Multi-Function Frequency Meter

EE 46 December 1987 MULTI-FUNCTION FREQUENCY METER An advanced, versatile and user-configurable test instrument capable of accurate measurement of frequency, frequency ratio and time interval. In addition to all this, it can be used as a period and event counter. The multi-function test instru- ment described here is based on the 8-digit counter/timer IC Type ICM7226B from Intersil (GE/RCA). This chip combines all the functions expected from a good and versatile counter, and requires very few external components. The chip handles frequency measurement from DC to 10 MHz, period measure- ment from 0.5 ps to 10 s, unit counting up to 10 million events, frequency ratio measurement, and time interval measurement. The inputs of the proposed in- strument can accept a wide range of alternating (analogue) voltages as well as digital pulses at TTL or CMOS levels. Circuit description The circuit diagram of the fre- quency meter is given in Fig. 1. It would be beyond the scope of this article...