Quadrature squarewave generator 3

[RICH535]

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

 

[Skogsgurra]

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

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[zappedagain]

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

 

[GonzaloEE]

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