Product Main Title:
LS028T12-M-V1: 2.8-Inch TFT LCD Module, 240x320 Resolution, 262K Colors, Multi-Interface (8-bit 8080/SPI), ST7789P3 Driver, for Embedded Display Applications

Product Subtitle / Keywords:
2.8 Inch TFT Display, QVGA 240x320 Resolution, Transmissive a-Si TFT, TN Viewing Direction, Multi-Interface (8-bit 8080 Parallel / SPI), ST7789P3 Driver IC, COG+FPC+B/L, 262K Colors, -20°C to +70°C Operation, Detailed Interface Timing & Pinout

Comprehensive Technical Specification & Application Guide

1. Executive Summary & Product Positioning

The LS028T12-M-V1, developed by LESSON (Wan'an) Zhixian Technology Co., Ltd., is a versatile 2.8-inch transmissive amorphous Silicon TFT-LCD module. This product specification book serves as the definitive technical document, meticulously defining its structural composition (COG+FPC+B/L), mechanical dimensions, absolute maximum ratings, detailed electrical characteristics, and comprehensive interface timing for multiple protocols including 8-bit 8080 MCU parallel and SPI serial interfaces. It delivers a QVGA resolution of 240(RGB)×320 with 262K-color display capability, driven by the ST7789P3 controller. The unequivocal recommendation for engineering personnel is to use the parameters in this specification for power configuration, interface adaptation, and display performance evaluation during development to ensure compatibility and that the module's performance meets the defined targets.

2. Detailed Product Overview & Architecture

• Core Technology: Transmissive-type a-Si TFT-LCD.
• Display Characteristics: Capable of displaying up to 262K colors.
• Module Construction: COG (Chip-On-Glass) + FPC (Flexible Printed Circuit) + B/L (Backlight Unit). Composed of a TFT-LCD panel, a driver circuit, and a backlight unit.
• Interface Flexibility: Supports multiple host interfaces configurable via IM[3:0] pins:
  • 8-bit 8080-series MCU Parallel Interface
  • SPI (Serial Peripheral Interface)
  • 3-line 9-bit Serial Interface
  • 2-data-lane Serial Interface
  • 4-line 8-bit Serial Interface
• Viewing Direction: TN (Twisted Nematic), with grayscale inversion characteristics.

3. Exhaustive Technical Specifications

3.1 Mechanical & Physical Specifications

• Panel Size (Diagonal): 2.8 inches
• Active Area (H×V): 43.2 mm × 57.6 mm
• Module Size (H×V×D): 50.0 mm × 69.1 mm × 2.3 mm
• Resolution: 240 (RGB) × 320 pixels
• Display Mode: Active matrix TFT, Transmissive type
• Drive IC: ST7789P3

3.2 Optical & Electro-Optical Characteristics (Ta=25°C, Typical)

• Response Time (Tr+Tf): 16 ms (Typical)
• Contrast Ratio (CR): 500 (Typical) @ center, θx=θy=0°
• Transmittance (T%): 6.4% (Typical)
• Color Chromaticity (White): W x ≈ 0.301, W y ≈ 0.337 (Typical).
• Viewing Angle (CR>10): Top (θT): 45°, Bottom (θB): 45°, Left (θL): 50°, Right (θR): 20° (Typical).
• Luminance (L): 350 cd/m² (Typical) @ Backlight Forward Current (IF)=80mA.

3.3 Electrical & Interface Specifications

3.3.1 Absolute Maximum Ratings

3.3.2 Pin Description (24-pin FPC, Excerpt)

Interface Mode Selection (IM3, IM2, IM1, IM0):

• 0000: 80-8bit parallel I/F (DB[7:0])
• 0101: 3-line 9bit serial I/F (SDA: in/out)
• 0110: 2 data lane serial I/F (SDA: in/out, WRX: in)
• 0110: 4-line 8bit serial I/F (SDA: in/out)
  (Note: The provided table has some apparent duplication/conflict for code 0110. Consult the full document for clarification.)

3.3.3 Critical Interface Timing Characteristics

The specification provides detailed timing parameters for all interfaces, though specific Min/Max values are listed as "TBD" (To Be Determined) in the provided excerpts. The structure is complete:

• 8080 Parallel Interface Timing: Parameters include Address setup/hold (T_AST, T_AHT), Chip Select pulse width/setup/hold (T_CHW, T_CS, T_CSH), Write/Read cycle and pulse durations (T_WC, T_WRH, T_RC, T_RDH), and Data setup/hold (T_DST, T_DHT).
• 3-Line & 4-Line Serial Interface Timing: Parameters include Chip Select setup/hold (T_CSS, T_CSH), SCL clock cycle and H/L pulse widths for Write/Read (T_SCYCW, T_SHW, T_SLW, T_SCYCR, T_SHR, T_SLR), and data setup/hold (T_SDS, T_SDH).
• Reset Timing: Reset pulse duration (T_RW) ≥ 10us. Reset cancel time (T_RT) has two notes: ≤5ms (Note 1,5) and ≤120ms (Note 1,6,7).
• General Signal Notes: Input signal rise/fall time (Tr, Tf) should be 15 ns or less. Logic high/low levels are defined as 70%/30% of VDDI.

3.3.4 Backlight Unit

• Drive Condition: Forward Current (IF) = 80mA (Typical), Forward Voltage (Vf) = 3V (Typical).

4. Application Guidelines & Critical Notes

• Intended Use: Embedded systems, portable devices, industrial controls, consumer interfaces—applications requiring a small color display with interface flexibility.
• Critical Design Considerations:
  1. Interface Selection & Configuration: Properly set the IM[3:0] pins at the hardware design stage for the desired interface. Unused control pins (e.g., WR, RD, RS if not in SPI mode) should be fixed at VDDI or DGND as per pin description.
  2. Power Supply: Provide a stable 2.8V supply (VDD). Ensure IOVCC logic level compatibility with the host controller.
  3. Timing Compliance: Once the TBD timing parameters are finalized, ensure the host controller meets the setup, hold, and cycle times for the selected interface.
  4. Reset Circuit: Implement a proper reset circuit. Ensure the reset pulse (RESX) meets the minimum 10us duration and observe the reset cancel timing.
  5. Backlight Driver: Use a constant-current driver circuit capable of providing 80mA.
• Handling: Observe standard ESD precautions.

5. Conclusion & Design-In Support

The LS028T12-M-V1 specification provides a solid foundation for integrating a flexible 2.8-inch display. Its key strength is the support for multiple industry-standard interfaces via hardware configuration, allowing adaptation to various host platforms. Successful implementation requires careful attention to interface mode selection, proper termination of unused pins, and adherence to the final timing specifications once they are determined. By using this document for power, interface, and performance planning, engineers can effectively integrate this module into their embedded display applications.