CD4541BC.pdf

The CD4541BC Programmable TImer is designed with a16-stage binary counter, an integrated oscillator for usewith an external capacitor and two resistors, output controllogic, and a special power-on reset circuit. The special featuresof the power-on reset circuit are first, no addiTIonalstaTIc power consumpTIon and second, the part functionsacross the full voltage range (3V–15V) whether power-onreset is enabled or disabled.Timing and the counter are initialized by turning on power,if the power-on reset is enabled. When the power isalready on, an external reset pulse will also initialize thetiming and counter. After either reset is accomplished, theoscillator frequency is determined by the external RC network.The 16-stage counter divides the oscillator frequencyby any of 4 digitally controlled division ratios.Featuresn Available division ratios 28, 210, 213, or 216n Increments on positive edge clock transitionsn Built-in low power RC oscillator (±2% accuracy overtemperature range and ±10% supply and ±3% over processing@ < 10 kHz)n Oscillator frequency range » DC to 100 kHzn Oscillator may be bypassed if external clock is available(apply external clock to pin 3)n Automatic reset initializes all counters when power turnsonn External master reset totally independent of automaticreset operationn Operates at 2n frequency divider or single transitiontimern Q/Q select provides output logic level flexibilityn Reset (auto or master) disables oscillator during resettingto provide no active power dissipationn Clock conditioning circuit permits operation with veryslow clock rise and fall timesn Wide supply voltage range—3.0V to 15Vn High noise immunity—0.45 VDD (typ.)n 5V–10V–15V parameter ratingsn Symmetrical output characteristicsn Maximum input leakage 1 mA at 15V over full temperaturerangen High output drive (pin 8) min. one TTL load