SCT1555 Datasheet | Zetex Semiconductors

DESCRIPTION These devices are precision timing circuits for generation of accurate time delays or oscillation. Advanced circuit design means that these devices can operate from a single battery cell with the minimum of quiescent current. In monostable mode time delays are controlled by a single resistor and capacitor network. In astable mode the frequency and du t y cy c l e c a n be a c c u r a t e l y an d independently controlled with two external resistors and one capacitor. The threshold and trigger levels are normally set as a proportion of VCC by internal resistors. These levels can be programmed by the use of the control input pin. When the trigger input reduces to a value below the trigger level, the flip-flop is set and the output goes high. With the trigger input above the trigger level and the threshold input above the threshold level, the flip-flop is reset ZSCT1555 and the output goes low. The reset pin has priority over all the other inputs and is used to start new timing cycles. A low on the reset input causes the flip-flop to reset forcing the output low. Whenever the output is forced low then the internal discharge transistor is turned on. FEATURES - - - - - - - 0.9V supply operating voltage guaranteed Pin connections parable with 555 series timers Very low quiescent current 74 µA SO8 and DIL8 packages Operating temperature range patible with battery technologies APPLICATIONS Portable and battery powered equipment Low voltage and low power systems SCHEMATIC DIAGRAM 8 VCC CONTROL 5 6 THRESH 2 TRIGGER 7 DISCHARGE 3 OUTPUT 4 RESET 1 GND 4-311 ZSCT1555 ABSOLUTE MAXIMUM RATINGS Supply Voltage Input Voltages (Cont, Reset, Thres, Trig) Output Current Operating Temperature Storage Temperature 9V 9V 100m A -20 to 100°C -55 to 150°C Power Dissipation (Tamb=25°C) DIL8 625m W SO8 625m W Remended Operating Conditions Supply Voltage 0.9V(min) 6V(max) Input Voltages 6V(max) (Cont, Reset, Thres, Trig) Output Current Sink 100m A(max) Source 150µA(max) ELEC...