S1F76620 Series
FUNCTIONAL DESCRIPTIONS
CR Oscillator
S1F76620 has a
OSC1 | (Note 1) |
ROSC
OSC2
Voltage Conversion Circuit
The voltage conversion circuit uses clocks generated in the CR oscillator to double the input supply voltage VDD.
In case of 2 times
When GND is 0 and VDD is 5, the relations between input/output and voltage are as shown below:
CAP1=2VDD=10V
S1F76620 | Series |
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Note 1 |
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| VDD=5V | |
Since the oscillation frequency varies with wiring ca- | |||||||||||||
pacitance, make the cables between the terminals OSC1 |
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and OSC2 and ROSC as short as possible. | GND=0V | ||||||||||||
When setting the external resistor ROSC, find ROSC suit- |
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able for fOSC that brings about the maximum efficiency |
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from characteristics graph (9) and (10). The relations |
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between ROSC and fOSC in characteristics graph (1) are |
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expressed approximately with the following formula as |
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far as the |
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straight portion (500kΩ < ROSC < 2MΩ) is concerned: |
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| ROSC = A • (1/fOSC) |
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(A : Constant, When GND is 0V and VDD is 5V, A is |
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approximately 2.0 × 1010 (I/F).) |
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So, the ROSC value can be obtained from this formula. |
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(Recommended oscillation frequency : 10kHz to 30kHz |
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(ROSC : 2MΩ to 680kΩ)) |
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When the external clock operates, make the pin OSC2 |
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open as shown below and input the 50% duty of the ex- |
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ternal clock from the pin OSC1. |
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| OSC1 |
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| External clock |
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| OSC2 |
| Open |
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S1F70000 Series Technical Manual
EPSON |