MC14541BDT

可编程定时器 Programmable Timer

Programmable Timer

  The MC14541B programmable timer consists of a 16−stage binary counter, an integrated oscillator for use with an external capacitor and two resistors, an automatic power−on reset circuit, and output control logic.

  Timing is initialized by turning on power, whereupon the power−on reset is enabled and initializes the counter, within the specified VDD range. With the power already on, an external reset pulse can be applied. Upon release of the initial reset command, the oscillator will oscillate with a frequency determined by the external RC network. The 16−stage counter divides the oscillator frequency fosc with the nth stage frequency being fosc/2n

Features

•Available Outputs 28, 210, 213 or 216

•Increments on Positive Edge Clock Transitions

•Built−in Low Power RC Oscillator ±2% accuracy over temperature range and ±20% supply and ±3% over processing at < 10 kHz

•Oscillator May Be Bypassed if External Clock Is AvailableApply external clock to Pin 3

•External Master Reset Totally Independent of Automatic Reset Operation

•Operates as 2n Frequency Divider or Single Transition Timer

•Q/QSelect 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

•Automatic Reset Initializes All Counters On Power Up

•Supply Voltage Range = 3.0 Vdc to 18 Vdc with Auto Reset

  Supply Voltage Range = Disabled Pin 5 = VDD

  Supply Voltage Range = 8.5 Vdc to 18 Vdc with Auto Reset

  Supply Voltage Range = Enabled Pin 5 = VSS

•Pb−Free Packages are Available

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