- on Computers and microprocessors
- Published in issue 10/1988 on page 60
Simple 1.2 Ghz Prescaler For Frequency Meters
60 EE October 1988 Vin max. 20 V +5,7v ,40V f 10 nF 2 10 nF IC1 " 74 LS 00 TDB 7805 T BAW 76 UmI Uout nv lil ‚Ä¢ 10 pF I BAW 22 pFT I BAS 70/04 * leadless ceramic capacitor gate I Th_ gate 2 I 74 LS 390 or 74 HC 390 13 counter 880157 - 10 APPLICATION NOTES The contents of this column are based on information obtained from manufacturers in the electronics industry, or their representatives, and do not imply practical experience by Elektor Electronics or its consultants. SIMPLE 1.2 GHz PRESCALER FOR FREQUENCY METERS by R. Bonsch One problem with many frequency meters is that the maximum usable input frequency is limited to about 100 MHz. Decade prescalers are available to extend this frequency range upwards to about 1000 MHz, but they are notoriously expensive. The main benefits of the circuit described here are the relatively simple construction, good reproducibility, and low cost. The new Type SDA4212 prescaler from Siemens is remarkable for its high sensi- tivity and excellent la...