EM6620WS27 datasheet(35/56 Pages) EMMICRO

35 / 56 page

EM6620

www.emmicroelectronic.com

12. LCD Driver

The EM6620 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.

Figure 25. LCD Architecture

RefLCD

LCD External

Supply

LCD Blank

Address

Bus

SEG[n]

Enable

Voff

LCD Off

Von

MUX

Output

Switches

Voltage

Multiplier

Phase

Selection

Data

Latches

Data

Bus

Phase 1 to 4

VL1

VL2

VL3

EM6620WS27 Datasheet(PDF) 35 Page - EM Microelectronic - MARIN SA