4538, 744538 Dual precision monostable multivibrator with Schmitt-trigger inputs. Retriggerable, resettable. For 74HC4538 the Cext pin may be grounded. +----------+ 1Cext |1 +--+ 16| VCC 1RCext |2 15| 2Cext /1RST |3 14| 2RCext 1TR |4 13| /2RST /1TR |5 4538 12| 2TR 1Q |6 11| /2TR /1Q |7 10| 2Q GND |8 9| /2Q +----------+ [This information is part of the GIICM] On 20010829 I inverted the polarity of the resets on pin 3 and 13 thanks to a tip of Andreas Ripken, Jaap