PCF8562 Просмотр технического описания (PDF) - Philips Electronics

Номер в каталоге

Компоненты Описание

производитель

PCF8562

Universal LCD driver for low multiplex rates

Philips Electronics 

Philips Semiconductors

Universal LCD driver

for low multiplex rates

Preliminary specification

PCF8562

Discrimination is the ratio of Von to Voff, and is determined by the formula V-V----oo---fn-f = (-(--aa-----+–----1-1---))--2-2---+-+----((---NN------––----11----))-

Using the above formula, the discrimination for an LCD drive mode of 1 : 3 with 1⁄2bias is 3 = 1.732, and the

discrimination for an LCD drive mode of 1 : 4 with 1⁄2bias is ----3-2---1-- = 1.528.

The advantage of these LCD drive modes is a reduction of the LCD full-scale voltage VLCD as follows:

• 1 : 3 multiplex (1⁄2 bias): VLCD = 6 × Voff(rms) = 2.449 Voff(rms)

• 1 : 4 multiplex (1⁄2 bias): VLCD = (---4-----×--3-------3----) = 2.309 Voff(rms)

These compare with VLCD = 3 Voff(rms) when 1⁄3 bias is used.

Table 2 Discrimination ratios

LCD DRIVE MODE

static

1 : 2 multiplex

1 : 2 multiplex

1 : 3 multiplex

1 : 4 multiplex

NUMBER OF

LCD BIAS

BACKPLANES LEVELS CONFIGURATION

1

2

static

2

3

1⁄2

2

4

1⁄3

3

4

1⁄3

4

4

1⁄3

V-----oV--f--f-l(-c-r--md----s--)

0

0.354

0.333

0.333

0.333

V-----oV--n--l-(-c-r-m-d---s---)

1

0.791

0.745

0.638

0.577

D = V-V----oo--f-n-f-((--rr--mm----ss--))

∞

2.236

2.236

1.915

1.732

November 22, 2004

9

Share Link: