TOPWAY LMT028FNHFWA LCD Module User Manual

: June 1, 2024
: Topway

Table of Contents

TOPWAY LMT028FNHFWA LCD Module
Basic Specifications
Terminal Functions
Absolute Maximum Ratings
Electrical Characteristics
AC Characteristics
Functions
Optical Characteristics
LCD Module Design and Handling Precautions
Dimension
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TOPWAY LMT028FNHFWA LCD Module

Rev.	Descriptions	Edit	Release Date
0.1	Preliminary New release	Caiwei	2023-11-14

0.2

| Update Operating Temperature and Storage Temperature of 1.and 2.、 Luminance of 5.Optical Characteristics and Outline 、Change Vf of

3.2 note2 and TFT Driver IC to ST7789VI

|

Caiwei

|

2024-03-07

| | |
| | |
| | |

Basic Specifications

Screen Size(Diagonal) : 2.8”
Active Area: 43.2×57.6 (mm)
Number of dots: 240 (RGB) x 320
Pixel Pitch： 0.18×0.18 mm
Color Depth: 65k/262K colors
Display Technology: a-Si TFT active matrix
Display Mode: Normally black, Transmissive
Display Interface: MCU_8/16bit/4-SPI
Viewing Direction: Full
Surface Treatment: HC
Operating Temperature: -30 ~ +85°C
Storage Temperature: -30 ~ +85°C

Note:

Color tone may slightly change by temperature and driving condition

Block Diagram

Terminal Functions

Absolute Maximum Ratings

Items	Symbol	Min.	Max.	Unit	Condition
Supply Voltage	VCC	-0.3	+4.6	V	GND = 0V
Logic Voltage	IOVCC	-0.3	+4.6	V	GND = 0V
Operating Temperature	TOP	-30	+85	°C	No Condensation
Storage Temperature	TST	-30	+85	°C	No Condensation

Cautions:

Any Stresses exceeding the Absolute Maximum Ratings may cause substantial damage to the device. Functional operation 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

Electrical Characteristics

DC Characteristics

VCC=3.3V, GND=0V, TOP=25 C

Items| Symbol| MIN.| TYP.| MAX.| Unit| Application Pin
---|---|---|---|---|---|---
Supply voltage for logic| VCC| 3.2| 3.3| 3.4| V| VCC
Logic Supply voltage| IOVCC| 3.2| 3.3| 3.4| V| IOVCC
Input High Voltage| VIH| 0.7

IOVCC

| –| IOVCC| V| SDA,/RD,/WR,D/C,

/CS,/SCL,IM123,IM0,

/RESET,DB0~DB15

Input Low Voltage| VIL| –| –| 0.3

IOVCC

| V
Output High Voltage| VOH| 0.8

IOVCC

| –| IOVCC| V|

DB0~DB15,SDO, FMARK

Output Low Voltage| VOL| GND| –| 0.2

IOVCC

| V
Operating Current| IVCC| –| 8.6| 21.5| mA| VCC

LED Backlight Circuit Characteristics

TOP=25 C

Items| Symbol| MIN.| TYP.| MAX.| Unit| Remark
---|---|---|---|---|---|---
Forward Voltage| VF| 3.0| 3.2| 3.4| V| For each LED
Forward Current| If| –| 20| –| mA| For each LED
LED Life Time| –| –| 30,000| –| Hrs| For each LED

Note1: LED CIRCUIT DIAGRAM

Note 2: LED: VF =3.2V, IF =20mA(TYP)
Note 3: IF is defined for one LED.
Optical performance should be evaluated at Ta=25℃ only. If LED is driven by high current, high ambient temperature & humidity condition. The life time of LED will be reduced. Operating life means brightness goes down to 50% initial brightness. Typical operating life time is estimated data.
Note 4: Under LCM operating, the stable forward current should be inputted. And forward voltage is for reference only.
Note 5: The LED driving condition is defined for each LED module.

AC Characteristics

8080 Mode System Bus Timing

Note:

Input signal rise/fall time should be less than 15ns .
All timing is using 20% and 80% of VDD as the reference.
Please refer to ST7789VI datasheet for details

4 line SPI Timing

Note: The rising time and falling time (Tr, Tf) of input signal are specified at 15 ns or less. Logic high and low levels are specified as 30% and 70% of VDDI for Input signals.

Reset Timing

Functions

Display Commands

Notes:

There will be no abnormal visible effects on the display when S/W or H/W Reset are applied.
Please refer to ST7789VI datasheet for details.

Power off the LCD Module

It recommends that enter Sleep Mode before power off the LCD module.

Refreshing The LCD Module

It recommends that the operating modes and display contents be refreshed periodically to prevent the effect of unexpected noise.

Optical Characteristics

VCC=3.3V, GND=0V, TOP=25 C

ILEDA= 20mA and the ambient temperature is 25℃.
The test systems refer to Note 1 and Note 2.

Note 1: Definition of optical measurement system.

The optical characteristics should be measured in dark room. After 5 Minutes operation, the optical properties are measured at the center point of the LCD screen. All input terminals LCD panel must be ground when measuring the center area of the panel.

Measuring surroundings: Dark room
Measuring temperature: Ta=25℃.

Note 2: Definition of viewing angle range and measurement system.

The definition of viewing angle

Note 3: Definition of contrast ratio

The definition of contrast ratio (Test LCM using SR-3A (1°)):

(Contrast Ratio is measured in optimum common electrode voltage)

Note 4: Definition of Response time

Definition of Response time.

The response time is defined as the LCD optical switching time interval between “White” state and “Black” state. Rise time (TON ) is the time between photo detector output intensity changed from 90% to 10%. And fall time (TOFF ) is the time between photo detector output intensity changed from 10% to 90%.

Note 5: Definition of color chromaticity (CIE1931)

Definition of Color of CIE1931 Coordinate and NTSC Ratio.

Color gamut

Note 6: Definition of Luminance Uniformity

Active area is divided into 9 measuring areas (Refer Fig. 2). Every measuring point is placed at the center of each measuring area.

Luminance Uniformity (U) = Lmin/ Lmax

L——-Active area length W—– Active area width
Lmax: The measured Maximum luminance of all measurement position.
Lmin: The measured Minimum luminance of all measurement position.

Note 7: Definition of Luminance:

Measured the luminance of white state at center point

LCD Module Design and Handling Precautions

Please ensure V0, VCOM is adjustable, to enable LCD module get the best contrast ratio under different temperatures, view angles and positions.
Normally display quality should be judged under the best contrast ratio within viewable area. Unexpected display pattern may come out under abnormal contrast ratio.
Never operate the LCD module exceed the absolute maximum ratings.
Never apply signal to the LCD module without power supply.
Keep signal line as short as possible to reduce external noise interference.
IC chip (e.g. TAB or COG) is sensitive to light. Strong light might cause malfunction. Light sealing structure casing is recommended.
Make sure there is enough space (with cushion) between case and LCD panel, to prevent external force passed on to the panel; otherwise that may cause damage to the LCD and degrade its display result.
Avoid showing a display pattern on the screen for a long time (continuous ON segment).
LCD module reliability may be reduced by temperature shock.
When storing and operating LCD module, avoids exposure to direct sunlight, high humidity, high or low temperature. They may damage or degrade the LCD module.
Never leave LCD module in extreme condition (max./min storage/operate temperature) for more than 48hr.
Recommend LCD module storage conditions is 0 C~40 C <80%RH.
LCD module should be stored in the room without acid, alkali and harmful gas.
Avoid dropping & violent shocking during transportation, and no excessive pressure press, moisture and sunlight.
LCD module can be easily damaged by static electricity. Please maintain an optimum anti-static working environment to protect the LCD module. (eg. ground the soldering irons properly)
Be sure to ground the body when handling LCD module.
Only hold LCD module by its sides. Never hold LCD module by applying force on the heat seal or TAB.
When soldering, control the temperature and duration avoid damaging the backlight guide or diffuser which might degrade the display result such as uneven display.
Never let LCD module contact with corrosive liquids, which might cause damage to the backlight guide or the electric circuit of LCD module.
Only clean LCD with a soft dry cloth, Isopropyl Alcohol or Ethyl Alcohol. Other solvents (e.g. water) may damage the LCD.
Never add force to components of LCD module. It may cause invisible damage or degrade the module’s reliability.
When mounting LCD module, please make sure it is free from twisting, warping and bending.
Do not add excessive force on surface of LCD, which may cause the display color change abnormally.
LCD panel is made with glass. Any mechanical shock (e.g. dropping from high place) will damage the LCD module.
Protective film is attached on LCD screen. Be careful when peeling off this protective film, since static electricity may be generated.
Polarizer on LCD gets scratched easily. If possible, do not remove LCD protective film until the last step of installation.
When peeling off protective film from LCD, static charge may cause abnormal display pattern. The symptom is normal, and it will turn back to normal in a short while.
LCD panel has sharp edges, please handle with care.
Never attempt to disassemble or rework LCD module.
If display panel is damaged and liquid crystal substance leaks out, be sure not to get any in your mouth, if the substance comes into contact with your skin or clothes promptly wash it off using soap and water.

Warranty

This product has been manufactured to our company’s specifications as a part for use in your company’s general electronic products. It is guaranteed to perform according to delivery specifications. For any other use apart from general electronic equipment, we cannot take responsibility if the product is used in medical devices, nuclear power control equipment, aerospace equipment, fire and security systems, or any other applications in which there is a direct risk to human life and where extremely high levels of reliability are required. If the product is to be used in any of the above applications, we will need to enter into a separate product liability agreement.

We cannot accept responsibility for any defect, which may arise form additional manufacturing of the product (including disassembly and reassembly), after product delivery.
We cannot accept responsibility for any defect, which may arise after the application of strong external force to the product.
We cannot accept responsibility for any defect, which may arise due to the application of static electricity after the product has passed our company’s acceptance inspection procedures.
When the product is in CCFL models, CCFL service life and brightness will vary according to the performance of the inverter used, leaks, etc. We cannot accept responsibility for product performance, reliability, or defect, which may arise.
We cannot accept responsibility for intellectual property of a third part, which may arise through the application of our product to our assembly with exception to those issues relating directly to the structure or method of manufacturing of our product.