Product Subtitle / Keywords:
2.8 Inch Display, 240(RGB)×320 Resolution, Transmissive a-Si TFT-LCD, RGB/MCU8BIT/16BIT/SPI4W/3W Interface, COG+FPC+B/L, 262K Colors, ST7789T3 Driver, 50.00×69.20×2.3 mm, 300 cd/m² Luminance, 4 White LEDs, ALL Viewing Direction, -20°C~70°C Operating Temperature

1. Executive Summary & Product Positioning

The LS028I09-X-V1, developed by Lixin (Wan'an) Intelligent Display Technology Co., Ltd. (立信(万安)智显科技有限公司), is a 2.8-inch transmissive color active matrix TFT (Thin Film Transistor) liquid crystal display (LCD) that uses amorphous silicon TFT as a switching device.

This product specification (Revision 1.0, Module Type: COG+FPC+B/L) serves as the definitive technical document, defining its structural composition (COG+FPC+B/L), physical features, mechanical dimensions, absolute maximum ratings, detailed electrical characteristics, complete RGB/MCU8BIT/16BIT/SPI4W/3W interface pinout and timing, and comprehensive electro-optical performance. It delivers a resolution of 240(RGB)×320 with 262K-color display capability, driven by the ST7789T3 controller.

The document provides the core parameters necessary for system integration into compact embedded display applications. The unequivocal recommendation for engineers is to strictly adhere to the electrical specifications, interface timing, and mechanical tolerances described herein to ensure reliable performance and compatibility.

2. Detailed Product Overview & Architecture

• Core Technology: Transmissive-type color active matrix TFT (Thin Film Transistor) liquid crystal display (LCD) that uses amorphous silicon TFT as a switching device.
• Display Mode: Active matrix TFT-LCD module (TFT-LCD panel, driver IC and FPC), a back-light unit.
• Display Format: Graphic 240(RGB)×320 Dot-matrix.
• Display Characteristics: Capable of displaying up to 262 thousand colors.
• Module Construction: COG (Chip-On-Glass) + FPC (Flexible Printed Circuit) + B/L (Backlight Unit). Composed of a TFT-LCD module (TFT-LCD panel, driver IC and FPC), a back-light unit.
• Input Data: RGB/MCU8BIT/16BIT/SPI4W/3W 兼容.
• Viewing Direction (Grayscale Inversion): ALL.
• Drive IC: ST7789T3.
• Approval Status: ☑ Approved Product Specification only (as per signature block).

3. Exhaustive Technical Specifications

3.1 Mechanical & Physical Specifications

Critical Mechanical Design Notes (from outline dimension drawing):

1. Display Type: TFT BOE 2.8"-LCD.
2. Resolution: 240*(RGB)*320.
3. Viewing Direction: ALL.
4. Operating Temperature: -20°C ~ 70°C.
5. Storage Temperature: -30°C ~ 80°C.
6. Backlight: 4 White LEDs In Parallels.
7. General Tolerance: ±0.20 mm.
8. Angular Tolerance: ∠ ±1/4°.
9. FPC Total Thickness: PI补强+FPC总厚度T=0.3±0.03mm.
10. Backlight Thickness: BL 2.3±0.2mm.
11. Polarizer Thickness: POL 0.15mm.
12. Silver Paste Points: Present on the module.
13. Yellow Insulation Paper: Included for handling during assembly.
14. Release Tape/Sticker: Included (易撕贴).
15. Alignment Mark: White alignment line (白色对位线).
16. Backlight Circuit: Voltage 2.8-3.0V, Current: 80MA.
17. Customer LOGO: Indicated on the drawing.

3.2 Electrical & Interface Specifications

3.2.1 Absolute Maximum Ratings

(Ta=25±2°C, Vss=GND=0V)

3.2.2 Electrical Characteristics (DC – Recommended Operating Conditions)

(Ta=25±2°C)

3.2.3 Backlight Unit Characteristics

The back-light system is an edge-lighting type with 4 white LEDs.

(Ta=25±2°C)

Note:
(1) The “LED life time” is defined as the module brightness decrease to 50% of original brightness at $I_L=80mA$. The LED life time could be decreased if operating $I_L$ is larger than 80mA.

Backlight Circuit Diagram:

K1 K2 K3 K4
Voltage 2.8-3.0V
Current: 80MA

3.2.4 Serial Interface Characteristics (3-line serial)

Conditions: VDD1=1.65 to 3.3V, VDD=2.4 to 3.3V, AGND=DGND=OV, Ta=-30 to 70 °C.

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.

3.2.5 Serial Interface Characteristics (4-line serial)

Conditions: VDD=1.65 to 3.3V, VDD=2.4 to 3.3V, AGND=DGND=0V, Ta=-30 to 70 °C.

3.3 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. (Ta=25±2°C)

Notes (from document):

Note (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.

$$\text{ Luminance Uniformity}=\frac{\text{ Min Luminance of white among 9-points}}{\text{ Max Luminance of white among 9-points}}\times 100\%$$

Note (4) Definition of Response time: Sum of Response time:** Sum of Tr and Tf.

Note (5) Definition of Viewing Angle: The viewing angle range that the CR≥10.

3.4 Reliability Test Conditions

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.

3.5 Version Record

(Not explicitly provided in the extracted document excerpt; refer to the REVISION HISTORY section of the full specification.)

4. Application Guidelines & Critical Notes

Intended Use

• Smartwatches, fitness trackers, and other wearable devices
• IoT display nodes and smart home controls
• Miniature handheld instruments
• Any application requiring a compact display with standard resolution

Critical Design Considerations

1. Multi-Interface Support (RGB/MCU8BIT/16BIT/SPI4W/3W):

   • This module supports multiple interface modes: RGB, MCU 8BIT, MCU 16BIT, SPI 4-Wire, and SPI 3-Wire.
   • The host MCU must support the selected interface mode.
   • The document provides detailed timing characteristics for the 3-line serial and 4-line serial interfaces.

2. Power Supply:

   • Provide stable VCI (2.45V to 3.3V, 2.75V typical) for the main logic.
   • Provide stable IOVCC (1.65V to 3.3V, 1.8V typical) for the I/O interface.
   • The backlight requires a constant-current LED driver connected to the backlight pins (K1-K4 for cathode, A for anode), set to 80 mA at approximately 2.8-3.0V.

3. Mechanical Integration:

   • Module Outline: 50.00mm (H) × 69.20mm (V) × 2.3mm (D).
   • Active Area: 43.20mm × 57.60mm.
   • FPC: The module uses a multi-pin FPC.
   • FPC Total Thickness: PI补强+FPC总厚度T=0.3±0.03mm.

4. Viewing Angle Characteristics:
   This module provides ALL viewing direction:

   • Top (12 o'clock): 80° (Typ)
   • Bottom (6 o'clock): 80° (Typ)
   • Left (9 o'clock): 80° (Typ)
   • Right (3 o'clock): 80° (Typ)

5. Optical Performance:

   • **Luminance: 250 cd/m² (Min), 300 cd/m² (Typ) – high brightness for good readability.
   • Contrast Ratio: 250 (Min), 300 (Typ).
   • Response Time: 30ms (Typ), 35ms (Max).
   • LED Life Time: 20,000 Hrs (Min), 25,000 Hrs (Typ).
   • Color Chromaticity (CIE 1931): Detailed specifications for White, Red, Green, and Blue are provided in the optical characteristics table.

6. Temperature Limits:

   • Operating Temperature: -20°C to +70°C.
   • Storage Temperature: -30°C to +80°C.

Handling & Compliance

• Observe standard ESD precautions during handling and assembly.
• The module contains fragile glass and an FPC – handle with care.
• Avoid bending the FPC sharply, especially near the connector interface.
• The module has a total thickness of 2.3mm – be careful when handling to avoid flexing.
• The module includes a yellow insulation paper and release tape/sticker for handling during assembly.

5. Conclusion & Design-In Support

The LS028I09-X-V1 specification details a versatile 2.8-inch display module with multi-interface support (RGB/MCU8BIT/16BIT/SPI4W/3W) and ST7789T3 driver — an excellent choice for applications requiring interface flexibility and standard resolution.

Key Strengths:

1. Multi-Interface Support: The module supports RGB, MCU 8BIT, MCU 16BIT, SPI 4-Wire, and SPI 3-Wire interfaces, providing maximum flexibility for different system architectures.

2. Standard Resolution (240x320): Suitable for simple icons, text, and basic UIs.

3. High Brightness: 300 cd/m² (Typ) ensures good readability in indoor conditions.

4. Long LED Life Time: 25,000 Hrs (Typ) ensures long-term reliability.

5. Wide Operating Temperature Range: -20°C to +70°C for operation and -30°C to +80°C for storage.

6. ALL Viewing Direction: Provides consistent image quality from multiple perspectives.

Main Design Focus:

• The critical design task is selecting and properly implementing the correct interface mode (RGB, MCU 8BIT, MCU 16BIT, SPI 4W, or SPI 3W) based on the host system's capabilities.
• Supporting requirements:
  • Provide stable VCI (2.75V typical) and IOVCC (1.8V typical) power.
  • Provide a constant-current backlight driver set to 80 mA at 2.8-3.0V.
  • Mechanical integration — the module outline is 50.00mm × 69.20mm × 2.3mm.
  • FPC connector — verify the multi-pin FPC.

This module is an excellent choice for designs requiring a standard 2.8-inch display with flexible interface options, such as industrial control panels, IoT devices, and miniature instruments.