so i'll understand the logic?
Thanks.