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CMOS Programmable Timer - High Voltage Type (20V Rating)


Package | PIN: PW | 14
Temp: M (-55 to 125)
Carrier: Cut Tape
Qty Price
1-9 $0.33
10-24 $0.29
25-99 $0.27
100-249 $0.23
250-499 $0.21
500-749 $0.16
750-999 $0.12
1000+ $0.11


  • Low Symmetrical Output Resistance, Typically 100 at VDD = 15V
  • Built-In Low-Power RC Oscillator
  • Oscillator Frequency Range . . . DC to 100kHz
  • External Clock (Applied to Pin 3) can be Used Instead of Oscillator
  • Operates as 2 N Frequency Divider or as a Single-Transition Timer
  • Q/Q\ Select Provides Output Logic Level Flexibility
  • AUTO or MASTER RESET Disables Oscillator During Reset to Reduce Power Dissipation
  • Operates With Very Slow Clock Rise and Fall Times
  • Capable of Driving Six Low Power TTL Loads, Three Low-Power Schottky Loads, or Six HTL Loads Over the Rated Temperature Range
  • Symmetrical Output Characteristics
  • 100% Tested for Quiescent Current at 20V
  • 5V, 10V, and 15V Parametric Ratings
  • Meets All Requirements of JEDEC Standard No. 13B, "Standard Specifications for Description of ’B’ Series CMOS Devices"

Data sheet acquired from Harris Semiconductor

Texas Instruments  CD4541BPWR

CD4541B 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 transitions and can also be reset via the MASTER RESET input.

The output from this timer is the Q or Q\ output from the 8th, 10th, 13th, or 16th counter stage. The desired stage is chosen using time-select inputs A and B (see Frequency Select Table).

The output is available in either of two modes selectable via the MODE input, pin 10 (see Truth Table). 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 2N. With the MODE input set to logic "0" and after a MASTER RESET is initiated, the output (assuming Q output has been selected) changes from a low to a high state after 2N-1 counts and 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 until 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 power-on reset, VDD should be greater than 5V.

The RC oscillator, shown in Figure 2, oscillates with a frequency determined by the RC network and is calculated using:

Where f is between 1kHz and 100kHz and RS and 2RTC.