How about a generic voltage-controlled oscillator? IE: look up "VCO" on=20 Digikey -- they're fairly monolithic devices and generally require=20 little more than power, ground and a pot to control the voltage. Cheers, -Neil. On 10/12/2015 2:22 AM, David C Brown wrote: > The AD9850 sine wave generators are just that - sine wave generators. Th= ey > quote a square wave up to 5MHz which is not good enough. > > On 12 October 2015 at 03:33, Bob Blick wrote: > >> Hi David, >> >> Have you looked the plethora of AD9850 DDS sinewave generators? They >> have a comparator for squarewave output. I don't know what your spec is, >> but you could put a toggling flip-flop on the comparator output if you >> need better duty cycle accuracy than the comparator itself (if you can >> lose the upper octave). >> >> Best regards, Bob >> >> On Sun, Oct 11, 2015, at 11:04 AM, David C Brown wrote: >>> I am looking for a module to generate logic level square wave up to at >>> least 20MHz (50 would be better) within a $100 budget. There are a >>> number >>> of items on eBay but none have them seem to have a proper spec. Any >>> recommendations from experience? >>> >>> -- >>> __________________________________________ >>> David C Brown >>> 43 Bings Road >>> Whaley Bridge >>> High Peak Phone: 01663 733236 >>> Derbyshire eMail: dcb.home@gmail.com >>> SK23 7ND web: www.bings-knowle.co.uk/dcb >>> >> -- >> http://www.fastmail.com - Does exactly what it says on the tin >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .