HP 45 High Precision Timer

[Sadsilence]

(09-21-2015 05:58 PM)cruff Wrote:  Just remembered that ceramic resonators can also be ordered for specific frequencies, but none of the standard stocked values are 784 kHz. :-(

Indeed, there are some in 455 kHz range or between 2 and 20 MHz. Moreover accuracy is only about 0.25-0.5%.

Today I come along some MEMS oscillators, programmable between 32 kHz and 100 MHz with a tolerance of only +- 20ppm and "only" 6 to 9 mA load. Voltage levels do not match with HP-45 supply and DFN housing is difficult to handle, but at least it is worth thinking about. Accuracy would increase even more and time consuming resistor selection of current solution is not necessary any more.