PCF85134 datasheet(6/40 Pages) NXP

6 / 40 page

PCF85134_1

Product data sheet

Rev. 01 — 17 December 2009

6 of 40

NXP Semiconductors

PCF85134

Universal LCD driver for low multiplex rates

Functional description

The PCF85134 is a versatile peripheral device designed to interface any microprocessor

or microcontroller to a wide variety of LCDs. It can directly drive any static or multiplexed

LCD containing up to four backplanes and up to 60 segments.

The display conﬁgurations possible with the PCF85134 depend on the number of active

backplane outputs required. A selection of display conﬁgurations is shown in Table 4. All

of these conﬁgurations can be implemented in the typical system shown in Figure 3.

The host microprocessor or microcontroller maintains the 2-line I2C-bus communication

channel with the PCF85134.

Biasing voltages for the multiplexed LCD waveforms are generated internally, removing

the need for an external bias generator. The internal oscillator is selected by connecting

pin OSC to VSS. The only other connections required to complete the system are the

power supplies (pins VDD, VSS and VLCD) and the LCD panel selected for the application.

7.1 Power-On Reset (POR)

At power-on, the PCF85134 resets to the following default starting conditions:

• All backplane outputs are set to VLCD

• All segment outputs are set to VLCD

• The selected drive mode is: 1:4 multiplex with 1

⁄

3 bias

• Blinking is switched off

• Input and output bank selectors are reset

Table 4.

Selection of display conﬁgurations

Number of

7-segment alphanumeric

14-segment alphanumeric

Dot matrix

Backplanes

Elements

Digits

Indicator symbols

Characters

Indicator symbols

240

240 (4

× 60)

180

180 (3

× 60)

120

120 (2

× 60)

60 (1

× 60)

Fig 3.

Typical system conﬁguration

HOST

MICRO-

PROCESSOR/

MICRO-

CONTROLLER

2Cb

SDA

SCL

OSC

60 segment drives

4 backplanes

LCD PANEL

(up to 240

elements)

PCF85134

SA0

VDD

VSS

VDD

VLCD

013aaa206

≤

PCF85134 датащи(PDF) 6 Page - NXP Semiconductors

PCF85134 датащи(HTML) 6 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

датащи скачать

ссылки URL