LSC024T35-S-V1: 2.4-Inch TN TFT LCD Module, 240×320 Resolution, SPI Interface, Capacitive Touch Panel (CTP)
Product Subtitle / Keywords
2.4 Inch Display, 240(RGB)×320 Resolution, a-Si TFT-LCD Module, Transmissive, COG+FPC+B/L+CTP Module Type, ST7789P3 Driver IC, 4 Chip-White LEDs Backlight (Parallel), 262k Display Colors, TN (Twisted Nematic) Display Mode, SPI Interface, View Direction 12:00 O'clock (Grayscale Inversion), 30ms Response Time (Typ), 250:1 Contrast Ratio (Typ), Operating Temperature -20°C to +70°C, Storage Temperature -30°C to +80°C, Supply Voltage IOVCC=3.3V (Typ), VDD=2.8V (Typ), Backlight Driving Condition IF=80mA, Vf=3V (Typ), RoHS Compliant, Product Spec Revision 1.0, Lesson Smart Display Technology Co., Ltd.
1. Executive Summary & Product Positioning
The LSC024T35-S-V1, developed by Lesson Smart Display Technology Co., Ltd. (立信(万安)智显科技有限公司), is a transmissive type a-Si TFT-LCD (amorphous silicon thin film transistor liquid crystal display) module, which is composed of a TFT-LCD panel, a driver circuit and a backlight unit. The panel size is 2.4 inch and the resolution is 240(RGB)*320, the panel can display up to 262k colors. The module type is COG+FPC+B/L+CTP.
This product specification (Revision 1.0) serves as the definitive technical document, defining the module's general description, physical features (including display mode, display format, input data, viewing direction, and drive IC), mechanical specification (including module size, number of dots, and active area), outline dimension (including detailed mechanical drawings for both LCM and CTP+LCM, notes on operating/storage temperature, backlight driving conditions, and RoHS compliance), absolute maximum ratings (for supply voltage, operating temperature, and storage temperature), electrical characteristics (including recommended operating conditions for power supplies and logic levels), pin description (for the 21-pin main interface and 4-pin CTP interface), timing characteristics (for the 4-line serial interface), electro-optical characteristics (including response time, contrast ratio, transmittance, luminance, chromaticity, and viewing angles), and inspection standards (including AQL, glass, FPC, black tape, Mara tape, silicon glue, and polarizer scratch defect criteria).
The document provides the core parameters necessary for system integration into standard 2.4-inch portrait-oriented display applications. The unequivocal recommendation for engineers is to strictly adhere to the mechanical and electrical specifications described herein to ensure reliable performance and compatibility.
2. Detailed Product Overview & Architecture
- Core Technology: Transmissive type a-Si TFT-LCD (amorphous silicon thin film transistor liquid crystal display) module, which is composed of a TFT-LCD panel, a driver circuit and a backlight unit. The panel can display up to 262k colors.
- Display Resolution: QVGA: 240(RGB) × 320 pixel array.
- Display Mode: TN (Twisted Nematic) with a view direction of 12:00 o'clock (Grayscale Inversion).
- Module Construction: COG+FPC+B/L+CTP (Chip-On-Glass + Flexible Printed Circuit + Backlight + Capacitive Touch Panel).
- Interface Type: The module uses a 4-line Serial Interface (SPI) for data and command communication.
- Power Architecture: Requires dual power supplies: VDD (2.8V Typ for the core/logic) and IOVCC (3.3V Typ for the I/O interface). The backlight is powered separately through dedicated LED_A and LED_K pins.
- Backlight: White LED backlight consisting of 4 Chip-White LEDs in parallel. The driving condition is specified as IF=80mA, Vf=3V (TYP).
- Touch Panel: The module includes a Capacitive Touch Panel (CTP) with a dedicated interface. The touch controller IC is CST816D. The CTP interface uses I²C signals (CTP_SCL, CTP_SDA) with an interrupt (CTP_INT) and reset (CTP_RST). The CTP has an OGS (One Glass Solution) structure with surface hardness >6H and transmittance ≥85%.
- Driver IC: ST7789P3.
- Supplier: 立信(万安)智显科技有限公司 (Lesson Smart Display Technology Co., Ltd).
3. Exhaustive Technical Specifications
3.1 Mechanical & Physical Specifications
| Item | Specification | Unit |
|---|---|---|
| Model | LSC024T35-S-V1 | - |
| LCD Size (Diagonal) | 2.4 | inch |
| Resolution | 240(RGB) × 320 | pixels |
| Module size (H×V×D) - LCM only | 49.5 × 76.00 × 3.18 | mm |
| Module size (H×V×D) - CTP+LCM | 49.50 × 76.00 × 3.18 (Total thickness 3.18±0.2mm) | mm |
| Active area (H×V) | 36.72 × 48.96 | mm |
| Number of dots | 240(RGB) × 320 | pixel |
| Display Type | TN (Transmissive) | - |
| Module Type | COG+FPC+B/L+CTP | - |
| Touch Panel Structure | OGS (One Glass Solution) | - |
| Touch IC | CST816D | - |
| Supplier | 立信(万安)智显科技有限公司 (Lesson Smart Display Technology Co., Ltd) | - |
3.2 Interface & Electrical Specifications
3.2.1 Absolute Maximum Ratings (From Section 5)
| Item | Symbol | Min | Max | Unit |
|---|---|---|---|---|
| Supply voltage | VDD | -0.3 | 4.6 | V |
| Operating temperature | TOPR | -20 | 70 | °C |
| Storage temperature | TSTR | -30 | 80 | °C |
3.2.2 Recommended Operating Conditions (From Section 6)
| Item | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply voltage | VDD | 2.4 | 2.8 | 3.3 | V |
| Input Voltage 'L' level | VIL | 0 | --- | 0.3*IOVCC | V |
| Input Voltage 'H' level | VIH | 0.7*IOVCC | --- | IOVCC | V |
3.2.3 Pin Description (21-Pin Main Interface + 4-Pin CTP, From Section 7-2)
The module uses a 21-pin FPC connector for the main display interface and a separate 4-pin interface for the CTP (though the drawing shows CTP pins integrated in the main connector). Key signals include:
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 1 | LED_K | P | Power for LED backlight cathode |
| 2 | LED_A | P | Power for LED backlight anode |
| 3 | GND | P | Ground |
| 4 | MOSI | I/O | Serial data input |
| 5 | SCLK | I | Serial interface clock |
| 6 | GND | P | Ground |
| 7 | A0 | I | Display data/command selection pin |
| 8 | CS | I | Chip select pin |
| 9 | RST | I | Reset signal |
| 10 | TE | O | Tearing effect output pin to synchronize MPU to frame writing, activated by S/W command. |
| 11 | IOVCC | P | Power Supply |
| 12 | VDD | P | Power Supply |
| 13-14, 20-21 | MESH0-3 | NC | No Connection |
| 15 | CTP_VDD | P | Power Supply for CTP (3.3V) |
| 16 | CTP_SCL | I | SCL pin for TP (I²C clock) |
| 17 | CTP_SDA | I/O | SDA pin for TP (I²C data) |
| 18 | CTP_INT | I | Interrupt signal for TP |
| 19 | CTP_RST | I | Reset Pin for TP |
3.3 Timing Characteristics (From Section 7.4)
3.3.1 4-line Serial Interface Timing - Table
The specification provides timing parameters for the 4-line serial interface. Note: The document has these parameters marked as "TBD" (To Be Determined). The designer must consult the ST7789P3 driver IC datasheet for the actual timing values. The parameters include Chip Select setup/hold times, Serial Clock cycle/pulse widths, D/CX setup/hold times, and Data setup/hold times.
3.4 Electro-Optical Characteristics (From Section 8)
| Item | Symbol | Condition | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|---|
| Response time | Tr + Tf | θx = θy =0 | --- | 30 | --- | ms |
| Contrast Ratio | CR | θx = θy =0 | --- | 250 | --- | - |
| Transmittance | T% | θx = θy =0 | 4.0 | 4.7 | --- | % |
| Color Chromaticity (White) CIE1931 | W x | θx = θy =0 | --- | 0.308 | --- | - |
| Color Chromaticity (White) CIE1931 | W y | θx = θy =0 | --- | 0.325 | --- | - |
| Viewing angle (Top/T) | θT | CR > 10 | --- | 45 | --- | Deg. |
| Viewing angle (Bottom/B) | θB | CR > 10 | --- | 20 | --- | Deg. |
| Viewing angle (Left/L) | θL | CR > 10 | --- | 45 | --- | Deg. |
| Viewing angle (Right/R) | θR | CR > 10 | --- | 45 | --- | Deg. |
| Luminance (IF = 80mA) | L | - | --- | TBD | --- | cd/m² |
3.5 Backlight Driving Conditions
The backlight circuit from the outline drawing notes: IF=80mA, Vf=3V (TYP). This indicates 4 LEDs in parallel, requiring a constant current driver capable of delivering 80mA at approximately 3V. The total backlight power is 80mA × 3V = 240mW.
3.6 Inspection Standards (From Section 9)
The specification details the quality inspection criteria, based on GB/T 2828-2003; normal inspection, Class II. Key criteria include:
- AQL (Acceptable Quality Level): Major Defect: 0.65, Minor Defect: 1.5.
- Basic Inspection Conditions: The LCM face to us, in normal environment, about an angle of incidence 30°, a distance of 30cm with normal eye, with an angle of 45° to check the products without uncovering the film.
- Glass Defect Criteria: Specifies acceptable limits for cracks (reject), glass extrusion (minor defect: b ≤ 1/3 Pin width for non-bonding area, ≤ 0.5mm for bonding area), and damage to conductive/non-conductive areas.
- FPC Defect Criteria: Copper screen peel is a major defect. No release tape or peel is a major defect. Dirty dots on FPC are allowed only within specific sizes (ψ≤0.25mm: 2 allowed, ψ>0.25: 0 allowed).
- Black Tape & Mara Tape Defect: Tape shifts are minor defects, no black tape is a major defect, tape position mistakes are minor defects.
- Fiber/Glass Scratch, Polarizer Scratch: Scratches are allowed based on width and length (W≤0.03mm: disregard, 0.03mm
4. Application Guidelines & Critical Notes
Intended Use
- Standard 2.4-inch portrait-oriented display applications (e.g., smart home panels, industrial handhelds, IoT devices).
- Systems requiring a QVGA (240×320) resolution with a standard TN display.
- Applications requiring a built-in capacitive touch panel (CTP) with an OGS structure for durability and clarity.
- Systems utilizing an SPI interface for display communication.
Critical Design Considerations
- Dual Power Supply (VDD=2.8V for Core, IOVCC=3.3V for I/O): The module requires a stable 2.8V supply for the core/analog circuitry and a separate 3.3V supply for the I/O interface. The logic thresholds (VIL, VIH) are referenced to IOVCC. Ensure the host processor's SPI I/O voltage is compatible (typically 3.3V).
- SPI Interface (4-line Serial): The module uses a standard 4-line SPI interface. The signals are MOSI (Master Out Slave In), SCLK (Serial Clock), A0 (Data/Command), and CS (Chip Select). Note that there is no MISO pin; data is written serially. The TE pin can be used for tearing effect synchronization.
- External Backlight Driver (80mA @ 3V): The backlight consists of 4 LEDs in parallel, requiring a constant current driver capable of delivering 80mA at a forward voltage of 3V (Typ). The total backlight power is approximately 240mW.
- I²C Capacitive Touch Panel Interface: The CTP uses an I²C interface (CTP_SCL, CTP_SDA) with a dedicated reset pin (CTP_RST) and an interrupt output (CTP_INT). The touch controller IC is CST816D. The host must initialize the touch controller by providing a reset pulse and then communicate over I²C to configure and read touch data. The CTP requires a separate 3.3V power supply (CTP_VDD).
- TN Display with 12 O'clock View Direction: The display uses standard TN technology with the best image quality at and the grayscale inversion occurs at the 12:00 o'clock direction. The viewing angles are limited compared to IPS displays (45°/20°/45°/45°).
- Reset Sequence: The RST pin (Pin 9) is an active-low reset signal. The module must be properly reset after power-up and before any SPI commands are sent.
- TE (Tearing Effect) Pin: The TE pin (Pin 10) is an output from the driver IC that can be used to synchronize the host's frame writes to the display's internal frame memory. This prevents tearing artifacts.
- Temperature Range (-20°C to +70°C Operating): A standard consumer/industrial temperature range. It is suitable for most indoor and outdoor applications.
- Mechanical Integration (Module Outline 49.5mm × 76mm × 3.18mm): The module is relatively thin (3.18mm) including the FPC and touch panel. The outline drawing specifies mechanical features like the active area, LCD/CF edge distances, and recommended foam window dimensions (suggested to be at least 0.3mm smaller than VA on each side to avoid light leakage). The general tolerance is ±0.20mm.
- ESD and Handling: The document specifies ESD handling precautions. The front polarizer is glass, and the rear polarizer is attached. Do not apply excessive force to the display area.
Handling & Compliance
- Observe standard ESD precautions during handling and assembly.
- The module contains fragile glass – handle with care. Avoid mechanical stress on the active area or FPC.
- Do not attempt to disassemble or modify the LCD module.
- The module is RoHS compliant.
- The customer's case foam window must not be larger than the specified opening in the outline drawing to avoid light leakage issues.
5. Conclusion & Design-In Support
The LSC024T35-S-V1 specification details a cost-effective, standard 2.4-inch QVGA (240×320) TN TFT LCD module with an integrated capacitive touch panel (OGS, CST816D), dual-power supply (2.8V/3.3V), and an SPI interface — a suitable choice for embedded applications requiring a simple, reliable touch display with a well-understood interface.
Key Strengths
- Simple SPI Interface: Easy to interface with most microcontrollers with minimal pin count.
- Integrated Capacitive Touch Panel (OGS): Provides a complete touch display solution with enhanced durability and clarity (Transmittance ≥85%, Surface Hardness >6H).
- Cost-Effective TN Display Technology: Suitable for applications where wide viewing angles are not a primary requirement.
- Compact 2.4-inch Form Factor: Suitable for portable and space-constrained designs.
- Detailed Mechanical Drawings and Pinout: Clear mechanical drawings (LCM and CTP+LCM) and pin assignments facilitate straightforward system integration.
Main Design Focus
- The critical design tasks are providing dual power supplies (VDD=2.8V, IOVCC=3.3V) with proper decoupling, implementing a constant-current LED backlight driver (80mA at 3V), configuring the host processor's SPI interface (MOSI, SCLK, A0, CS) with the correct timing (refer to the ST7789P3 datasheet for TBD parameters), and initializing and communicating with the CST816D touch controller over I²C (CTP_SCL, CTP_SDA, CTP_INT, CTP_RST).
- Supporting requirements: Connect all ground pins. Ensure the RST pin can be driven low for a proper reset sequence. Integrate the TE pin for frame synchronization if needed.
This module is a straightforward and cost-effective choice for engineers designing embedded systems that require a simple SPI-based touch display with a durable OGS touch panel.
