Product Main Title:
LS0154I05-S-V2: 1.54-Inch IPS TFT LCD Module, 240x240 Resolution, 262K Colors, 4-Line SPI Interface
Product Subtitle / Keywords:
1.54 Inch Display, Square 240x240 Resolution, Transmissive a-Si IPS TFT, 4-line SPI Interface, COG+FPC+B/L, 262K Colors, Wide Viewing Angle, 3-Chip White LED Parallel Backlight, ST7789P3 Driver
Comprehensive Technical Specification & Application Guide
1. Executive Summary & Product Positioning
The LS0154I05-S-V2, developed by LESSON (Wan'an) Zhixian Technology Co., Ltd., is a 1.54-inch transmissive amorphous Silicon TFT-LCD module featuring IPS (In-Plane Switching) technology. This product specification book (Revision 1.0) serves as the definitive technical document, detailing its structural composition (COG+FPC+B/L), precise mechanical dimensions, absolute maximum ratings, detailed electrical characteristics, 4-line SPI (Serial Peripheral Interface) pinout and timing, and comprehensive electro-optical performance definitions. It delivers a square resolution of 240(RGB)×240 with 262K-color display capability, driven by the ST7789P3 controller. The document provides a complete set of technical indicators and design notes. The unequivocal recommendation for manufacturers and users is to strictly adhere to this specification for module selection, assembly, and reliability verification to ensure compliance with RoHS and optical performance requirements.
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).
- Drive IC: ST7789P3.
- Backlight: 3 Chip-White LEDs in parallel.
- Approval Status: Approved Product Specification only.
3. Exhaustive Technical Specifications
3.1 Mechanical & Physical Specifications
| Item | Specification | Unit |
|---|---|---|
| Module size (H×V×D) | 31.52 × 33.72 × 2.04 | mm |
| Active area (H×V) | 27.72 × 27.72 | mm |
| Number of dots / Resolution | 240(RGB) × 240 | pixel |
| Panel Size (Diagonal) | 1.54 | 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: 3 Chip-White LED Parallel.
- 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 | 4.6 | V | Note1, Note2 |
| Operating temperature | TOPR | -20 | 70 | °C | Note1, Note2 |
| Storage temperature | TSTR | -30 | 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 | 2.8 | 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 (15-pin FPC)
| PIN NO. | Symbol | I/O | Description |
|---|---|---|---|
| 1 | CS | I | Chip selection pin. |
| 2 | GND | P | Ground. |
| 3 | SCLK | I | Serial clock pin. |
| 4 | RST | I | This signal will reset the device and it must be applied to properly initialize the chip. |
| 5 | SDA | I | SPI interface input pin. |
| 6 | TE | O | Tearing effect signal is used to synchronize MCU to frame memory. |
| 7 | DCX | I | Display data/command selection pin in 4-line serial interface. |
| 8 | IOVCC | P | I/O power supply. |
| 9 | VCC | P | Main power supply. |
| 10 | VCC | P | Main power supply. |
| 11 | GND | P | Ground. |
| 12 | GND | P | Ground. |
| 13 | LEDA | P | Power for LED backlight anode. |
| 14 | LEDA | P | Power for LED backlight anode. |
| 15 | 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.
A. Write Operation Timing:
| 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_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 |
B. Read Operation Timing:
| Signal | Symbol | Parameter | MIN | MAX | Unit | Description |
|---|---|---|---|---|---|---|
| CSX | T_CSS | Chip select setup time (read) | TBD | - | ns | |
| CSX | T_SCC | Chip select hold time (read) | TBD | - | ns | |
| SCL | T_SCYCR | Serial clock cycle (Read) | TBD | - | ns | For read command & data RAM |
| SCL | T_SHR | SCL "H" pulse width (Read) | TBD | - | ns | For read command & data RAM |
| SCL | T_SLR | SCL "L" pulse width (Read) | TBD | - | ns | For read command & data RAM |
| D/CX | T_DCS | D/CX setup time | TBD | - | ns | |
| D/CX | T_DCH | D/CX hold time | TBD | - | ns | |
| SDA (DIN) | T_SDS | Data setup time | TBD | - | ns | |
| SDA (DIN) | T_SDH | Data hold time | TBD | - | ns | |
| DOUT | T_ACC | Access time | TBD | TBD | ns | For CL=30pF(max)/8pF(min) |
| DOUT | T_OH | Output disable time | TBD | TBD | ns | For CL=30pF(max)/8pF(min) |
(Note: All timing parameters are listed as "TBD" (To Be Determined) in the provided revision. The final production specification or a later revision would define concrete values.)
3.2.5 Backlight Unit
- Configuration: 3 Chip-White LEDs in parallel.
- Drive Condition (Typical): Forward Current (I_F) = 60 mA; Forward Voltage (V_f) = 3 V.
3.3 Optical & Electro-Optical Characteristics
(Note: Specific optical tables (Luminance, Contrast, Viewing Angle, etc.) for this model are part of Section 8 but are not provided in the given context excerpt. The definitions for response time, contrast ratio, and viewing angle measurement are provided.)
Optical Measurement Definitions:
- Response Time: Defined as the interval between 10% and 90% of amplitude when switching between "White" and "Black" states.
- Contrast Ratio (CR): Calculated as (Brightness on the "white" state) / (Brightness on the "black" state).
- Viewing Angle: Defined with 0° at the 12 o'clock direction. Optical characteristics are measured using instruments like the Topcon BM-5A luminance meter and Otsuka LCF-2100M chromaticity meter.
4. Application Guidelines & Critical Notes
- Intended Use: Wearables, compact IoT devices, handheld instruments, auxiliary displays—applications requiring a small, square, 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 0.3mm smaller per side than AA; foam cutout should be 0.6mm larger per side 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 (Pin 6) can be used to synchronize graphics updates with the panel's refresh cycle, reducing tearing artifacts.
- Backlight Drive: The backlight uses 3 LEDs in parallel, requiring a ~3V drive voltage at 60mA total. Design a suitable constant-current driver.
- Reset Circuit: Ensure the RST pin (Pin 4) receives a proper low pulse during initialization to correctly reset the ST7789P3 driver IC.
- Temperature Ranges: Operate within -20°C to +70°C and store within -30°C to +80°C.
- Handling & Compliance: The module is ROHS compliant. Observe standard ESD precautions during handling and assembly.
5. Conclusion & Design-In Support
The LS0154I05-S-V2 specification details a compact 1.54-inch square IPS SPI display module. Its key strengths are the square aspect ratio ideal for icons and symmetric UIs, wide viewing angles from IPS technology, and a standard 4-line SPI interface controlled by the common ST7789P3 driver. The main design focus should be on precise mechanical housing design, providing the dual power supplies, and implementing the 60mA LED driver for the parallel backlight. While the AC timing parameters are TBD in the provided revision, the core electrical, mechanical, and functional specs provide a solid foundation for integration into space-constrained, battery-powered devices.
