LSC0395I21-MP-V1 3.95 Inch TFT-LCD Module 480x480 16.7M Colors
1. Executive Summary & Product Positioning
The LSC0395I21-MP-V1 is a 3.95-inch transmissive type a-Si TFT-LCD (amorphous silicon thin film transistor liquid crystal display) module with an integrated Capacitive Touch Panel (CTP), developed by 立信(万安)智显科技有限公司 (Lesson Smart Display Technology Co., Ltd). The module is composed of a TFT-LCD panel, a driver circuit, a backlight unit, and a CTP. The panel size is 3.95 inch and the resolution is 480(RGB)*480, the panel can display up to 16.7M colors. This module features a COG (Chip-on-Glass) + FPC + B/L (Backlight) + CTP construction and is designed for a wide range of applications requiring a vibrant, square display with touch capability.
Product Positioning: This 3.95-inch module is ideally suited for applications requiring a compact, high-quality display with an integrated touch interface. It is perfect for smart home control panels, IoT devices, handheld instruments, and other embedded systems that require both a vivid display and intuitive user interaction.
2. Detailed Product Overview & Architecture
The module's architecture integrates the display and touch into a single, easy-to-integrate package. The primary components include:
- TFT-LCD Panel: 3.95-inch diagonal, a-Si TFT active matrix, transmissive, IPS (In-Plane Switching). Resolution is 480(RGB) × 480 pixels (square).
- Driver Circuit: The module integrates the ST7701S driver IC, communicating via a MIPI DSI (1-lane) interface.
- Backlight Unit (B/L): A white LED backlight. The typical driving condition is IF=200mA, Vf=3V (TYP).
- Capacitive Touch Panel (CTP): An integrated CTP with an I2C interface, communicating via a dedicated set of pins.
- Mechanical Construction: COG (Chip-on-Glass) + FPC + B/L + CTP. The module size (H×V×D) is 83.26 × 83.26 × 3.19 mm.
- Interface: The module communicates via a 39-pin FPC connector. The display interface is MIPI DSI (1-lane) and the touch interface is I2C.
- Display Mode: Transmissive, IPS.
- Viewing Direction: ALL O'Clock (IPS).
- RoHS: All materials are compliant with RoHS standards.
3. Exhaustive Technical Specifications
3.1 General & Mechanical Specifications
| Item | Specification |
| Display Size (Diagonal) | 3.95 inches |
| Resolution (Dots) | 480(RGB) × 480 |
| Display Technology | Active Matrix TFT, Transmissive, a-Si, IPS |
| Module Construction | COG+FPC+B/L+CTP |
| Color Depth | 16.7M Colors (24-bit) |
| Input Data Interface (Display) | MIPI DSI (1 Data Lane) |
| Input Data Interface (CTP) | I2C |
| Driver IC | ST7701S |
| Module Size (H×V×D) | 83.26 × 83.26 × 3.19 mm |
| Active Area (H×V) | 71.86 × 70.18 mm |
| Display Mode | Transmissive, IPS |
| Viewing Direction | ALL O'Clock (IPS) |
| Backlight Type | White LED (Parallel |
| Touch Panel Type | Capacitive Touch Panel (CTP) |
| Operating Temperature | -20°C to +70°C |
| Storage Temperature | -30°C to +80°C |
| Environmental Compliance | RoHS |
3.2 Absolute Maximum Ratings
Stress beyond those listed may cause permanent damage to the device.
Condition: Ta = -30 to 70 °C, VDDI=1.65V to 3.3V, VCI=2.5 to 3.6V, VSS=0V
| Item | Symbol | Min | Max | Unit | Remark |
|---|---|---|---|---|---|
| Supply voltage | VCC | -0.3 | 4.6 | V | Note1, Note2 |
| Supply voltage | IOVCC | -0.3 | 4.6 | V | Note1, Note2 |
| Operating temperature | TOPR | -20 | 70 | °C | Note1, Note2 |
| Storage temperature | TSTR | -30 | 80 | °C | Note1, Note2 |
3.3 Electrical Characteristics
3.3.1 Recommended DC Characteristics
Condition: VDDI=1.65V to 3.3V, VCI=2.5V to 3.6V, AGND=DGND=0V, Ta=25℃.
| Item | Symbol | Min | Typ | Max | Unit | Remark |
|---|---|---|---|---|---|---|
| Supply voltage | VCC | 2.5 | 2.8 | 3.6 | V | Note1 |
| Supply voltage | IOVCC | 1.65 | 1.8 | 3.3 | V | Note1 |
| Input Voltage (L level) | VIL | VSS | --- | 0.3*IOVCC | V | Note1 |
| Input Voltage (H level) | VIH | 0.7*IOVCC | --- | IOVCC | V | Note1 |
3.3.2 Backlight LED Characteristics
The backlight circuit is a parallel configuration. The typical driving condition is IF=200mA, Vf=3V (TYP).
| Parameter | Symbol | Typ | Unit |
|---|---|---|---|
| Forward Voltage (Total) | Vf | 3.0 | V |
| Forward Current (Total) | IF | 200 | mA |
3.4 Interface Pin Assignment (39-Pin FPC)
The module communicates via a 39-pin FPC connector. The interface combines the MIPI display signals and the I2C touch signals.
3.4.1 Display Interface Pin Description (MIPI DSI & Power)
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 1 | TE | O | Tearing effect output pin. |
| 2 | RESET | I | Reset pin. Active low. |
| 3 | IOVCC | P | I/O power supply (1.65V-3.3V). |
| 4 | VCI | P | Power supply (2.5V-3.6V). |
| 5-11, 14-31 | GND | P | Ground. |
| 6 | D1P | I | MIPI DSI differential data pair (Positive). |
| 7 | D1N | I | MIPI DSI differential data pair (Negative). |
| 9 | CLKP | I | MIPI DSI differential clock pair (Positive). |
| 10 | CLKN | I | MIPI DSI differential clock pair (Negative). |
| 12 | D0P | I/O | MIPI DSI differential data pair (Positive). |
| 13 | D0N | I/O | MIPI DSI differential data pair (Negative). |
| 38 | LEDK | P | Power for LED backlight cathode. |
| 39 | LEDA | P | Power for LED backlight anode. |
3.4.2 Touch Panel Interface Pin Description (I2C)
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 32 | TP_RESET | I | Touch circuit reset pin. |
| 33 | TP_INT | I | Touch screen interrupt line. Active low. |
| 34 | TP_SDA | I | Touch I2C interface data input/output. |
| 35 | TP_SCL | I | Touch I2C interface clock input. |
| 36 | TP_VDD | P | Touch circuit power supply. |
| 37 | TP_GND | P | Touch circuit ground. |
3.5 Interface Timing Characteristics
3.5.1 Reset Input Timing
The reset pin (RESX) has specific timing requirements for proper initialization.
Condition: VDDI=1.8, VDD=2.8, AGND=DGND=0V, Ta=25 ℃.
| Related Pins | Symbol | Parameter | MIN | MAX | Unit |
|---|---|---|---|---|---|
| RESX | TRW | Reset pulse duration | 10 | - | us |
| RESX | TRT | Reset cancel time (for normal operation) | - | 5 | ms |
| RESX | TRT | Reset cancel time (before Sleep Out command) | - | 120 | ms |
3.5.2 MIPI Interface Low Power Mode Timing Characteristics
Condition: VDDI=1.8, VDD=2.8, AGND=DGND=0V, Ta=25 ℃.
| Parameter | Symbol | MIN | MAX | Unit |
|---|---|---|---|---|
| Length of LP state period (MPU to Modul) | TLPXM | 50 | 75 | ns |
| Length of LP-00 state period by host | TLPXH | 40 | 55 | ns |
| Data to clock setup time | tDS | 0.15*UI | - | ps |
| Data to clock hold time | tDH | 0.15*UI | - | ps |
3.6 Inspection Standards
The specification defines detailed inspection criteria for visual and electrical defects. Key points include:
- AQL (Acceptable Quality Level): Based on GB/T 2828-2003, normal inspection, Class II.
- LCD Appearance Defects (View area): Detailed criteria for scratches, fibers, polarizer defects, bubbles, and dots.
- Black Tape & Mara Tape: Criteria for position, peeling, and correctness.
- Dot Defects (Black/White dots): Defined by size and quantity (e.g., a dot < 0.15mm is disregarded; 2 dots between 0.15mm and 0.25mm are acceptable).
3.7 Design Notes from Documentation
- Mechanical Design Recommendations:
- Suggested housing visible area (shell opening) should be 0.3mm smaller than the VAmds (Viewing Area) on each side.
- Suggested housing foam opening should be 0.6mm larger than the VAmds on each side.
- The edge of the Touch Panel (TP) must not contact any metal conductor.
- B/L Driver: The backlight is a parallel configuration with a typical driving condition of 200mA at 3V. A constant current driver for the backlight is required.
- Interface: The module uses a 1-lane MIPI DSI interface for the display and an I2C interface for the touch controller.
- Reset Timing: The reset pin (RESX) must pulse low for at least 10µs to initiate a reset. After releasing reset, wait for the specified 5ms before sending the first command.
- IPS Display: This module features IPS (In-Plane Switching) technology for wide viewing angles (ALL O'Clock).
- RoHS: All materials are ROHS compliant.
4. Application Guidelines & Critical Notes
- Power Supply: The module requires VCI (2.8V typical) and IOVCC (1.8V typical) power supplies. Ensure the power supplies are stable and have low ripple. The backlight requires a separate LEDA/LEDK constant current source.
- Interface: This module uses a standard MIPI DSI (1-lane) protocol for display and I2C for touch. The host processor must be configured for these protocols.
- Touch Panel: The integrated CTP uses an I2C interface (Pins 34-37). The TP interface also requires a reset (TP_RESET) and an interrupt (TP_INT) pin.
- Backlight Driver (External): A constant current driver is required to supply the backlight via the LEDA (Pin 39) and LEDK (Pin 38) pins. The required driving condition is 200mA total current at 3V typical forward voltage.
- Reset: Ensure the RESET pin (Pin 2) is driven low for at least 10µs during power-on. After releasing reset, wait for 5ms before sending the first command.
- Mechanical Mounting: Follow the mechanical design notes for the enclosure and foam opening to ensure proper fit and avoid damage to the TP and LCD.
- MIPI Interface Specifics: For MIPI mode, ensure the DSI clock and data lanes have proper differential impedance (100Ω) and that the lane setup time (tDS) and hold time (tDH) are met.
- Operating Temperature: The module operates from -20°C to +70°C. Satisfactory display performance is only guaranteed within this range.
- Storage: Store the module in a clean environment, free from dust, moisture, and direct sunlight. Storage temperature range is -30°C to +80°C.
- Handling Precautions: Handle the module with care to avoid damage to the glass or FPC. Ground yourself to prevent electrostatic discharge (ESD).
5. Conclusion & Design-In Support
The LSC0395I21-MP-V1 from Lesson Smart Display Technology is a 3.95-inch square IPS TFT-LCD module with an integrated Capacitive Touch Panel and a 1-lane MIPI DSI interface. It features a 480x480 resolution, 16.7M colors, an integrated CTP, a simple interface, and a robust mechanical design. It is a reliable, all-in-one display solution suitable for a wide variety of embedded display applications requiring touch input.
For successful design-in, engineers should:
- Obtain and review the complete, official Product Specification (Revision 1.0) for the full mechanical drawing and the driver IC (ST7701S) and touch IC datasheets for detailed initialization and timing parameters.
- Design a clean 2.8V power supply for the LCD. Design a backlight constant current driver circuit capable of delivering 200mA at up to 3.3V.
- Configure the host processor's MIPI DSI interface to match the timing specifications detailed in this datasheet. Also configure the I2C bus for the touch controller.
- Follow the mechanical design guidelines for the enclosure and foam opening to ensure proper fit and avoid damage to the integrated touch lens.
- Contact the manufacturer for evaluation modules, sample requests, and further technical support during the design-in phase.
This module is designed to provide a reliable and vibrant display solution for a wide array of applications.
