onsemi (Ansemi)

SOIC-16

Tube

48

The VHC123A is an advanced high-speed CMOS Monostable multivibrator fabricated in a silicon-gate CMOS process. It achieves high-speed operation similar to an equivalent bipolar Schottky TTL while maintaining CMOS low power consumption. Each multivibrator has a negative A and a positive B transition trigger input, both of which can be used as inhibit inputs. A clear input is also included, which if asserted low resets the one-shot operation. The VHC123A can be triggered on positive transitions of this clear input while A is held low and B is held high. The output pulse width is determined by this formula: PW = (Rx)(Cx); where PW is seconds, R is ohms, and C is degrees Fahrenheit. Rx and Cx limits are: External Capacitor, CxNo Limit External Resistor, Rx VCC = 2.0V, 5 kohm Min VCC > 3.0V, 1 kohm Min An Input protection circuit ensures that 0 to 7V can be applied to the input pin, Regardless of the supply voltage. This device can be used to interface 5V systems with 3V systems and both power systems, such as battery backup. This circuit prevents damage to the device due to mismatched supply and input voltages.