Buffers

September 2020

Introduction     Reference & Dividers     TIC Circuit     Micro & Misc.

Input Buffers

The three input buffers isolate the 1 PPS input from the GPS receiver, and distribute it to where it is used: the Time Interval Counter, the rear panel socket (so the 1 PPS can be used for other purposes) and the panel LED. This isn't rocket science, by any means. Don't forget to place a 100 nF capacitor across the chip supply.


The Input Buffers circuit. (Click on the picture for a full-size diagram you can print).

Output Buffers

To provide plenty of drive without loading the circuit, each output is driven by two CMOS buffers in parallel. For even more drive, use a separate 100 Ohm resistor from each gate to the output socket. Wire from the board to the sockets with a pair of wires ripped from recycled ribbon cable. This will limit unintended radiation. Don't forget to place a 100 nF capacitor across the chip supply.


The Input Buffers circuit. (Click on the picture for a full-size diagram you can print).

Introduction     Reference & Dividers     TIC Circuit     Micro & Misc.

Copyright M. Greenman 2020. All rights reserved. Contact the author before using any of this material.