AN1447 datasheet(3/26 Pages) STMICROELECTRONICS

부품명	AN1447

상세설명	SOFTWARE DRIVER FOR 4-MULTIPLEXED LCD WITH A STANDARD ST62

PDF	26 Pages

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제조업체	STMICROELECTRONICS [STMicroelectronics]

홈페이지	http://www.st.com

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4-MULTIPLEXED LCD WITH A STANDARD ST62

Figure 2. Connections inside a direct drive LCD

All these pins are connected to MCU I/O pins operating in output mode, either at logic level 0

or at logic level 1.

The backplane is driven with a signal

COM controlled between 0 and VDD with a duty cycle of

50%.

When selecting a segment ON, a signal with opposite polarity to

COM is sent to the corre-

sponding segment electrode pin. When the non-inverted signal

COM is sent to the segment

electrode pin, the segment is OFF.

Figure 3. LCD signals for non-multiplexed drive

Note: on Figure 3,

S signal is the “segment electrode voltage” and S∆ the “segment voltage”.

COM

backplane

segment

electrodes

…

COM

S∆ = COM - S

Vdd

-Vdd

(

S∆)RMS = 0 ⇒ segment OFF

(

S∆)RMS = Vdd ⇒ segment ON

S∆

AN1447 데이터시트(PDF) 3 Page - STMicroelectronics