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.
Products containing the "CD4541B" keyword are: CD4541BCM , CD4541BCM , ZMM5263B , CD4541BCM,2SB789-R,MT625 , CD4541BCMX , CD4541BCMX , CD4541BCMX(PBFREE) , CD4541BCN , CD4541BD , CD4541BE , CD4541BE , CD4541BE , SC431CSK , CD4541BEE4 , CD4541BEE4 , CD4541BEG4 , CD4541BEX , CD4541BF , CD4541BF/3A , CD4541BF3A , CD4541BFX , CD4541BMData sheet acquired from Harris Semiconductor
Status | ACTIVE |
SubFamily | Rate multiplier/frequency divider/timer |
Technology Family | CD4000 |
VCC | 18 |
Bits | 1 |
Voltage | 10 |
F @ nom voltage | 8 |
ICC @ nom voltage | 0.3 |
tpd @ Nom Voltage | 10000 |
Rating | Catalog |
Operating temperature range | -55 to 125 |
Package Group | PDIP|14 |
Package size: mm2:W x L (PKG) | See datasheet (PDIP) |
Approx. price | 0.11 | 1ku |