General Description

The CD4541BC Programmable Timer is designed with a

16-stage binary counter, an integrated oscillator for use

with an external capacitor and two resistors, output control

logic, and a special power-on reset circuit. The special features

of the power-on reset circuit are first, no additional

static power consumption and second, the part functions

across the full voltage range (3V–15V) whether power-on

reset is enabled or disabled.

Timing and the counter are initialized by turning on power,

if the power-on reset is enabled. When the power is

already on, an external reset pulse will also initialize the

timing and counter. After either reset is accomplished, the

oscillator frequency is determined by the external RC network.

The 16-stage counter divides the oscillator frequency

by any of 4 digitally controlled division ratios.

Features

Available division ratios 28, 210, 213, or 216

Increments on positive edge clock transitions

Built-in low power RC oscillator (±2% accuracy over

temperature range and ±10% supply and ±3% over processing

@ < 10 kHz)

Oscillator frequency range ≈ DC to 100 kHz

Oscillator may be bypassed if external clock is available

(apply external clock to pin 3)

Automatic reset initializes all counters when power turns

on

External master reset totally independent of automatic

reset operation

Operates at 2n frequency divider or single transition

timer

Q/Q select provides output logic level flexibility

Reset (auto or master) disables oscillator during resetting

to provide no active power dissipation

Clock conditioning circuit permits operation with very

slow clock rise and fall times

Wide supply voltage range—3.0V to 15V

High noise immunity—0.45 VDD (typ.)

5V–10V–15V parameter ratings

Symmetrical output characteristics

Maximum input leakage 1 μA at 15V over full temperature

range

High output drive (pin 8) min. one TTL load