Specifications

EPSON 2–17
SED1200 Series
SED1200
Series
APPLICATION NOTES
Display Oscillator
The SED1200 has an internal oscillator to generate the
timing signals required for the LCD display.
If the internal oscillator is used, connect the feedback
resistor Rf as shown in figure 3. The feedback resistor
leads must be kept as short as possible to reduce stray
capacitance and the possibility of crosstalk between the
oscillator and adjoining signals.
If an external clock is used, connect it to OSC1, as shown
in figure 4.
The relationship between the oscillator frequency and
the LCD drive frame frequency is
f
FR = fOSC/1600
For example if fOSC = 100 kHz, fFR = 62.5 Hz
R f
OSC1 OSC2
Figure 3. Using the Internal Oscillator
OSC1 OSC2
External clock
Figure 4. Using an External Clock