HEF4541B

应用领域

The HEF4541B is a programmable timer. It consists of a 16-stage binary counter, an integrated oscillator to be used with external timing components, an automatic power-on reset and output control logic. The external components RTC and CTC determines the frequency of the oscillator within the frequency range 1 Hz to 100 kHz. An external clock signal at input RS can replace the oscillator. The timer advances on the positive-going transition of RS. A LOW on the auto reset input (AR) and a LOW on the master reset input (MR) enables the internal power-on reset. A HIGH level at input MR resets the counter independent on all other inputs. Resetting, disables the oscillator to provide no active power dissipation.

A HIGH at input AR turns off the power-on reset to provide a low quiescent power dissipation of the timer. The 16-stage counter divides the oscillator frequency by 28, 210, 213 or 216 depending on the state of the address inputs (A0, A1). The divided oscillator frequency is ava