xe8802 Semtech Corporation, xe8802 Datasheet - Page 157

• Manufacturer Part Number: xe8802
• Description: Data Acquisition Soc With 16+10 Bit Zoomingadc? Embedded Risc Controller And Lcd Driver
• Manufacturer: Semtech Corporation

figure shows on the left side the waveforms on the circuit pins, in the middle the segment status and on the right
the voltage on some segments (difference between the segment pin pad_lcd_io and common signals:
pad_lcd_com0, pad_lcd_com1 or pad_lcd_io[31]).
19.4.4
With 1:4 multiplexing, each pin pad_lcd_io can drive four segments of the display. In this mode, up to 120
segments of the display can be driven by the pad_lcd_io[29:0] pins. The common nodes are to be connected to the
pad_lcd_com0, pad_lcd_com1, pad_lcd_io[31] and pad_lcd_io[30]. These connections are shown in Figure 19-8.
Lots of different configurations for the voltage generation can be used. Figure 19-8 shows the connections and
external elements that are required if the display is to be driven from V3=3.6V, V2=2.4V and V1=1.2V
independently from the circuit supply voltage. Other possible configurations are given in section 19.5.4. The
recommended value for the external capacitors is 470nF.
© Semtech 2006
1:4 Multiplex scheme
VGEN
Figure 19-8: LCD with 1:4 multiplexing and on-chip 1/3 bias voltage generation.
1.2V voltage
reference
pad_lcd_io[29:0]
pad_lcd_io[30]
pad_lcd_io[31]
pad_lcd_com1
pad_lcd_com0
pad_vgen_v3
pad_vgen_v2
pad_vgen_v1
pad_vgen_va
pad_vgen_vb
pad_lcd_vr1
pad_lcd_vr2
XE8802 Sensing Machine Data Acquisition MCU
C
SEGMENTS
lcd1
COM3
COM2
COM1
COM0
C
lcd2
19-13
C
lcd3
with ZoomingADC™ and LCD driver
C
aux
LCD DISPLAY
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