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Quadrature squarewave generator
3

Quadrature squarewave generator

Quadrature squarewave generator

(OP)
I need a CMOS circuit that will give me quadrature squarewave ouputs. Any suggestions?

RE: Quadrature squarewave generator

A PIC is the standard solution. Their 8-leggers come to mind. What frequency or frequency range do you need? There are lots of app notes on the web. Make google your friend.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Quadrature squarewave generator

You really want a 2-bit gray code generator.  Xilinx has a nice N-bit generator VHDL template in their ISE software that is a free download:  

Gray code w/ CE and async active high reset

-- Usage of Asynchronous resets may negatively impact FPGA resources
-- and timing. In general faster and smaller FPGA designs will
-- result from not using Asynchronous Resets. Please refer to
-- the Synthesis and Simulation Design Guide for more information.
<next_binary_count> <= <binary_count> + 1;
  
process(<clock>,<reset>)
begin
   if ( <reset> = '1') then
      <binary_count> <= (others => '0');
      <gray_count> <= (others =>'0');
   elsif ( <clock>'event and <clock> ='1') then
      if <clock_enable>='1' then
         <binary_count> <= <next_binary_count>;
         <gray_count> <= (('0' & next_binary_count(<width-1> downto 1)) XOR <next_binary_count>);
      end if;
   end if;
end process;
 
        
You can simplify this down to a two bit counter and a couple of XOR gates if you want it in CMOS hardware.  

John D
 

RE: Quadrature squarewave generator

You may get perfect pulses of up to 200kHz with a PIC 10F200, SMD (SOT-23) pkg.

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