200kHz/100kHz 50% exact PWM generator
Colin J. Tuck ( Snr VP Global Corporate Engineering )
Power electronics IP at pwrtrnx.com
Sometimes you need a 50% pwm - and maybe also it's anti-phase complement - and you only have, say, the spare half of an 4013 ( or similar low voltage D type flip flop ) to work with.
[ Note: using just the LHS of the above ckt - 4013A only - you get a square 200kHz pwm and it's complement. Clock is 400kHz ]
Shown above the /Q output of the LHS 4013A is fed to another D type flip flop, 4013B, giving a very square 100kHz on the outputs of 4013B - buffered by the CD4050B - for more drive capability.
The 200kHz outputs of the 4013A are phase locked to the 4013B - which can be rather useful.
Adjusting R7, C2, - R9 & R13, adjusts frequency.
An interesting, simple and useful circuit that can be scaled for Vcc and frequency.
another version - showing where to add say 10V zener for 15V operation:
Power Electronics Engineer, Inventor
4 个月LTSpice?