NXP Semiconductors UM10726 User manual

UM10726
User manual for the PCA8538 evaluation board OM13501A
Rev. 2 — 18 July 2013
User manual
Document information
Info
Content
Keywords
LCD driver, segment driver, COG, Chip-On-Glass, PCA8538, Vertical
Alignment (VA)
Abstract
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.

NXP Semiconductors
UM10726
User manual PCA8538 evaluation board
UM10726
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
User manual
Rev. 2 — 18 July 2013
2 of 10
Contact information
For more information, please visit:
http://www.nxp.com
For sales office addresses, please send an email to: salesaddr[email protected]
Revision history
Rev
Date
Description
2
20130718
2nd revision
Type number of board corrected, from OM13502 to OM13501A
1
20130702
First version

NXP Semiconductors
UM10726
User manual PCA8538 evaluation board
UM10726
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
User manual
Rev. 2 — 18 July 2013
3 of 10
1. Introduction
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.
Features:
•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

NXP Semiconductors
UM10726
User manual PCA8538 evaluation board
UM10726
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
User manual
Rev. 2 — 18 July 2013
4 of 10
2. Board description and layout
Fig 1 shows a picture of the board.
Fig 1. PCA8538 evaluation board
For best optical performance, remove the protective foil from the display.
The jumpers are visible on the left, the pins for connecting the module are at the bottom
of the board.
3. Board schematic and layout
The schematic of the board is given in Fig 2. The board contains the display module (on
the left) with integrated backlight module, indicated on the right as “LED Backlight”. In
addition it contains decoupling capacitors for VDD (C1) and for VLCD (C2). The network
R1/C3 pulls down the RESET pin when the module is powered up, thus generating a
reset (active LOW). Pin 1 can also be connected to a GPIO of a microcontroller, allowing
the microcontroller to generate a reset.

NXP Semiconductors
UM10726
User manual PCA8538 evaluation board
UM10726
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
User manual
Rev. 2 — 18 July 2013
5 of 10
VLCD can either be generated by the internal charge pump or it can be supplied with a
second supply voltage (pin 13 of connector P1). In that case the internal charge pump
must be disabled. Jumper JP6 should be removed when using an external VLCD supply
voltage.
Fig 2. PCA8538 evaluation board schematic
3.1 Jumper settings
The board contains seven jumpers. Five are required for the interface selection. There is
one jumper for oscillator selection and one jumper related to VLCD.
Table 1. Interface selection jumpers
Jumper
SPI-bus
I2C-bus
JP1, IFS
V
SS
(GND)
V
DD
JP2, nCE
active LOW, chip enable
unused, connect to V
DD
JP4, SA0
V
SS
V
SS
for logic 0, V
DD
for logic 1
JP5, SA1
V
SS
V
SS
for logic 0, V
DD
for logic 1
JP7, SDAOUT
unused, connect to V
SS
(Place)
serial data output (Remove jumper)
The other jumpers are listed in Table 2.