基于PCA8538汽車102x9段玻璃覆晶(COG)LCD驅(qū)動(dòng)解決方案

NXP公司的PCA8538是汽車級(jí)102x9段玻璃覆晶（COG）LCD驅(qū)動(dòng)器，和AEC Q100 grade 2汽車應(yīng)用標(biāo)準(zhǔn)兼容，低功耗，多達(dá)114個(gè)7段數(shù)字和57個(gè)14段字符以及多達(dá)918個(gè)元素的任何圖形。工作電壓2.5V-5.5V，主要用在汽車儀表盤(pán)， 汽車娛樂(lè)系統(tǒng)，汽車無(wú)線電，工業(yè)控制和消費(fèi)電子，醫(yī)療保健，測(cè)量設(shè)備，白色家電，機(jī)器控制系統(tǒng)，和通用顯示模塊。本文介紹了PCA8538主要特性和優(yōu)勢(shì)，框圖，I2C和SPI接口的連接圖，以及評(píng)估板OM13501A 主要特性，電路圖和PCB元件分布圖。

The PCA8538 is a fully featured Chip-On-Glass （COG）1 Liquid Crystal Display （LCD） driver， designed for high-contrast Vertical Alignment （VA） LCD with multiplex rates up to 1:9. It generates the drive signals for a static or multiplexed LCD containing up to 9 backplanes， 102 segments， and up to 918 elements. The PCA8538 features an internal charge pump with internal capacitors for on-chip generation of the LCD driving voltage. To ensure an optimal and stable contrast over the full temperature range， the PCA8538 offers a programmable temperature compensation of the LCD supply voltage. The PCA8538 can be easily controlled by a microcontroller through either the two-line I2C-bus or a four-line bidirectional SPI-bus.

PCA8538主要特性和優(yōu)勢(shì)：

AEC Q100 grade 2 compliant for automotive applications

Low power consumption

Extended operating temperature range from ?40 C to +105 C

102 segments and 9 backplanes allowing to drive：

1）up to 114 7-segment numeric characters

2） up to 57 14-segment alphanumeric characters

3）any graphics of up to 918 elements

918-bit RAM for display data storage

Two sets of backplane outputs providing higher flexibility for optimal COG layout configurations

Up to 4 chips can be cascaded to drive larger displays with an internally generated or externally supplied VLCD

Selectable backplane drive configuration： static， 2， 4， 6， 8， or 9 backplane multiplexing

LCD supply voltage

1）Programmable internal charge pump for on-chip LCD voltage generation up to 5 ? VDD2

2）External LCD voltage supply possible as well

Selectable 400 kHz I2C-bus or 6.5 MHz SPI-bus interface

Selectable linear temperature compensation of VLCD

Selectable display bias configuration

Wide range for digital and analog power supply： from 2.5 V to 5.5 V

Wide LCD voltage range from 4.0 V for low threshold LCDs up to 12.0 V for high threshold twisted nematic and Vertical Alignment （VA） displays

Display memory bank switching in static， duplex， and quadruplex drive modes

Programmable frame frequency in the range of 45 Hz to 300 Hz; factory calibrated with a tolerance of ?3 Hz （at 80 Hz）

Selectable inversion scheme for LCD driving waveforms： frame or n-line inversion

Diagnostic features for status monitoring

Integrated temperature sensor with temperature readout

On chip calibration of internal oscillator frequency and VLCD

Laser marking at the back-side of the die for traceability of the lot number， wafer number， and die position on the wafer

PCA8538應(yīng)用：

Automotive

Instrument clusters

Climate control

Car entertainment

Car radio

Industrial

Consumer

Medical and health care

Measuring equipment

Machine control systems

Information boards

White goods

圖1. PCA8538框圖

圖2. 推薦的I2C接口的ITO連接圖

圖3. 推薦的SPI接口的ITO連接圖

PCA8538評(píng)估板OM13501A

This evaluation board can be used to demonstrate and evaluate the PCA8538 segment driver. This is a chip-on-glass LCD driver which can drive up to 918 segments in MUX 1:9. The board contains only the display module， some decoupling capacitors and some jumpers. The jumpers can be used for interface selection （I2C or SPI）。 A pin strip has been provided as well， which makes it easy to connect the board to any microcontroller and power supply， and start developing an application

This user manual describes the PCA8538 evaluation board. The board contains a COG display module， some decoupling capacitors for the power supply and some jumpers to configure the display driver.

The PCA8538 is a peripheral device which interfaces to almost any Liquid Crystal Display （LCD） with low multiplex rates. It generates the drive signals for any static or multiplexed LCD containing up to nine backplanes， 102 segments and up to 918 display elements. The PCA8538 features an internal charge pump with internal capacitors for on-chip generation of the LCD driving voltage. To ensure an optimal and stable contrast over the full temperature range， the PCA8538 offers a programmable temperature compensation of the LCD supply voltage. The PCA8538 can be easily controlled by a microcontroller through either the two-line I2C-bus or a four-line bidirectional SPI-bus. It is AEC Q100 grade 2 compliant for automotive applications. Please refer to the PCA8538 datasheet as well while working with this board.

This board was developed in order to provide a low cost tool for engineers， wishing to demonstrate and evaluate this LCD driver， and to get hands-on experience with writing code for it. Code written using this board can serve as an example for the final application. This enables rapid prototyping. The board can be connected to any existing application with either I2C-bus or SPI-bus interface. This application then needs to provide also the power supply， with the supply voltage ranging from 2.5 V to 5.5 V.

PCA8538評(píng)估板OM13501A 主要特性：

Provides tool for evaluating the PCA8538 LCD driver

Features a vertical alignment （VA） COG display module with integrated backlight

Jumpers for interface selection （I2C or SPI）

Jumper for selection of internal or external oscillator

Connector pins for easy connection to external microcontroller or application

圖4. PCA8538評(píng)估板OM13501A外形圖

圖5. PCA8538評(píng)估板OM13501A電路圖

圖6. PCA8538評(píng)估板OM13501A元件分布圖