WAVESHARE 4 Inch Touch LCD Module

 

OVERVIEW

4inch Touch LCD Module is a transmissive type color active matrix TFT (Thin Film Transistor) liquid crystal display (LCD) that uses amorphous silicon TFT as a switching device. This model is composed of a TFT-LCD module (TFT-LCD panel, driver IC and FPC), a back-light unit and. The resolution of 3.95″ contains 480 RGB X480 pixels and can display up to 16.7m colors.

 GENERAL INFORMATION

Items	Specification	Unit	Note
Drive element	a-Si TFT	–	–
LCM outline size	74.66 (H) x 76.54 (V)	mm
Active area	71.86 (H) x 69.51 (V)	mm	–
Number of pixels	480 (H) x 480 (V)	pixels	–
Pixel arrangement	RGB stripe	–	–
Pixel Pitch	0.1497 (H) x 0.1462 (V)	um	–
Display color	16.7m color	color	–
Viewing direction	ALL	–	–
Controller / Driver	ST7701S	–	–
Data interface	3WSPI+RGB18BIT	–
Backlight	10 White LEDs In Parallels	–
Weight	TBD	g

ABSOLUTE MAXIMUM RATING

Characteristics	Symbol	Min.	Typ	Max.	Uni t	Notes
Supply Voltage	IOVCC	-0.3	–	3.6	V
	VCI	-0.3	–	3.6	V
TFT Gate On voltage	VGH	-0.3	–	30	V
TFT Gate Off voltage	VGL	-0.3	–	30	V
Backlight Forward Current	IF	–		40	mA
Operating Temperature	TOPR	-20		+70	℃	(1), (3)
Storage Temperature	TSTG	-30		+80	℃	(2), (3)
Humidity	RH	–		90	%	Max. 60 ℃

Notes:

1. In case of below 0°C, the response time of liquid crystal (LC) becomes slower and the color of panel becomes darker than normal one. Level of retardation depends on temperature, because of the LC characteristics.
2. If product is exposed to high temperatures for extended time, there is a possibility of the polarizer film damage which could degrade the optical characteristics.
3. Permanent damage to the device may occur if maximum values are exceeded or reverse voltage is loaded. Functional operation should be restricted to the conditions described under normal operating conditions.

ELECTRICAL CHARACTERISTICS

LCM DC CHARACTERISTICS

Characteristics	Symbol	Min.	Typ.	Max.	Unit	Note
Power Supply Voltage 1	IOVCC	1.65	1.8	3.3	V
Power Supply Voltage 2	VCI	2.5	2.8	3.6	V
Power Supply Voltage 3	–	–	–	–	V
Power Supply for MTP	VPP	–	–	–	V
Current Consumption	IDD	–	TBD	–	mA	Normal mode
	IDD-SLEEP		TBD		uA	Sleep mode
Input voltage “L” Level	VIL	GND	–	0.3IOVCC	V	IOVCC=1.65~ 3.3
Input voltage “H” Level	VIH	0.7IOVCC	–	IOVCC	V
Output voltage “L” Level	VoL	IOL = +1.0mA	–	0.2IOVCC	V	IOL=1mA
Output voltage “H” Level	VoH	IOH = -1.0mA	–	IOVCC	V	IOH=-1mA

 BACK-LIGHT UNIT CHARACTERISTICS

The back-light system is an edge-lighting type with 4 white LEDs. The characteristics of the back-light are shown in the following tables.

Characteristics	Symbol	Condition	Min.	Type	Max.	Unit	Notes
Forward Voltage	Vf	IL=40mA		15	–	V	–
Forward current	IL		–	40	–	mA	–
Luminance	Lv	IL=40mA	—	400	—	cd/m2	–
LED life time	–	IL=40mA	20,000	25,000	—	Hr	Note 1

Note:

1. The “LED life time” is defined as the module brightness decrease to 50% of original brightness at IL=20mA. The LED life time could be decreased if operating IL is larger than 20mA.

OPTICAL CHARACTERISTICS

The following items are measured under stable conditions. The optical characteristics should be measured in a dark room. Measuring equipment: BM-5AS, BM-7, EZ-Contrast.

Parameter		Symbol	Condition	Min.	Typ.	Max.	Unit	Note
Contrast Ratio(Center point)		C/R	–	–	380	400	–	BM-7Note(2)
Luminance of white(Center point)		Lw	B/L on	15%	TBD	15%	cd/m2	CA-210
Luminance uniformity		UW	θ =0.Normal viewing angle    B/L OnNote(1)	80	–	–	%	BM-7Note(3)
Response Time		Tr + Tf		–	25	35	ms	BM-5ASNote(4)
Color Chromaticity (CIE 1931)	White	WX		–	0.302	–	–	CA-210 Note(5)
		WX		–	0.325	–
	Red	RX		–	0.624	–
		RY		–	0.329	–
	Green	GX		–	0.288	–
		Gy		–	0.522	–
	Blue	BX		–	0.136	–
		BY		–	0.137	–
Viewing Angle	Hor.	θT	C/R≥10	70	80	–	Deg	EZ Contrast Note(6)
		θB		70	80	–
	Ver.	θL		70	80	–
		θR		70	80	–
Optima View Direction			ALL					Note(7)

This condition will be changed by the evaluation circumstance. If product is exposed to high temperatures for extended time, there is a possibility of the polarizer film damage which could degrade the optical characteristics.

1. Notes: (1) Test Equipment Setup: After stabilizing and leaving the panel alone at a given temperature for 30min, the measurement should be executed. Measurement should be executed in a stable, windless, and dark room 30min after lighting the back-light. This should be measured in the center of screen.
2. Definition of Contrast Ratio (CR): Luminance measured when LCD on the “white” state Contrast Ratio (CR) = Luminance measured when LCD on the “black” state
3. Definition of Luminance Uniformity: Active area is divided into 9 measuring areas (Shown in below), every measuring point is placed at the center of each measuring area.
4. Luminance Uniformity= Min Luminance of white among 9-points Max Luminance of white among 9-points x100%The spot locations for luminance measurement
5. Definition of viewing angle, 0 . Refer to figure as below
6. Definition of Color Chromaticity (CIE 1931)
7. Color coordinate of white & red, green, blue at center point.
   The different Rubbing Direction will cause the different optima view direction

 MODULE OUTLINE DIMENSIONS

 

 MODULE INTERFACE DESCRIPTION

Pin No.	Symbol	Description
1	LEDA	Back-light Anode
2	LEDK	Back-light Cathode
3	LEDK	Back-light Cathode
4	GND	Power Ground
5	VCC	Power supply for I/O block. 2.8-3.3V
6	RST	Reset input pin
7	NC	NC
8	NC	NC
9	SDA	Serial data input / output bid irectional pin for SPI .
10	SCL	Serial clock input for SPI interface .
11	CS	A chip select signal
12	PCLK	Dot clock signal for RGB interface operation
13	DE	Data enable signal for RGB interface operation
14	VS	Frame synchronizing signal for RGB interface operation
15	HS	Line synchronizing signal for RGB interface operation
16-33	DB0-DB17	18bit parallel data bus for RGB Interface .
34	GND	Power Ground
35	TP-INT	Serial data output pin used for the SPI Interface.
36	TP-SDA	Power Ground
37	TP-SCL	Data enable signal for RGB interface operation
38	TP-RST	Frame synchronizing signal for RGB interface operation
39	TP-VCC	Line synchronizing signal for RGB interface operation
40	GND	Power Ground

The System interface select.

REFERENCE APPLICATION CIRCUIT

Please consult our technical department for detail information

AC CHARACTERISTICS

Serial Interface (3-lhe serial): RGB Interface character

 RELIABILITY TEST CONDITIONS

No.	Test Item	Test Condition	Notes
1	High Temperature Storage	+80°C / 240H	Inspection after 2~4h storage at room temperature, the sample shall be free from defects: Air bubble in the LCD; Seal leak; Non-display; Missing segments; Glass crack; The surface shall be free from damage. The electrical characteristics requirements shall be satisfied.
2	Low Temperature Storage	-30°C / 240H
3	High Temperature Operating	+70°C / 240H
4	Low Temperature Operating	-20°C / 240H
5	Temperature Cycle	Ta=-10°C~+25~+50°C,10Cycle,per30min
6	High Temperature /Humiditystorage	60°C ,90%RH / 240H
7	ESD test	Open Cell, Air mode, + 2 KV

Remarks:

1. The test samples should be applied to only one test item.
2. Sample size for each test item is 5~10pcs.
3. For High Temperature/Humidity storage test, pure water (resistance>10MΩ) should be used.
4. In case of malfunction defect caused by ESD damage, if it would be recovered to normal state after resetting, it would be judge as a good part.
5. Failure judgment criterion: basic specification, electrical characteristic, mechanical characteristic, optical characteristic.

PACKING SPECIFICATION

TBD

 INSPECTION CRITERION

 GENERAL PRECAUTIONS

HANDING

1. When the module is assembled, it should be attached to the system firmly. Be careful not to twist and bent the module.
2. Refrain from strong mechanical shock and / or any force to the module. In addition to damage, this may cause improper operation or damage to the module and back-light unit.
3. Note that display modules are very fragile and could be easily damaged. Do not press or scratch the surface harder than a HB pencil lead.
4. Wipe off water droplets or oil immediately. If you leave the droplets for a long time, straining and discoloration may occur.
5. If the display module surface becomes contaminated, breathe on the surface and gently wipe it with a soft dry cloth. If it is heavily contaminated, should be wiped by moisten cloth with isopropyl alcohol or ethyl alcohol solvents, DO NOT with water, ketone type materials (e.g. acetone), aromatic, toluene, ethyl acid or methyl chloride, and so on.
6. If the liquid crystal material leaks from the panel, it should be kept away from the eyes or mouth. In case of contact with hands, legs or clothes, it must be washed away thoroughly with soap.
7. Use finger-stalls with sort gloves in order to keep display clean during the incoming inspection and assembly process.
8. Protection film for polarizer on the module shall be slowly peeled off just before use so that the electrostatic charge can be minimized.
9. Do not touch directly conductive parts such as the CMOS LSI pad and the interface terminals with bare hands, therefore operations should be grounded whenever he/she comes into contact with the modules.
10. Do not exceed the absolute maximum rating value. (The supply voltage variation, input voltage variation, variation in part contents and environmental temperature, and so on), otherwise the module may be damaged.

SOLDERING

1. Use soldering irons with proper grounding and no leakage.
2. For No RoHS Product: soldering temperature is 290~350°C, soldering time is 3~5s; for RoHS Product: soldering temperature is 340~370°C, soldering time is 3~5s.
3. If soldering flux is used, be sure to remove any remaining flux after soldering (This does not apply in the case of a non-halogen type of flux).

STORAGE

1. DO NOT leave the module in high temperature and high humidity for a long times, keep the temperature from 0°C to 35°C and relative humidity of less than 60%.
2. It is highly recommended to store the module in a dark place. The Liquid crystal is deteriorated by ultraviolet, DO NOT leave it in direct sunlight and strong ultraviolet ray for many hours.

Frequently Asked Questions

• Q: What should I do if the display appears darker than normal?
  A: The level of retardation may depend on the temperature. Ensure the product is operated within the specified temperature range to maintain optimal display quality.
• Q: What are the risks of exposing the product to high temperatures for an extended period?
  A: Exposure to high temperatures can potentially damage the polarizer film, leading to degradation of optical characteristics.
• Q: How can I prevent permanent damage to the device?
  A: Avoid exceeding the maximum values specified in the manual, and ensure that reverse voltage is not applied. Operate the device under normal operating conditions to prevent permanent damage.

Documents / Resources

WAVESHARE 4 Inch Touch LCD Module [pdf] User Manual 4 Inch Touch LCD Module, 4 Inch LCD Module, Touch LCD Module, Touch Module, LCD Module, Touch LCD, Module

References

• User Manual