
ON Semiconductor
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 Available
(Apply external clock to Pin 3)
• External Master Reset Totally Independent of Automatic Reset
Operation
• Operates as 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
• Automatic Reset Initializes All Counters On Power Up
• Supply Voltage Range = 3.0 Vdc to 18 Vdc with Auto Reset
Disabled (Pin 5 = VDD)
= 8.5 Vdc to 18 Vdc with Auto Reset
Enabled (Pin 5 = VSS)
• NLV Prefix for Automotive and Other Applications Requiring
Unique Site and Control Change Requirements; AEC−Q100
Qualified and PPAP Capable
• These Devices are Pb−Free and are RoHS Compliant