Specifications

2–18 EPSON
SED1200 Series
Command Clock (Φ)
When the system MPU issues a command to the SED1200,
the timing for the execution of the command is derived
from Φ, the command clock. This would normally be the
system MPU clock.
The maximum execution time for a command is 16/Φ.
For example if Φ= 1 MHz, the maximum execution time
for a command is 16 µs.
LCD Drive Waveforms
The SED1200 has an internal low source-impedance
voltage-driver network, of the form shown in figure 5.
The switches S
Wd are closed to switch the segment data.
V DD
V LCD
R d1 R d1 R d1 R d1 R d1
R d2
V DD V L1 V L2 V L3 V L4 V LCD
R d2 R d2 R d2 R d2
S wd S wd S wd S wd S wd
Figure 5. Internal Voltage Divider