LSR024T17-S-V2 | 2.4 inch TFT-LCD Module | 240x320 | SPI | TN | 262K Colors
1. Executive Summary & Product Positioning
The LSR024T17-S-V2 is a 2.4-inch color a-Si TFT-LCD module developed by 立信(万安)智显科技有限公司 (Lesson Smart Display Technology Co., Ltd). It features a QVGA (240×320) resolution and supports 262,144 colors. The module integrates a 4-wire resistive touch panel (RTP) and uses an SPI interface for communication. Its compact size and embedded touch solution make it ideal for various handheld and embedded applications.
Product Positioning: This module is designed for applications requiring a small to medium-sized color display with touch input. Typical uses include smart home devices, industrial handheld terminals, medical equipment user interfaces, portable instruments, and other human-machine interface (HMI) systems where cost-effectiveness and ease of integration are key.
2. Detailed Product Overview & Architecture
The module comprises a TFT-LCD panel, a driver circuit, a backlight unit, and an integrated 4-wire resistive touch panel. Key components and features include:
- TFT-LCD Panel: 2.4-inch diagonal, a-Si TFT active matrix, transmissive, TN (Twisted Nematic) mode. Resolution is 240(H) × 320(V) pixels.
- Color Depth & Interface: Supports 262K colors via a 4-wire Serial Peripheral Interface (SPI).
- Driver IC: The module is driven by the ST7789T3 IC.
- Touch Panel: Includes a 4-wire Resistive Touch Panel (RTP) with dedicated control pins (XL, YU, XR, YD) on the FPC.
- Backlight Unit (B/L): An LED backlight with a typical forward current of 80mA and a forward voltage of 2.9V to 3.4V. The typical luminance is 350 cd/m².
- Module Type: COG (Chip on Glass) + FPC + B/L + RTP.
3. Exhaustive Technical Specifications
3.1 General & Mechanical Specifications
| Item | Specification |
| Display Size (Diagonal) | 2.4 inches |
| Resolution (Pixels) | 240 (RGB) × 320 (QVGA) |
| Module Size (H×V×D) | 42.72 × 60.26 × 3.55 mm |
| Active Area (H×V) | 36.72 × 48.96 mm |
| Pixel Pitch | 0.153 (H) × 0.153 (V) mm |
| Display Mode | Transmissive, Normally White, TN (Grayscale Inversion) |
| Number of Dots | 240(RGB) × 320 |
| Input Data Interface | SPI (4-line serial) |
| Driver IC | ST7789T3 |
| Touch Panel | 4-Wire Resistive Touch Panel (RTP) |
| Backlight LEDs | White LED, FORE series and ONE parallel |
3.2 Electrical Characteristics
3.2.1 Absolute Maximum Ratings
| Parameter | Symbol | Min | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | VCC | -0.3 | 4.6 | V |
| Supply Voltage (IOVCC) | IOVCC | -0.3 | 4.6 | V |
| Operating Temperature | TOPR | -20 | 70 | °C |
| Storage Temperature | TSTR | -30 | 80 | °C |
3.2.2 Recommended Operating Conditions
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage | VCC | 2.4 | 2.75 | 3.3 | V |
| I/O Supply Voltage | IOVCC | 1.65 | 1.8 | 3.3 | V |
| Input High Voltage | VIH | 0.7*IOVCC | - | IOVCC | V |
| Input Low Voltage | VIL | 0 | - | 0.3*IOVCC | V |
| Backlight Forward Current (IF) | IF | - | 80 | - | mA |
| Backlight Forward Voltage (Vf) | Vf | 2.9 | - | 3.4 | V |
3.3 Optical Characteristics (Ta=25°C)
| Item | Symbol | Condition | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| Response Time (Tr+Tf) | Tr+Tf | θx = θy = 0° | - | 30 | - | ms |
| Contrast Ratio | CR | θx = θy = 0° | - | 250 | - | - |
| Luminance (IF=80mA) | L | θx = θy = 0° | - | 350 | - | cd/m² |
| Viewing Angle (CR>10) | θT / θB | - | 45 / 20 | - | Deg. | |
| Viewing Angle (CR>10) | θL / θR | - | 45 / 45 | - | Deg. | |
| White Chromaticity (CIE 1931) | Wx / Wy | θx = θy = 0° | - | (0.308, 0.325) | - | - |
3.4 Interface Pin Assignment (18-Pin FPC)
| Pin # | Symbol | I/O | Description |
|---|---|---|---|
| 1 | GND | P | Ground |
| 2 | RESET | I | LCM Reset pin, active low |
| 3 | SCL | I | Serial clock pin |
| 4 | RS (D/CX) | I | Command and Data select pin |
| 5 | CS | I | Chip select pin |
| 6 | SDA (DIN) | I | Serial data input |
| 7 | SDO | O | SPI interface output pin |
| 8 | GND | P | Ground |
| 9 | VDD | P | Power supply for LCM |
| 10 | A (LED+) | P | Anode of Backlight |
| 11-14 | K | P | Cathode of Backlight |
| 15 | XL | I | Touch panel control pin |
| 16 | YU | I | Touch panel control pin |
| 17 | XR | I | Touch panel control pin |
| 18 | YD | I | Touch panel control pin |
4. Application Guidelines & Critical Notes
- Power Supply: Connect VDD (Pin 9) to a supply between 2.4V and 3.3V. The I/O supply (IOVCC) should be between 1.65V and 3.3V. The backlight (Pins 10-14) requires a constant current of 80mA.
- SPI Interface: The module uses a 4-wire SPI interface (SCL, SDA, RS/D/CX, CS). The SDO pin allows for data read-back from the driver IC. Ensure your microcontroller's SPI peripheral is configured correctly, including timing parameters such as serial clock cycle and data setup/hold times.
- Touch Panel (RTP): The 4-wire resistive touch pins (XL, YU, XR, YD) are connected directly to a touch controller on your main board. The touch panel does not have a dedicated controller IC; it provides the raw analog voltages from the resistive sheet.
- Mechanical Integration: The outline drawing provides key dimensions. Note the following recommendations from the manufacturer:
- The housing viewing area should be smaller than the LCM VA (Viewing Area) by at least 0.3mm per side.
- The foam opening on the chassis should be larger than the LCM VA by at least 0.6mm per side.
- The edge of the touch panel (TP) must not contact any metal conductor.
- Backlight: The circuit shows a FORE series and ONE parallel configuration, driven at 80mA. The LED forward voltage (Vf) ranges from 2.9V to 3.4V.
5. Conclusion
The LSR024T17-S-V2 from Lesson Smart Display Technology is a compact, fully-integrated 2.4-inch TFT-LCD module with a resistive touch panel. Its SPI interface and 4-wire analog resistive touch make it easy to integrate with low-pin-count microcontrollers. With good brightness (350 cd/m²) and reasonable contrast (250:1), it is well-suited for a wide range of cost-sensitive embedded applications.
For successful design-in, engineers should pay close attention to the SPI timing characteristics provided in the datasheet, design an appropriate 80mA constant current backlight driver, and include an ADC-equipped interface on the main board to read the 4-wire resistive touch data.
