EM6520 EM Microelectronic, EM6520 Datasheet - Page 35

• Manufacturer Part Number: EM6520
• Description: MFP version of EM6620 Ultra Low Power Microcontroller 4x8 LCD Driver
• Manufacturer: EM Microelectronic

Figure 25. LCD Architecture
12 LCD Driver
The EM6520 has a built-in Liquid Crystal Display driver. A maximum of 32 segments can be displayed using
the 8 segment driver outputs (SEG[8:1) in 4:1 multiplex - 24 segments in the case of 3:1 multiplex - and the 4
back-planes (COM[4:1]).
The LCD driver has its own voltage regulator (1.05 Volt) and voltage multiplier to generate the driver bias
voltages VL1, VL2 and VL3 (VLCD). Using the metal1 mask the user can choose higher LCD reference
voltages. Please check with EM Marin the possible values and their impact on power consumption.
The special architecture of this LCD driver allows the user to specify the data and address for each individual
segment by metal mask option. It therefore adapts to every possible LCD display with a maximum of 32
independent segments. The LCD clock frequency is 256Hz. Thus the frame frequency is 256/8 Hz if 4:1
multiplex, or 256/6 if 3:1 multiplex.
Copyright  2002, EM Microelectronic-Marin SA
LCD External
LCD Blank
LCD Off
Supply
Address
Bus
Data
Bus
Data
Latches
1
2
3
4
Voltage
Multiplier
Enable
RefLCD
Phase 1 to 4
35
Phase
Selection
x3
x2
x1
www.emmicroelectronic.com
Von
EM6520
MUX
Voff
Output
Switches
SEG[n]
03/02 REV. D/449
VL3
VL1
VL2