Product Main Title:
LS024I40-S-V1: 2.4-Inch IPS TFT LCD Module, 240x320 Resolution, 262K Colors, SPI Interface
Product Subtitle / Keywords:
2.4 Inch Display, QVGA 240x320 Resolution, Transmissive a-Si IPS TFT, 4-line SPI Interface, COG+FPC+B/L, 262K Colors, Wide Viewing Angle, 4-Chip White LED Backlight
Comprehensive Technical Specification & Application Guide
1. Executive Summary & Product Positioning
The LS024I40-S-V1, developed by LESSON (Wan'an) Zhixian Technology Co., Ltd., is a 2.4-inch transmissive amorphous Silicon TFT-LCD module featuring IPS (In-Plane Switching) technology for wide viewing angles. This product specification book is the definitive technical document, detailing its structural composition (COG+FPC+B/L), mechanical dimensions, absolute maximum ratings, detailed electrical characteristics, 4-line SPI (Serial Peripheral Interface) timing, and comprehensive electro-optical performance. It delivers a QVGA resolution of 240(RGB)×320 with 262K-color display capability. The document provides a complete set of technical indicators and quality control requirements, covering specifications from appearance to electro-optical performance. The unequivocal recommendation for manufacturers and users is to strictly adhere to this specification for design, inspection, and use to ensure module performance and reliability meet the defined standards.
2. Detailed Product Overview & Architecture
- Core Technology: Transmissive-type a-Si TFT-LCD (amorphous silicon thin film transistor liquid crystal display).
- 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 panel, a driver circuit, and a backlight unit.
- Interface: 4-line SPI (Serial Peripheral Interface).
- Viewing Direction: IPS (wide viewing angle).
- Backlight: 4 Chip-White LEDs in series.
- Approval Status: Approved Product Specification only.
3. Exhaustive Technical Specifications
3.1 Mechanical & Physical Specifications
| Item | Specification | Unit |
|---|---|---|
| Module size (H×V×D) | 42.72 × 60.26 × 2.25 | mm |
| Active area (H×V) | 36.72 × 48.96 | mm |
| Number of dots / Resolution | 240(RGB) × 320 | pixel |
| Panel Size (Diagonal) | 2.4 | inch |
Critical Mechanical Design Notes (from document):
- Display Type: Main LCD: Transmissive, IPS.
- Operating Temperature: -20°C ~ +70°C.
- Storage Temperature: -30°C ~ +80°C.
- ROHS Compliance: Yes.
- Backlight: 4 Chip-White LED in series.
- Bezel Opening: It is recommended that the housing's visible area be at least 0.3mm smaller per side than the module's active area (AA).
- Foam Gasket Cutout: Should be at least 0.6mm larger per side than the module's viewing area (VA).
- Metal Contact: The TP (Touch Panel, if applicable) edges must not contact metal conductors.
- Segment to Glass Edge Tolerance: ±0.2 mm.
3.2 Electrical & Interface Specifications
3.2.1 Absolute Maximum Ratings
| Item | Symbol | Min | Max | Unit | Remark |
|---|---|---|---|---|---|
| Supply voltage | VCC | -0.3 | 4.6 | V | Note1, Note2 |
| I/O Supply voltage | IOVCC | -0.3 | 4.0 | V | Note1, Note2 |
| Operating temperature | TOPR | -10 | 70 | °C | Note1, Note2 |
| Storage temperature | TSTR | -20 | 80 | °C | Note1, Note2 |
Notes (interpreted):
- Note1/Note2: Stress beyond these ratings may cause permanent damage; functional operation is not implied under these conditions.
3.2.2 Electrical Characteristics (DC)
| Item | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply voltage (Main) | VCC | 2.4 | 2.75 | 3.3 | V |
| I/O Supply voltage | IOVCC | 1.65 | 1.8 | 3.3 | V |
| Input Voltage (Low level) | VIL | 0 | -- | 0.3 * IOVCC | V |
| Input Voltage (High level) | VIH | 0.7 * IOVCC | -- | IOVCC | V |
3.2.3 Pin Description (12-pin FPC)
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 1 | GND | P | Ground |
| 2 | VCI | P | Power supply |
| 3 | IOVCC | P | Power supply (I/O) |
| 4 | TE | O | Tearing effect signal. Used to synchronize MCU to frame memory writing. |
| 5 | SDA | I/O | Serial data input/output pin |
| 6 | DC | I | Command and Data select pin |
| 7 | SCL | I | Serial clock pin |
| 8 | CS | I | Chip select pin |
| 9 | RESET | I | Reset pin |
| 10 | GND | P | Ground |
| 11 | LEDA | P | Power for LED backlight anode |
| 12 | LEDK | P | Power for LED backlight cathode |
3.2.4 SPI Interface Timing Characteristics (4-line serial)
Conditions: VDDI=1.65 to 3.3V, VDD=2.4 to 3.3V, AGND=DGND=0V, Ta=25°C. Input signal rise/fall time (Tr, Tf) ≤ 15 ns.
| Signal | Symbol | Parameter | MIN | MAX | Unit | Description |
|---|---|---|---|---|---|---|
| CSX | T_CSS | Chip select setup time (write) | TBD | - | ns | |
| CSX | T_CSH | Chip select hold time (write) | TBD | - | ns | |
| CSX | T_CSS | Chip select setup time (read) | TBD | - | ns | |
| CSX | T_SCC | Chip select hold time (read) | TBD | - | ns | |
| CSX | T_CHW | Chip select "H" pulse width | TBD | - | ns | |
| SCL | T_SCYCW | Serial clock cycle (Write) | TBD | - | ns | For write command & data RAM |
| SCL | T_SHW | SCL "H" pulse width (Write) | TBD | - | ns | For write command & data RAM |
| SCL | T_SLW | SCL "L" pulse width (Write) | TBD | - | ns | For write command & data RAM |
(Note: The timing parameters are listed as "TBD" (To Be Determined) in the provided excerpt. The final production specification or a later revision would define concrete values.)
3.2.5 Backlight Unit
- Configuration: 4 Chip-White LEDs in series.
- Drive Condition: Forward Current (I_F) = 20 mA (Typical); Forward Voltage (V_f) = 12 V (Typical).
3.3 Optical & Electro-Optical Characteristics
| Item | Symbol | Condition | Min. | Typ. | Max. | Unit | Remark |
|---|---|---|---|---|---|---|---|
| Response Time | Tr + Tf | θx = θy = 0 | -- | 35 | 40 | ms | Note 1 |
| Contrast Ratio | CR | θx = θy = 0 | 900 | 1200 | -- | -- | Note 2 |
| Transmittance | T% | θx = θy = 0 | 4 | 4.7 | -- | % | Without APF Polarizer |
| Color Chromaticity (White) | W x | θx = θy = 0 | -- | 0.308 | -- | -- | CIE1931 |
| Color Chromaticity (White) | W y | θx = θy = 0 | -- | 0.339 | -- | -- | CIE1931 |
| Viewing Angle (CR>10) | θT, θB, θL, θR | -- | 80 | 85 | -- | Deg. | Note 3 |
Notes (from document):
- Response time (Tr+Tf) is measured by switching the data signal ON/OFF. Tr is 10% to 90% luminance change; Tf is 90% to 10%.
- Contrast Ratio (CR) = (Luminance of white raster) / (Luminance of black raster), measured at panel center, viewing angle Θ=0°.
- Viewing angles (Top, Bottom, Left, Right) are defined where contrast ratio exceeds 10.
4. Application Guidelines & Critical Notes
- Intended Use: Consumer electronics, industrial HMIs, portable devices, instrumentation—applications requiring a small, color display with wide viewing angles and a simple SPI interface.
- Critical Design Considerations:
- Mechanical Integration: Heed the explicit design rules for housing: Bezel opening should be slightly smaller than AA; foam cutout should be larger than VA to avoid pressure-induced Mura.
- Dual Power Supplies: Provide stable VCC (2.4-3.3V) for main logic and IOVCC (1.65-3.3V) for I/O. Ensure they are within the recommended operating range.
- SPI Interface: The host MCU's SPI peripheral must be configured to meet the timing parameters (once defined). The TE pin can optimize frame buffer updates.
- High Voltage Backlight: The backlight uses 4 LEDs in series, requiring a ~12V drive voltage at 20mA. Design a suitable constant-current boost converter or driver circuit.
- Reset Circuit: Ensure the RESET pin receives a proper low pulse during initialization. The power-on/off sequence diagram in the spec should be followed.
- Temperature Ranges: Operate within -10°C to +70°C and store within -20°C to +80°C.
- Quality Inspection: The specification references GB/T 2828-2003 for Acceptable Quality Level (AQL) sampling of major/minor defects, covering glass, FPC, tape, glue, and electrical criteria (e.g., no display, missing line, Mura, overcurrent).
5. Conclusion & Design-In Support
The LS024I40-S-V1 specification details a reliable 2.4-inch IPS SPI display module. Its key strengths are the wide 85-degree viewing angles, clear mechanical integration guidelines, and a standard 4-line SPI interface. The main design focus should be on precise mechanical housing design, providing the dual power supplies, and implementing the 12V LED driver for the series-connected backlight. While some AC timing parameters are TBD in the provided revision, the core electrical and optical specs provide a solid foundation for integration. By following this specification, the module delivers consistent performance for embedded display applications.
