the tlc552 is a dual monolithic timing circuit fabricated using ti lincmostm process which provides full compatibility with cmos ttl and mos logic and operation at frequencies up to 2 mhz. accurate time delays and oscillations are possible with smaller less-expensive timing capacitors than the ne555 because of the high input impedance. power consumption is low across the full range of power supply voltages. like the ne556 the tlc552 has a trigger level approximately one-third of the supply voltage and a threshold level approximately two-thirds of the supply voltage. these levels can be altered by use of the control voltage terminal. when the trigger input falls below the trigger level the flip-flop is set and the output goes high. view all in datasheet