ST7571 Sitronix Technology, ST7571 Datasheet - Page 27

• Manufacturer Part Number: ST7571
• Description: 4 Gray Scale Dot Matrix LCD Controller/Driver
• Manufacturer: Sitronix Technology

ST7571
Voltage Follower Circuits
V0 is resistively divided into two voltage levels (VG, VM), and those output impedance are converted by the Voltage
Follower for increasing drive capability. Table 6 shows the relationship between VG to VM level and each duty ratio.
Table 6 The Relationship between V1 to V4 Level and Each Duty Ratio
LCD Bias
VG
VM
Remarks
1/N
2/N x V0
1/N x V0
N = 5 to 12
Booster Efficiency
The Booster Efficiency Command could be used to choose the best Booster performance. Booster Efficiency (Level1~4)
can easily set the best Booster performance with suitable current consumption. If the Booster Efficiency is set to a higher
level (level2 is higher than level1), the Boost Efficiency is better than lower level, and it just needs few more power
consumption current. When the LCD Panel loading is heavier, the performance of Booster Efficiency will be lower. We could
select higher BE level to improve the efficiency with just few more current increased.
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