DM-COP8/20D National Semiconductor, DM-COP8/20D Datasheet - Page 202

• Manufacturer Part Number: DM-COP8/20D
• Description: CABLE FOR DEBUG MODULE 20-DIP
• Manufacturer: National Semiconductor

Specifications of DM-COP8/20D

• Accessory Type: 20-DIP Target Cable
• For Use With/related Products: MetaLink Debug Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *DM-COP8/20D

This section describes several applications that use the 16-bit on-chip timer: speed
measurement with the Input Capture mode and an external event counter with the
External Event Counter mode.
4.4
The 16-bit timer can be used in any of the following applications:
4.4.1
The first example illustrates how a rudimentary D-A converter may be built by using the
timer. By controlling the values in the register the user can control the frequency and
duty cycle of the resultant waveform. The voltage at the capacitor is directly proportional
to the duty cycle. Increasing the T
to increase the analog voltage, whereas increasing the T
frequency constant serves to decrease the analog voltage.
4.4.2
In the second example, the PWM output provides servo control for the DC motor. By
varying the ON and OFF times (varying duty cycle) and varying the cycle time, the DC
motor speed is controlled.
4-10
TIMER PWM APPLICATIONS
COP8SAx7 APPLICATION IDEAS
Rudimentary D-A Converter
PWM Motor Control
PWM
COP8SAx7
COP888
PWM
PWM
Interface
TRIAC
D/A Converter
Driver
Figure 4-5 Timer PWM Applications
R
D.C. Motor
Feedback
ON
C
120Vac
60 Hz
value while holding the frequency constant serves
Load
T
ON
OFF
Analog Signal
T
TRIAC
Control
value while holding the
OFF
Output
PWM