voltage switching
voltage switching
(OP)
Help!
I need a device that will detect a negative edge and output a negative pulse so that the voltage finishes in a high state.
Neo11
I need a device that will detect a negative edge and output a negative pulse so that the voltage finishes in a high state.
Neo11





RE: voltage switching
RE: voltage switching
1 C.
1.) input( from TTL) --- CAP.1
2.) CAP.2 --- R1.1 ---R2.1 --- output (to 1 TTL load)
3.) R1.2 --- gnd
4.) r2.2 ---Vcc
R1 = R2 = 1k
The output is normally vcc/2 (2.5 V). On the negative edge of the input the output drops below the "0" logic level (.8V) until the C discharges through the R-s bacl to original level.
The negative pulse is about R * C/4 long i.e. with 1Kohms and 1000pF in the range of 250nS.
<nbucska@pcperipherals.com>