ST7575 datasheet(49/51 Pages) SITRONIX

49 / 51 page

ST7575

Ver 1.3

49/51

2007/09/12

Selection of Application Voltage

Power Range Summary

Positive Booster: (VDD2 x PCn x BE) ≥ V0 or (VDD2 x PCn x BE) ≥ Vop;

Negative Booster: [–VDD2 x (PCn – 1) x BE] ≤ XV0 or [VDD2 x (PCn – 1) x BE] ≥ (Vop – VG),

where VG = Vop x 2 / N;

Vop requirement: [VDD2 x (PCn – 1) x BE] ≥ [Vop x (N – 2) / N] or [Vop ≤ VDD2 x (PCn – 1) x BE x N / (N – 2)].

PCn is the booster stage and BE is the booster efficiency. Referential values are listed below: (assume VDD2=2.4V)

Module Size ≤ 1.4”: BE=80% (min);

Module Size = 1.4”~1.8”: BE=76% (min).

Actual BE should be determined by module loading and ITO resistance value.

1.24 ≤ VG < VDD2. Recommend VG is: VDD2-VG around 0.5~0.8V.

VM=VG/2 and 0.62V ≤ VM < VDD2.

The worse condition should be considered:

Low temperature effect and display on with snow pattern on panel (max: 1.8”).

Referential LCD Module Setting

VDD1=VDD2=2.8V, Panel Size=1.4”

Duty

Booster

Vop

Bias

1/66

5X,

CP=H

8.49V ~ 9V,

PRS=1

1/9,

BS[2:0]=0,1,1

Note: It is recommended to reserve some range for user adjustment and temperature effect.

ST7575 Datasheet(PDF) 49 Page - Sitronix Technology Co., Ltd.