lmv7219-mdc National Semiconductor Corporation, lmv7219-mdc Datasheet - Page 10

• Manufacturer Part Number: lmv7219-mdc
• Description: 7 Nsec, 2.7v To 5v Comparator With Rail-to Rail Output
• Manufacturer: National Semiconductor Corporation

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Crystal Oscillator
A simple crystal oscillator using the LMV7219 is shown
below. Resistors R1 and R2 set the bias point at the com-
parator’s non-inverting input. Resistors R3, R4 and C1 sets
the inverting input node at an appropriate DC average level
based on the output. The crystal’s path provides resonant
positive feedback and stable oscillation occurs. The output
duty cycle for this circuit is roughly 50%, but it is affected by
resistor tolerances and to a lesser extent by the comparator
offset.
FIGURE 5. Crystal Oscillator
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IR Receiver
The LMV7219 is an ideal candidate to be used as an infrared
receiver. The infrared photo diode creates a current relative
to the amount of infrared light present. The current creates a
voltage across RD. When this voltage level cross the voltage
applied by the voltage divider to the inverting input, the
output transitions.
FIGURE 6. IR Receiver
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