LS0395I18-R-V1 (ST7701P): 3.95-inch TFT LCD Module, 480×480, RGB/SPI Interface, 16.7M Colors, Transmissive IPS
Product Subtitle / Keywords
3.95 Inch Display, 480(RGB)×480 Resolution, Transmissive a-Si TFT-LCD Module, COG+FPC+B/L Module Type, RGB 18-bit / SPI Interface, 16.7M Colors (24-bit), Main LCD Driver: ST7701P, IPS Display Mode (ALL View), Module Size: 74.66 × 76.54 × 2.11 mm, Active Area: 71.86 × 70.18 mm, Operating Temp: -20°C ~ +70°C, Storage Temp: -30°C ~ +80°C, Backlight: 10 Chip-White LED (Parallel), Vf=3.0V (Typ.) per LED, If=200mA (Total), Module Luminance: 350 cd/m², Viewing Angle: IPS (ALL, 80° Typ.), Contrast Ratio: 800:1 (Typ.), Response Time: 30ms (Typ.), RoHS Compliant, GB/T 2828-2003 Inspection, Product Revision 1.0
1. Executive Summary And Product Positioning
The LS0395I18-R-V1 is a 3.95-inch diagonal transmissive type a-Si TFT-LCD (amorphous silicon thin film transistor liquid crystal display) module, manufactured by Lesson (Wanan) Smart Display Technology Co., Ltd. This comprehensive module is a complete, ready-to-use visual interface solution, integrating a TFT-LCD panel, a driver circuit, and a backlight unit (B/L) into a compact and robust package. The product specification (Revision 1.0) serves as the definitive technical document for this module.
This module is characterized by its unique square display in a compact 3.95-inch form factor. It features a resolution of 480(RGB)×480 pixels and is capable of displaying up to 16.7M colors, which corresponds to 24-bit color depth (8-bit per primary color Red, Green, Blue). This ensures smooth color gradients and detailed imagery suitable for advanced graphical user interfaces. The square aspect ratio is ideal for applications like smart home displays, IoT control panels, and automotive instrument clusters.
The unequivocal recommendation for engineers is to strictly adhere to the absolute maximum ratings, electrical specifications, and interface timing described herein to ensure reliable performance and compatibility within the intended application. Failure to operate within these limits can lead to permanent damage, degraded optical performance, or reduced product lifespan. The manufacturer has provided key recommendations for mechanical integration, including VA area clearance and TP placement.
2. Detailed Product Overview And Architecture
The LS0395I18-R-V1 is engineered for devices that demand a clear, vibrant square display in a compact package, such as smart home control panels, IoT edge terminals, and automotive instrument clusters. Its architecture is built around several key technologies and design choices:
- Core Technology: Transmissive type a-Si TFT-LCD with IPS (In-Plane Switching) display mode. This technology offers superior color reproduction and wide viewing angles (specified as "ALL" direction). As a transmissive display, it requires a backlight to be visible. The display type is Transmissive, IPS.
- Module Type: COG (Chip-On-Glass) + FPC (Flexible Printed Circuit) + B/L (Backlight). The driver IC (ST7701P) is directly mounted onto the LCD glass (COG), minimizing size and interconnect complexity. The FPC provides a flexible connection to the host system. The module outline dimensions are 74.66(H) × 76.54(V) × 2.11(D) mm.
- Display Format: Graphic 480(RGB)×480 Dot-matrix. This is a unique square resolution, offering a 1:1 aspect ratio, which is perfectly suited for square displays and circular interface emulation. The RGB stripe arrangement provides full color mixing for each pixel.
- Display Characteristics: Capable of displaying up to 16.7M colors. This refers to 8-bit color depth per primary color (R, G, B), allowing the module to generate 16,777,216 distinct colors for the most realistic and smooth color reproduction. The module offers a typical contrast ratio of 800:1 and a response time of 30ms (Typ.). The brightness is 350 cd/m² (Typ.).
- Interface Type: The module utilizes a standard RGB Parallel Interface (18-bit color data lines: D0-D17) along with synchronization signals (VSYNC, HSYNC, DE, PCLK). The module also includes a serial interface (SPI) for initial configuration and command control, using SDA, SCL, and CS pins. This is a common methodology for modern display driver ICs.
- Main LCD Driver IC: The module integrates the ST7701P driver IC. This specific IC is designed to drive the TFT matrix and handle the RGB interface commands, as well as the SPI interface for configuration.
- Backlight Unit: The module utilizes a white LED backlight comprised of 10 chips connected in parallel (并联). The specified driving condition is IF=200mA (Total) and Vf=3.0V (Typ.) per LED. The backlight circuit is shown on the specification, with LEDA (Anode, Pin 1) and LEDK (Cathode, Pins 2, 3) on the FPC connector.
- Special Features: High resolution 16.7M color capability (8-bit), IPS technology for wide viewing angles (ALL), unique square resolution (480×480), compact size (3.95 inch), RGB 18-bit / SPI interface for standard integration, silver dot and yellow insulation paper on FPC for ESD protection, and compliant with the RoHS directive. The module includes a white alignment mark for mechanical positioning and silver adhesive points for grounding. The FPC has PI reinforcement (T=0.3mm total thickness).
- Manufacturer's Mechanical Recommendations: The specification provides several key recommendations: 1) The case visual area should be smaller than the VAmds (Viewing Area) by more than 0.3mm per side. 2) The foam opening for the case should be larger than the VAmds by more than 0.6mm per side. 3) The Q TD edge should not contact any metal conductor.
- Approval Status: Approved Product Specification only (Revision 1.0).
3. Exhaustive Technical Specifications
3.1 General & Mechanical Specification
This section provides the physical dimensions and other key general parameters of the module. The module is compact and features a square active area.
| Parameter | Specification | Unit |
|---|---|---|
| Panel Size | 3.95'' (Diagonal) | Inch |
| Module Outline (H×V×D) | 74.66 × 76.54 × 2.11 | mm |
| Active Area (H×V) | 71.86 × 70.18 | mm |
| Number of Dots | 480(RGB) × 480 | pixels |
| Display Type | Active matrix a-Si TFT, Transmissive, IPS | - |
| Display Colors | 16.7M (24-bit) | colors |
| Module Type | COG+FPC+B/L | - |
| Main LCD Driver IC | ST7701P | - |
| Display Mode | Transmissive, IPS (ALL View Direction) | - |
| View Direction (Best Image) | IPS (ALL View Direction) | - |
| Interface | RGB 18-bit + 3-Wire SPI | - |
| Backlight Type | White LED (10 chips in parallel) | - |
| LCM Thickness | 2.11 ± 0.15 | mm |
| Tolerance of Segment to Edge of Glass | ±0.2 | mm |
3.2 Absolute Maximum Ratings
The absolute maximum ratings are stress limits. Operating the module at or beyond these values can result in irreversible damage.
| Parameter | Symbol | Min | Max | Unit | Remark |
|---|---|---|---|---|---|
| Supply voltage | VCC | -0.3 | 3.6 | V | Note1, Note2 |
| Supply voltage | IOVCC | -0.3 | 3.6 | V | Note1, Note2 |
| Operating temperature | TOPR | -20 | 70 | °C | Note1, Note2 |
| Storage temperature | TSTR | -30 | 80 | °C | Note1, Note2 |
3.3 Electrical Characteristics
These are the recommended operating conditions for the module.
| Item | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply voltage | VCC | 2.5 | 2.8 | 3.6 | V |
| Supply voltage (I/O) | IOVCC | 1.65 | 1.8 | 3.3 | V |
| Input Voltage (L level) | VIL | GND | - | 0.3*IOVCC | V |
| Input Voltage (H level) | VIH | 0.7*IOVCC | - | IOVCC | V |
3.4 Backlight Driving Conditions
The module uses a white LED backlight comprised of 10 chips configured in parallel. The driving condition is: IF=200mA (Total), Vf=3.0V (Typ.) per LED. A constant current source is recommended for driving the backlight to ensure consistent brightness and longevity.
| Parameter | Symbol | Typ | Unit | Condition |
|---|---|---|---|---|
| Forward Voltage (Total) | Vf | 3.0 | V | Per LED chip |
| Forward Current (Total) | If | 200 | mA | Total for all LEDs |
3.5 Interface Connection (40-Pin FPC)
The module uses a 40-pin FPC connector. The interface includes power (VCC, GND), 18-bit data bus (DB0-DB17), synchronization signals (HSYNC, VSYNC, DE, PCLK), control signals (CS, SCL, SDA, RESET, NC), and backlight power (LEDA, LEDK).
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 1 | LEDA | P | Power for LED backlight anode |
| 2, 3 | LEDK | P | Power for LED backlight cathode |
| 4, 34, 40 | GND | P | Ground |
| 5 | VCI | P | Power supply |
| 6 | RESET | I | External reset input |
| 7, 8, 35, 36, 37, 38, 39 | NC | - | Not Connected |
| 9 | SDA | I | Serial data input pin for SPI interface |
| 10 | SCL | I | Serial clock input for SPI interface |
| 11 | CS | I | Chip select signal |
| 12 | PCLK | I | Dot clock signal for DPI (RGB) interface |
| 13 | DE | I | Data enable signal for DPI (RGB) interface |
| 14 | VS | I | Frame synchronizing signal for DPI (RGB) interface |
| 15 | HS | I | Line synchronizing signal for DPI (RGB) interface |
| 16-33 | D0-D17 | I | Data bus (18-bit RGB data: D0-D17) |
3.6 Timing Characteristics (RGB Interface)
The module supports standard RGB interface timing. The specification details timing for VSYNC, HSYNC, ENABLE, DOTCLK, and data bus signals. The typical timing parameters are: DOTCLK Cycle Time (TCYCD) = 33ns (Min.), DOTCLK High-level Pulse Width (PWDH) = 15ns (Min.), VSYNC/HSYNC Setup Time (TSYNCS) = 5ns (Min.), Data Setup Time (TPDS) = 5ns (Min.), Data Hold Time (TPDH) = 5ns (Min.).
| Signal | Symbol | Min | Max | Unit | Description |
|---|---|---|---|---|---|
| HSYNC, VSYNC | TSYNCS | 5 | - | ns | Setup Time |
| ENABLE | TENS | 5 | - | ns | Setup Time |
| ENABLE | TENH | 5 | - | ns | Hold Time |
| DOTCLK | PWDH | 15 | - | ns | High-level Pulse Width |
| DOTCLK | PWDL | 15 | - | ns | Low-level Pulse Width |
| DOTCLK | TCYCD | 33 | - | ns | Cycle Time |
| DOTCLK | Trghr, Trghf | - | 15 | ns | Rise/Fall Time |
| DB | TPDS | 5 | - | ns | Data Setup Time |
| DB | TPDH | 5 | - | ns | Data Hold Time |
3.7 Optical Specifications
The electro-optical characteristics of the module are measured under standard laboratory conditions (Ta=25°C). Key parameters include a luminance of 350 cd/m², a contrast ratio of 800:1 (Typ.), and a response time of 30ms (Typ.). The viewing angle is 80° (Typ.) in all directions for CR>10. The chromaticity coordinates for white are Wx=0.301 and Wy=0.327 (Typ.). The transmittance is 5.5% (Typ.).
| Item | Symbol | Condition | Min. | Typ. | Max. | Unit | Remark |
|---|---|---|---|---|---|---|---|
| Response time | Tr+Tf | θx=θy=0° | - | 30 | 40 | ms | Note 1 |
| Contrast Ratio | CR | θx=θy=0° | 640 | 800 | - | - | Note 2 |
| Transmittance | T% | θx=θy=0° | 5.0 | 5.5 | - | % | - |
| White Chromaticity (CIE1931) | Wx | θx=θy=0° | - | 0.301 | - | - | - |
| White Chromaticity (CIE1931) | Wy | θx=θy=0° | - | 0.327 | - | - | - |
| Viewing angle (CR>10) | θT, θB, θL, θR | CR>10 | - | 80 | - | Deg. | Note 3 |
3.8 Inspection Standards (GB/T 2828-2003)
The module is subject to inspection according to GB/T 2828-2003, normal inspection, Class II. The specification defines AQL (Acceptable Quality Level) for major and minor defects. Detailed inspection criteria include glass defects (cracks, dimensions, chipping), LCD appearance defects (scratches, bubbles, dots, eyewinkers), FPC defects (peeling, no tape, dirty dots), black tape & mara tape defects, and silicon & tuffy glue defects.
| Item | Specification | Standard |
|---|---|---|
| Inspection Standard | Normal Inspection, Class II | GB/T 2828-2003 |
| Inspection Conditions | 30cm distance, 30° incidence, 60W/m² (approx.) | 40W Fluorescent Lamp |
| AQL (Major Defect) | 0.65% | GB/T 2828-2003 |
| AQL (Minor Defect) | 1.5% | GB/T 2828-2003 |
3.9 Inspection Criteria (Examples)
The specification provides detailed criteria for various defect types:
- Glass Defects (Major): Dimension unconformity (by Engineering Drawing). Non-pin-side damage criteria defined by thickness (c) and width (b).
- LCD Appearance Defects (View Area): Scratches/folds on fiber, glass, polarizer (Minor): W > 0.1mm, L > 3.0mm = 0 allowed. Polarizer bubbles/concave/convex (Minor): ψ ≤ 0.2mm disregarded, 0.2mm < W ≤ 0.3mm = 2 allowed, up to ψ > 0.5mm = 1 allowed. Black/dirty dots, impurities (Major): ψ ≤ 0.15mm disregarded, 0.15mm < W ≤ 0.25mm = 2 allowed, up to ψ > 0.3mm = 1 allowed. Polarizer prick (Major): ψ ≤ 0.1mm disregarded, 0.1mm < W ≤ 0.25mm = 3 allowed.
- FPC Defects (Major/Minor): Copper screen peel (Major): Reject. No release tape or peel (Major): Reject. Dirty dot/impurity (Minor): ψ ≤ 0.25mm = 2 allowed, ψ > 0.25mm = 0.
- Black Tape & Mara Tape (Minor/Major): FPC/H/S black tape shift (Minor): shift spec for glue to polarize or IC bare = Reject. No black tape (Major): Reject. Tape position mistake (Minor): Not by engineering drawing = Reject.
- Silicon and Tuffy Glue (Minor): Quantity of silicon: Uncover ITO and circuit area = Reject.
4. Application Scenario
The LS0395I18-R-V1 is a high-performance, compact display module ideal for any embedded system that requires a vibrant, high-resolution display in a unique square format. Its 3.95-inch diagonal size with a 480×480 resolution provides a crisp and detailed image for rich graphical content and text. The 16.7M color capability allows for the most realistic and visually appealing user interface possible with an LCD.
Key application areas are numerous and diverse:
- Smart Home Control Panels: Thermostats, lighting control, security system interfaces benefit from the square aspect ratio for a modern, intuitive interface.
- IoT Edge Terminals: Data loggers, environmental monitors, and smart agriculture display nodes that require a high-quality, square display for status and data visualization.
- Automotive Instrument Clusters: Aftermarket display modules for speedometers, tachometers, and auxiliary information displays.
- Industrial Control Panels: HMIs for machinery and automation that benefit from a visually consistent square display area.
- Medical Devices: Portable diagnostic and monitoring equipment that requires a high-quality display in a compact package.
The module's RGB 18-bit / SPI interface provides flexibility for integration with various host processors. The IPS technology ensures excellent image consistency when viewed from any angle. The manufacturer's specific mechanical recommendations (VA clearance, foam opening, TP isolation) are critical for successful mechanical design integration.
5. Handling Precautions And Compliance
The LCD panel is made of glass and is fragile. The polarizer surface is easily scratched. The module should be handled with care to avoid applying pressure on the display area, especially the back of the LCD. ESD (Electrostatic Discharge) protection is mandatory throughout handling, assembly, and testing. Use grounded wrist straps, conductive work surfaces, and anti-static packaging. The module includes silver adhesive points for grounding (银浆点) and a yellow insulation protective film (黄色绝缘胶纸) on the FPC for ESD protection and structural reinforcement, which should be preserved during handling.
The FPC is delicate; avoid sharp bends at the connector interface. A stiffener (PI补强 T=0.2mm) is applied to the FPC for additional support at the connector. Do not operate or store the module outside the specified environmental conditions. The operating temperature range is -20°C to +70°C, and the storage temperature range is -30°C to +80°C.
Important: The module includes a white LED backlight. A constant current source is strongly recommended for driving the backlight to ensure consistent brightness and longevity. The module's FPC is designed for a specific bending sequence for shipping (弯折出货). Follow the FPC bending diagram carefully. The customer's case foam opening should be smaller than or equal to the dimensions shown in the drawing to avoid light leakage.
The module should be stored in a clean, dry environment away from direct sunlight, high temperatures, and corrosive gases. It is strongly recommended to read the full specification document (LS0395I18-R-V1 Product Specification Revision 1.0) before integration and to test the module under application-specific conditions. The manufacturer disclaims liability for damages resulting from improper use, modification, or failure to follow these guidelines.
The product is compliant with the RoHS (Restriction of Hazardous Substances) directive. Proper waste disposal according to local regulations is recommended at the end of the product's lifecycle.
