3.3v to 5v level translation

Thread Starter

garch

Joined Aug 23, 2008
24
Hi,

I would like to use a 3.3v parallax propeller microcontroller to drive a large high torque Futabo servo. I wanted to know:

(1) How to perform a 3.3v to 5v level translation (e.g. like a MAX3000 IC)
(2) How to drive such a high load (e.g. 1A @ 5v) from the microcontroller.

Any help would be greatfully appreciated.

Thanks

Garch
 

Papabravo

Joined Feb 24, 2006
18,834
The best solution that I have found is devices that work with Vcc from 1.65V to 5.5V and have TTL thresholds. So a 5V signal driving a device with Vcc at 3.3 Volts will define a low as less than 0.8V and a high as greater than 2.0V and will be toleraant of 5V on its input.

Similarly a device with Vcc at 5V will define a low as less than 0.8V and a high as greater than 2.0V.

For driving higher current loads you can use a BJT or a logic level MOSFET. Each method has advantages and disadvantages.
 

THE_RB

Joined Feb 11, 2008
5,438
The Futaba servos should work fine with control pulses of 0v-3v. So you can control it direct from the microcontroller pin.

As for the 1 amp power wire to the servo, just put a switch on it or connect it direct to the battery etc. When the microcontroller stops sending control pulses the servo will shut down and only draw about 7mA or so from the supply.
 
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