LS028T22-S-V1 2.8 inch TFT-LCD Module 240x320 262k Colors TN
1. Executive Summary & Product Positioning
The LS028T22-S-V1 is a 2.8-inch transmissive type a-Si TFT-LCD (amorphous silicon thin film transistor liquid crystal display) module developed by 立信(万安)智显科技有限公司 (Lesson Smart Display Technology Co., Ltd). It is composed of a TFT-LCD panel, a driver circuit, and a backlight unit. The panel size is 2.8 inch and the resolution is 240(RGB)*320, the panel can display up to 262k colors.
Product Positioning: This module features a 2.8-inch TN (Twisted Nematic) panel, offering a cost-effective display solution with specific viewing direction (12:00). With a standard SPI (4-Line Serial) interface, it is well-suited for a wide range of applications such as industrial HMI, consumer electronics, and other embedded display systems requiring a reliable and budget-friendly display.
2. Detailed Product Overview & Architecture
The module's architecture is designed for robust performance and easy integration. The primary components include:
- TFT-LCD Panel: 2.8-inch diagonal, a-Si TFT active matrix, transmissive, TN mode. Resolution is 240(RGB) × 320 pixels. The active area is 43.2 (H) × 57.6 (V) mm.
- Driver Circuit: The module integrates a driver circuit, communicating via an SPI (4-Line Serial) Interface.
- Backlight Unit (B/L): A white LED backlight with 4 Chip-White LEDs configured in parallel. The typical driving condition is IF=80mA, Vf=3V (TYP).
- Mechanical Construction: COG (Chip-on-Glass) + FPC (with PI reinforcement, total thickness ~0.30mm) + B/L. The total module thickness is 2.32±0.2 mm.
- Interface: The module communicates via a 10-pin FPC connector. The display interface is 4-Line SPI (Serial Interface).
- Display Mode: Active matrix TFT, Transmissive type, TN.
- Viewing Direction (Grayscale Inversion): 12:00 (TN).
3. Exhaustive Technical Specifications
3.1 General & Mechanical Specifications
| Item | Specification |
| Display Size (Diagonal) | 2.8 inches |
| Resolution (Dots) | 240(RGB) × 320 |
| Display Technology | Active Matrix TFT, Transmissive, a-Si, TN |
| Module Construction | COG+FPC+B/L |
| Color Depth | 262K Colors |
| Viewing Direction (Grayscale Inversion) | 12:00 (TN) |
| Input Data Interface | 4-Line SPI |
| Module Size (H×V×D) | 50.0 × 69.2 × 2.32 mm |
| Active Area (AA, H×V) | 43.2 × 57.6 mm |
| Pixel Arrangement | RGB Dot-matrix (240(RGB)×320) |
| Display Mode | Transmissive, TN |
| Backlight Type | 4 Chip-White LED, Parallel |
| Operating Temperature | -20°C to +70°C |
| Storage Temperature | -30°C to +80°C |
3.2 Absolute Maximum Ratings
Stress beyond those listed may cause permanent damage.
| Item | Symbol | Min | Max | Unit | Remark |
|---|---|---|---|---|---|
| Supply voltage | VCC | -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 Operating Conditions
Condition: Ta=25°C.
| Item | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply voltage | VCC | 2.4 | 2.75 | 3.3 | V |
| Input Voltage "L" level | VIL | 0 | --- | 0.3*IOVCC | V |
| Input Voltage "H" level | VIH | 0.7*IOVCC | --- | IOVCC | V |
3.3.2 Backlight LED Characteristics
The backlight consists of 4 Chip-White LEDs in Parallel. The backlight drive condition is IF=80mA, Vf=3V (TYP).
| Parameter | Symbol | Typ | Unit |
|---|---|---|---|
| Forward Voltage | Vf | 3.0 | V |
| Forward Current (Total) | IF | 80 | mA |
3.4 Interface Pin Assignment (10-Pin FPC)
Connector: 10-pin FPC. Interface: 4-Line SPI (Serial Interface).
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 1 | GND | P | Ground |
| 2 | RS | I | Command and Data select pin |
| 3 | CS | I | Chip select pin |
| 4 | SCL | I | Serial clock pin |
| 5 | SDA | I/O | Serial data input/output PIN |
| 6 | RESET | I | Reset pin. |
| 7 | VCC | P | power supply |
| 8 | GND | P | Ground |
| 9 | LEDA | P | Power for LED backlight anode |
| 10 | LEDK | P | Power for LED backlight cathode |
3.5 Electro-Optical Characteristics
| Item | Symbol | Condition | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|---|
| Response time | Tr + Tf | θx = θy =0 | --- | 16 | --- | ms |
| Contrast Ratio | CR | θx = θy =0 | --- | 500 | --- | --- |
| Viewing angle (CR>10) | θT (Top) | --- | --- | 50 | --- | Deg. |
| --- | θB (Bottom) | --- | --- | 20 | --- | Deg. |
| --- | θL (Left) | --- | --- | 45 | --- | Deg. |
| --- | θR (Right) | --- | --- | 45 | --- | Deg. |
3.6 Timing Characteristics
The timing parameters for the 4-line serial interface are listed as TBD (To Be Determined) in the provided specification excerpt. For precise timing, please consult the official datasheet and the driver IC manufacturer's documentation.
The timing section describes the 4-line serial interface timing characteristics and the reset timing. The reset pulse duration (TRW) must be at least 10 µs.
3.7 Design Notes from Documentation
- B/L Driver: The backlight driving condition is IF=80mA, Vf=3V (TYP) for 4 parallel LEDs.
- Mechanical: Tolerance of segments to edge of glass: ±0.2mm. The FPC includes PI reinforcement with a total thickness of 0.3mm (FPC+PI). Yellow insulating tape is used for protection. An easy-tear sticker is provided for FPC handling.
- Housing: It is recommended that the housing visual area be at least 0.3mm smaller than the VA on each side. The housing foam window should be at least 0.6mm larger than the VA on each side. The TP edge should not contact metal conductors to avoid ESD or short circuit risks.
- RoHS: RoHS compliance is expected.
4. Application Guidelines & Critical Notes
- Power Supply: The module requires a 2.75V (Typ.) power supply for VCC. Ensure the power supply ripple is minimized.
- Interface: This module uses a standard 4-Line SPI (Serial Interface) protocol. The host microcontroller must be configured for this protocol, managing signals such as CS, RS, SCL, and SDA.
- Backlight Driver (External): An external constant current driver is required to supply a typical total current of 80mA at a forward voltage of 3.0V.
- Reset: A hardware reset pin (RESET, Pin 6) is provided. A low pulse of at least 10µs is required for a valid reset.
- 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 LS028T22-S-V1 from Lesson Smart Display Technology is a 2.8-inch TN TFT-LCD module with a 4-Line SPI interface. It is a standard-resolution, cost-effective display solution suitable for a wide variety of embedded display applications.
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 datasheet for detailed command initialization and timing parameters.
- Design a clean 2.75V power supply and a backlight constant current driver circuit capable of delivering 80mA at 3.0V.
- Configure the host MCU's SPI interface to match the 4-Line serial protocol.
- 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.
