7-segment display driver (CB20551E)

We found this circuit in English documentation from 1996 for PCs. The circuit is for common cathode display.

PLL 565 (CB4231E)
This is a typical application circuit of a 565 PLL. The circuit is suitable for selecting a 67 kHz...
High-Pass Filter Using Operational (MSB044E)
The circuit show and simulated in the MultiSIM BLUE is a high pass filter using a 741 operational...
Locked Output Detector (CB4814E)
We found this circuit in a Popular Electronics of the 90s. Its purpose is to detect when it locks...