November 22, 2004

8

Philips Semiconductors

Preliminary specification

Universal LCD driver

for low multiplex rates

PCF8562

6.1

Power-on reset

At power-on the PCF8562 resets to the following starting conditions:

• Blinking is switched off

• Input and output bank selectors are reset (as defined in Table 4)

• The data pointer and the subaddress counter are cleared

• Display is disabled.

6.2

LCD bias generator

Fractional LCD biasing voltages are obtained from an internal voltage divider comprising three resistors connected in

6.3

LCD voltage selector

The LCD voltage selector co-ordinates the multiplexing of the LCD in accordance with the selected LCD drive

configuration. The operation of the voltage selector is controlled by MODE SET commands from the command decoder.

The biasing configurations that apply to the preferred modes of operation, together with the biasing characteristics as

smaller.

6.3.1

Bias is calculated by the formula

1

1a

+

-------------

1

N

----

N1

–

()

1

1a

+

-------------

⎝⎠

⎛⎞

⋅

2

+

N

------------------------------------------------------------

V

op

a

2

2a

N

+

()

–

N1

a

+

()

2

⋅

----------------------------------

V

op