BUY HEF4001 https://www.utsource.net/itm/p/225721.html
Quadruple 2-input NOR gate
Description: Quad 2-Input NOR Gate Features: - Low power Schottky - High noise immunity - Inputs compatible with TTL and MOS logic - Outputs capable of driving 10 LSTTL loads - Direct replacement for 74LS00 - Maximum input current of 1 μA at 18V over full package temperature range - Maximum input diode current of 200 nA at 18V - Low input offset voltage Applications: - High speed logic - Clock generation - Pulse generation - Data transmission - Data conversion - Interface circuits - Timing circuits - Digital logic systems (For reference only)