LMT028DHHFWL-NNA
LCD Module User Manual
Prepared by:
Checked by:
Approved by:
Wei
Date: 2019-07-05
Date:
Date:
Rev. Descriptions
Release Date
0.1
Preliminary New release
2018-03-30
0.2
Add Touch panel Design Precautions
2019-03-30
0.3
Update Outline Dimension
2019-07-05
URL: www.topwaydisplay.com
Document Name: LMT028DHHFWL-NNA-Manual-Rev0.3
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LCD Module User Manual
LMT028DHHFWL-NNA
Table of Content
1. Basic Specifications .............................................................................................................. 3
1.1 Block Diagram ............................................................................................................................................................... 3
1.2 Terminal Functions ........................................................................................................................................................ 4
1.3 Touch Panel Terminal Functions ................................................................................................................................... 4
2. Absolute Maximum Ratings .................................................................................................. 5
3. Electrical Characteristics ...................................................................................................... 5
3.1 DC Characteristics ........................................................................................................................................................ 5
3.2 LED Backlight Circuit Characteristics ............................................................................................................................ 5
3.3 AC Characteristics ......................................................................................................................................................... 6
3.4 Reset Timing ................................................................................................................................................................. 7
4. Functions ............................................................................................................................... 8
4.1 Display Commands ....................................................................................................................................................... 8
4.2 Power off the LCD Module .......................................................................................................................................... 13
4.3 Refreshing The LCD Module ....................................................................................................................................... 13
5. Optical Characteristics ........................................................................................................ 13
6. Design and Handling Precaution ........................................................................................ 15
7. Touch panel Design Precautions ........................................................................................ 15
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Document Name: LMT028DHHFWL-NNA-Manual-Rev0.3
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LCD Module User Manual
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1. Basic Specifications
Screen Size(Diagonal) :
2.8”
Color Depth:
65k colors
Number of dots :
240 (RGB) x 320
Active Area :
43.2x57.6 mm
Dot Pitch :
0.18x0.18 mm
Display Technology :
a-Si TFT active matrix
Display Mode :
Transmissive with normally white
Pixel Configuration :
RGB Stripe
Viewing Direction :
12H(gray scale inverse)
Backlight Type:
LEDs
Outline Dimension :
48.4 x 69.2 x 4.3 mm (exclude FPC)
(see dwg for details)
Operating Temperature :
-20 ~ +70°C
Storage Temperature :
-30 ~ +80°C
1.1 Block Diagram
XL,XR,YU,YD
Touch Panel
LEDA
LEDK1, LEDK2, LEDK3, LEDK4
Backlight Circuit
240(RGB) x 320 pixels
TFT Panel
DB0~DB15
ST7789VI or equivalent
VDD, IOVDD,VCI, VSS
IM0, FMARK, /RES, /RD, /WR, D/C, /CS
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1.2 Terminal Functions
Pin Pin
Descriptions
No. Name
I/O
16bit
8bit
1
VSS
P
Power Ground
2
DB0
3
DB1
4
DB2
I/O Data Bus
Connect VSS
5
DB3
6
VSS
P
Power Ground
7
IOVDD
P
Interface power supply
8
/CS
I
Chip select signal: active Low
9
D/C
I
Data/Command select signal 0:Command,1-Data
10
/WR
I
Write signal: active Low
11
/RD
I
Read signal: active Low
12
IM0
I
0:16bit I/F
1:8bit I/F
13
14
15
NC
-
No connect
16
17
LEDA
P
LED Anode
18
LEDK1
P
LED Cathode1
19
LEDK2
P
LED Cathode2
20
LEDK3
P
LED Cathode3
21
LEDK4
P
LED Cathode4
22
FMARK
O
Frame mark Output signal(could leave open)
23
DB4
I/O Data Bus
Connect VSS
24
DB8
DB0
:
:
I/O Data Bus
:
31
DB15
DB7
32
/RES
I
Reset signal: active Low
33
VCI
P
Analog and Logic power supply
34
VDD
P
Analog and Logic power supply
35
VSS
P
Power Ground
36
DB5
37
DB6
I/O Data Bus
Connect VSS
38
DB7
39
VSS
P
Power Ground
1.3 Touch Panel Terminal Functions
Pin No Pin Name
I/O
Descriptions
1
XL
Passive Left Side sense terminal
2
YD
Passive Down Side sense terminal
3
XR
Passive Right Side sense terminal
4
YU
Passive Up Side sense terminal
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2. Absolute Maximum Ratings
Items
Symbol
Min.
Max.
Unit Condition
Supply Voltage
VDD
-0.3
+4.6
V
VSS = 0V
Logic Voltage
IOVDD
-0.3
+4.6
V
VSS = 0V
Operating Temperature
T OP
-20
+70
 C
No Condensation
Storage Temperature
T ST
-30
+80
 C
No Condensation
Cautions:
Any Stresses exceeding the Absolute Maximum Ratings may cause substantial damage to the device. Functional oper-
ation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to
extreme conditions may affect device reliability.
3. Electrical Characteristics
3.1 DC Characteristics
VDD=3.3V, VSS=0V, T OP =25  C
Items
Symbol
MIN.
TYP.
MAX.
Unit Condition /
Application Pin
Operating Voltage
IOVDD
1.65
1.8
3.6
V
IOVDD
VDD
3.0
3.3
3.6
V
VDD,VCI
Input High Voltage
V IH
0.7* IOVDD
-
IOVDD
V
DB0~DB15,/CS,
Input Low Voltage
V IL
0
-
0.3* IOVDD
V
/WR,D/C,/RD,/RES
Operating Current
I DD
-
6.0
15.0
mA VDD
3.2 LED Backlight Circuit Characteristics
LEDK(1~4)=0V, I LEDA =80mA, T OP =25  C
Items
Symbol
MIN.
TYP.
MAX.
Unit Application Pin
Forward Voltage
LEDA
2.8
3.0
3.2
V
LEDA
Forward Current
I LEDA
-
80
-
mA LEDA
Cautions:
Exceeding the recommended driving current could cause substantial damage to the backlight and shorten its lifetime.
LEDA
LEDK1 LEDK2 LEDK3 LEDK4
No. of LEDs = 4pcs
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3.3 AC Characteristics
8080 Mode System Bus Timing
VDD=3.3V, VSS=0V, T OP =25  C
Signal
Symbo
Spec.
l
Parameter
Min.
Max.
Unit
Description
Address setup time
5
-
D/C
T AST
ns
-
T AHT
Address hole time(Write/Read)
13
-
T CHW
Chip select “H” pulse width
5
-
T CS
Chip select setup time(Write)
20
-
Chip select setup time(Read ID)
60
-
/CS
T RCS
ns
-
T RCSFM Chip select setup time(Read FM)
460
T CSF
Chip select wait time(Write/Read)
13
T CSH
Chip select hold time
13
T WC
Write cycle
86
-
/WR
T WRH Control pulse “H” duration
20
-
ns
-
T WRL Control pulse “L” duration
20
-
T DST
Data setup time
13
-
For maximum
T DHT
Data hold time
13
-
CL=30pF
DB[15:0]
T RAT
Read access time(ID)
-
52
ns
For minimum
T RATFM Read access time(FM)
-
442
CL=8pF
T ODH
Ouput disable time
14
104
T RC
Read cycle(ID)
208
/RD(ID)
T RDH
Control pulse “H” duration(ID)
120
When read ID data
T RDL
Control pulse “H” duration(ID)
60
ns
T RCFM Read cycle(FM)
585
/RD(FM)
When read from
T RDHFM Control pulse “H” duration(FM)
120
frame memory
T RDLFM Control pulse “H” duration(FM)
460
Note:
*1. Input signal rise/fall time should be less than 15ns .
*2. All timing is using 20% and 80% of VDD as the reference.
*3. Please refer to ST7789VI datasheet for details
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3.4 Reset Timing
VDD=3.3V, VSS=0V, T OP =25  C
Item
Symbol
MIN.
TYP.
MAX.
Unit
Reset LOW pulse width
t RW
10
-
-
us
Reset time
T RT
-
-
170
ms
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4. Functions
4.1 Display Commands
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LCD Module User Manual
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Notes:
1. There will be no abnormal visible effects on the display when S/W or H/W Reset are applied.
2.
Please refer to ST7789VI datasheet for details
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4.2 Power off the LCD Module
It recommends that enter Sleep Mode before power off the LCD module.
4.3 Refreshing The LCD Module
It recommends that the operating modes and display contents be refreshed periodically to prevent
the effect of unexpected noise.
5. Optical Characteristics
VDD=3.3V, VSS=0V, T OP =25  C
Item
Symbol
Condition
MIN.
TYP.
MAX.
UNIT
Note.
Φ=90 o
50
60
-
Viewing angle
Φ=270 o
40
50
-
(CR ≥ 10)
degree
Note 1,6
Φ=180 o
50
60
-
Φ=0 o
50
60
-
Φ=0 o
Contrast ratio
CR
θ=0 o
300
500
-
-
Note 3
Φ=0 o
Response Time
T on + T off
θ=0 o
-
30
50
msec
Note 4
X
0.55
0.60
0.65
Red
Y
0.30
0.35
0.40
X
Backlight
0.27
0.32
0.37
Green
Y
is on
0.56
0.61
0.66
Chromaticlty
Φ=0 o
Note 1,5
X
0.09
0.14
0.19
Blue
θ=0 o
Y
0.05
0.09
0.15
X
0.26
0.29
0.32
White
Y
0.28
0.31
0.34
NTSC Ratio
S
45
65
-
%
Luminance
L
Φ=0 o
160
200
-
cd/m 2
Note 1,6
θ=0 o
Luminance uniformity
U
80
-
-
%
Note 1,6
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Note 1:
Note 2:
The data are measured after LEDs are turned on for 5 minutes.
The definition of viewing angle:
LCM displays full white. The brightness is the average value of 9 Refer to the graph below marked by θ and Ф
measured spots. Measurement equipment PR-705
Measuring condition:
- Measuring surroundings: Dark room
- Measuring temperature: Ta=25 ℃ .
- Adjust operating voltage to get optimum contrast at
the center of the display.
Note 3:
The definition of contrast ratio (Test LCM using PR-705):
Note 4:
Contrast
Luminance When LCD is at “White” state
Definition of Response time. (Test LCD using DMS501):
Ratio(CR)
=
Luminance When LCD is at “Black” state
The output signals of photo detector are measured
(Contrast Ratio is measured in optimum common electrode
when the input signals are changed from
voltage)
“black” to “white”(falling time)
and from “white” to “black”(rising time), respectively.
The response time is defined as
the time interval between the 10% and 90% of amplitudes.Refer to
figure as below.
Note 5:
Note 6:
Definition of Color of CIE1931 Coordinate and NTSC Ratio.
The luminance uniformity is calculated by using following formula.
△ Bp = Bp (Min.) / Bp (Max.)×100 (%)
Color gamut:
Bp (Max.) = Maximum brightness in 9 measured spots
Area of RGB triangle
S=
X100%
Bp (Min.) = Minimum brightness in 9 measured spots .
Area of NTSC triangle
Note 7:
Measured the luminance of white state at center point
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6. Design and Handling Precaution
Please refer to "LCD-Module-Design-Handling-Precaution.pdf".
7. Touch panel Design Precautions
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