Waveshare HX8257-A User manual

1
4.3inch 480x272 Touch LCD (A)
User Manual
Chinese website: www.waveshare.net
English Website: www.wvshare.com
Data download: www.waveshare.net/wiki
Shenzhen Waveshare Electronics Ltd. Co.

4.3inch 480x272 Touch LCD (A) User Manual
2
Contents
1. Overview..................................................................................................................1
1.1 HX8257-A.....................................................................................................1
2. Hardware description..............................................................................................3
3. Dimensions..............................................................................................................5

1
1. Overview
Here are the main parameters of the LCD.
Module Type
TFT
Interfaces
LCD: 24-bit parallel RGA data input;
Touch panel: 4-wire resistive touch screen
Backlight
LED
Response time
(ms)
30
Contrast
500:1
Brightness(cd/m)
280
Display
area(mm)
95.04(W)×53.86(H)
Dot pitch (mm)
0.006(W)×0.198(H)
Chromatic index
16,777,216
Aspect ratio
16:9
Resolution
480 X 272 (Pixel)
Power
Dissipation
56mW
Back facet
current
20mA
Operating
temperature(℃)
-20 ~ +70
1.1 HX8257-A
HX8257-Ais aTFT LCD single chip digital driver with features below:
Support 480RGBx272 or 480RGBx240 graphics displayTFT LCD panel;
Support 8-bit serial RGB data and 24-bit parallel RGB data input;
Power supply VDD: 1.8V~3.6V;
720-channel source outputs and 544-channel gate outputs;
PWM control function to generate power for backlight.
When applying HX8257-A, a MCU with LCD controller is required, since the LCD
controller is not included in this LCD. Here is the basic sequence of HX8257-A:

4.3inch 480x272 Touch LCD (A) User Manual
2
Pin descriptions:
Symbol
Description
Vsync
Vertical sync signal, which indicates the starting to scan a
new frame. One frame refers to one picture shown in the
LCD
Hsync
Horizontal sync signal, which indicates the starting to scan a
new line
DE
Input data enable control
CLK
LCD clock
Dn7-Dn0
Parallel data
Here are the meanings of the symbols in the sequence diagram:
Symbol
Description
Reference
Unit
Min.
Typ.
Max.
fclk
LCD clock cycle
-
9
15
MHz
Horizontal signal
th
Horizontal cycle
525
525
605
CLK(1)

4.3inch 480x272 Touch LCD (A) User Manual
3
thd
Horizontal display
period
480
480
480
CLK(1)
thf
Horizontal front
porch
2
2
82
CLK(1)
thp(2)
Horizontal pulse
width
2
41
41
CLK(1)
thb(2)
Horizontal back
porch
2
2
41
CLK(1)
Vertical signal
tv
Vertical cycle
285
286
399
H(1)
tvd
Vertical display
period
272
272
272
H (1)
tvf
Vertical front porch
1
2
227
H (1)
tvp (2)
Vertical pulse width
1
10
11
H (1)
tvb (2)
Vertical back porch
1
2
11
H (1)
Remarks:
(1) Unit: CLK=1/fCLK, it is the duration for scanning a pixel; H=th, it is the duration for
scanning a line;
(2) It is necessary to keep tvp+tvb=12 and thp+thb=43 in sync mode. DE mode is
unnecessary to keep it.
From the figure above, we can learn that:
The total time for scanning a line is: th = thp + thb + thd + thf; in the period of thd, when a
clock plus comes, a pixel data will be transmitted via the parallel data interface. And there
are 480 pixels each line for this LCD, so thd=480;
The duration for scanning a frame is: tv = tvp + tvb + tvd + tvf；Hsync can be regarded as
the clock of vertical signals. A clock cycle of Hsync refers to the duration for LCD
displaying a line. When a falling edge comes in Hsync, a new line will be displayed in the
LCD. However, the actual data transmission only occurs in the period of tvd. And the LCD
will display the new line in this case.There are 272 lines for this LCD, so tvd = 272.
Other parameters can be modified as required, according to the specificationslisted in the
tables above.
2. Hardware description
Pin No.
Symbol
Descriptions
I/O
Functions
1
5V
5V power
supply
I
Supply 5V power voltage
2
3
B0
Data line
I
Blue pallet data line
4
B1
5
B2

4.3inch 480x272 Touch LCD (A) User Manual
4
6
B3
7
B4
8
B5
9
B6
10
B7
11
GND
Ground
I
GND
12
G0
Data line
I
Green pallet data line
13
G1
14
G2
15
G3
16
G4
17
G5
18
G6
19
G7
20
GND
Ground
I
GND
21
R0
Data line
I
Red pallet data line
22
R1
23
R2
24
R3
25
R4
26
R5
27
R6
28
R7
29
GND
Ground
I
GND
30
BL_EN
Backlight
enable
I
1: Backlight ON
0: Backlight OFF
31
PWM
Backlight
brightness
control
I
Signal line for PWM control
backlight
32
NC
33
DE
Input data
enable control
I
DE=0: SYNC mode
DE=1: DE mode
34
VSYNC
Horizontal
synchronizatio
n
I
Horizontal sync signal input
35
HSYNC
Vertical
synchronizatio
n
I
Vertical sync signal input
36
DCLK
LCD clock
I
LCD clock signal source
37
Y+
Touch panel
Y+
O
Resistive touch panel Y+
analog output
38
Y-
Touch panel Y-
O
Resistive touch panel Y-
analog output

4.3inch 480x272 Touch LCD (A) User Manual
5
39
X+
Touch panel
X+
O
Resistive touch panel X+
analog output
40
X-
Touch panel X-
O
Resistive touch panel X- analog
output
4.3inch 480x272 Touch LCD (A) and 4.3inch 480x272 Touch LCD (B) share a same
design of PCB. The differences between them are the parts on the boards and the way to
lead out the pins. For 4.3inch 480x272 Touch LCD (A), its pins are led out with the FFC
cable, including the pins Y-,Y+,X- and X+, and no touch chip is integrated on the board.
For 4.3inch 480x272Touch LCD (B), its pins areled out via thepin headers, and thereis a
touch chip XPT2046 integrated on the board.
3. Dimensions