PCF8577C View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

PCF8577C

LCD direct/duplex driver with I2C-bus interface

Philips Electronics 

Philips Semiconductors

LCD direct/duplex driver with

I2C-bus interface

Product specification

PCF8577C

6.5 Direct drive mode

The PCF8577C is set to the direct drive mode by loading

the MODE control bit with logic 0. In this mode only four

bytes are required to store the data for the 32 segment

drivers. Setting the BANK bit to logic 0 selects even bytes

(BANK A), setting the BANK bit to logic 1 selects odd bytes

(BANK B).

In the direct drive mode the SBV is auto-incremented by

two after the loading of each segment byte register. This

means that auto-incremented loading of BANK A or

BANK B is possible. Either bank may be completely or

partially loaded irrespective of which bank is being

displayed. Direct drive output waveforms are shown in

Fig.4.

6.6 Duplex mode

The PCF8577C is set to the duplex mode by loading the

MODE bit with logic 1. In this mode a second backplane

signal (BP2) is needed and pin A2/BP2 is used for this;

therefore A2 and its equivalent SBV bit V5 are undefined.

The SBV auto-increments by one between loaded bytes.

All of the segment bytes are required to store data for the

32 segment drivers and the BANK bit is ignored.

Duplex mode output waveforms are shown in Fig.5.

VDD

0.5 (VDD

VSS

VSS )

VDD

0.5 (VDD

VSS

VSS )

VDD

VSS

VDD VSS

0.5 (VDD VSS )

0

0.5 (VDD VSS )

(VDD VSS )

VDD VSS

0.5 (VDD VSS )

0

0.5 (VDD VSS )

(VDD VSS )

OFF / OFF

ON / OFF

OFF / ON

ON / ON

BP1

BP2

Segment x

(Sx)

BP1 Sx

1

f LCD

BP2 Sx

MGA738

Von(rms) = 0.791 (VDD − VSS); Voff(rms) = 0.354 (VDD − VSS).

V-V----oo---fn-f--((--rr--mm----ss---))- = 2.236

Fig.5 Duplex mode display output waveforms.

1998 Jul 30

7

Share Link: