TECHNICAL DATA

IW4541B

Programmable Timer

High-Performance Silicon-Gate CMOS

Rev. 00

The IW4541B programmable timer consists of a 16-stage binary

counter, an oscillator that is controlled by external R-C components (2

resistors and a capacitor), an automatic power-on reset circuit, and output

control logic. The counter increments on positive-edge clock transitons

and can also be reset via the MASTER RESET input.

The output from this timer is the Q or not Q output from the 8th, 10th,

13th, or 16th counter stage. The desired stage is chosen using time-select

inputs A and B. The output is available in either of two modes selectable

via the MODE input, pin 10. When this MODE input is a logic “1”,the

output will be a continuous square wave having a frequency equal to the

oscillator frequency divided by 2

and after a MASTER RESET is initiated, the output (assuming Q output

has been selected) changes from a low to a high state after 2

remains in that state until another MASTER RESET pulse is applied or

the MODE input is set to a logic “1”.

Timing is initialized by setting the AUTO RESET input (pin 5) to

logic “0”and turning power on. If pin 5 is set to logic “1”, the AUTO RESET circuit is disabled and counting will not

start untill after a positive MASTER RESET pulse is applied and returns to a low level. The AUTO RESET consumes

an appreciable amount of power and should not be used if low-power operation is desired. For reliable automatic

ORDERING INFORMATION

IW4541BN Plastic

IW4541BD SOIC

• Operating Voltage Range: 3.0 to 18 V

• Maximum input current of 1 μA at 18 V over full package-temperature range; 100 nA at 18 V and 25°C

• Noise margin (over full package temperature range):

1.0 V min @ 5.0 V supply

2.0 V min @ 10.0 V supply

2.5 V min @ 15.0 V supply

PIN ASSIGNMENT

NC = NO CONNECTION

LOGIC DIAGRAM

PIN 7 = GND

PINS 4,11 = NO CONNECTION