LS0395I17-R-V1: 3.95-Inch Square TFT LCD Module, 480x480 Resolution, 16.7M Colors, Hybrid 3WSPI+RGB18BIT Interface, ST7701S Driver, for Flexible Embedded System Integration

Product Subtitle / Keywords:
3.95 Inch Square Display, 480x480 Resolution, Transmissive a-Si TFT, ST7701S Driver IC, Dual Interface (3-Wire SPI & 18-bit RGB), COG Structure, 400 cd/m² Luminance, All-Direction Viewing, -20°C to +70°C Operation, Detailed Serial & RGB Timing, Reliability Test Conditions, Visual Inspection Criteria

Comprehensive Technical Specification & Application Guide

1. Executive Summary & Product Positioning
The LS0395I17-R-V1 is a flexible 3.95-inch square transmissive a-Si TFT-LCD module from LESSON Smart Display Technology Co., Ltd. This product specification book provides a complete technical definition, detailing its structure, resolution and color capabilities, absolute electrical limits, and precise timing characteristics for its unique hybrid 3WSPI+RGB18BIT data interface. The module delivers 480×480 pixel resolution with 16.7 million color display capability, operating from -20°C to +70°C. The specification provides exhaustive electrical parameters, interface timing tables for both SPI and RGB modes, and clear environmental reliability test conditions. The results confirm the module meets multiple environmental and lifespan test requirements and defines clear defect判定准则 (criteria) and protection suggestions. The explicit and strong recommendation for production and usage is to strictly follow the electrical limits, environmental restrictions, and inspection criteria within this specification. This is the fundamental requirement to guarantee the module's performance, reliability, and consistent quality in the target application.

2. Detailed Product Overview & Architecture

• Core Technology: Transmissive-type a-Si TFT-LCD.
• Display Characteristics: Capable of displaying up to 16.7 million colors.
• Module Construction: Composed of a TFT-LCD panel, driver IC (ST7701S), FPC, and a backlight unit (BLU).
• Interface Flexibility: Features a dual data interface controlled by the ST7701S driver:
  • 3-Wire SPI (3WSPI): For command and low-speed data transfer.
  • 18-bit RGB Parallel Interface (RGB18BIT): For high-speed pixel data transfer.
    This architecture allows efficient control via SPI while leveraging RGB for fast display updates.

3. Exhaustive Technical Specifications
3.1 Mechanical & Physical Specifications

• LCM Outline Size (H×V): 74.66 mm × 76.54 mm
• Active Area (H×V): 71.86 mm × 69.51 mm
• Number of Pixels: 480(H) × 480(V)
• Pixel Arrangement: RGB Stripe
• Pixel Pitch: 0.1497 mm (H) × 0.1462 mm (V)
• Viewing Direction: ALL (as per general info)
• Controller / Driver: ST7701S
• Backlight: 10 White LEDs in Parallel

3.2 Electrical & Interface Specifications
3.2.1 Absolute Maximum Ratings (Ta=25±2°C, Vss=GND=0V)

• I/O Supply (IOVCC): -0.3V to +3.6V
• Analog Supply (VCI): -0.3V to +3.6V
• TFT Gate Voltages (VGH/VGL): -0.3V to +30V
• Backlight Forward Current (IF): 40 mA (Max)
• Operating Temperature (TOPR): -20°C to +70°C (Note: Below 0°C, LC response slows and screen darkens)
• Storage Temperature (STG): -30°C to +80°C (Note: Extended high temp may damage polarizer)

3.2.2 Electrical Characteristics (DC, Ta=25±2°C)

• Power Supply 1 (IOVCC): 1.65V to 3.3V (Typ. 1.8V)
• Power Supply 2 (VCI): 2.5V to 3.6V (Typ. 2.8V)
• Logic Levels (referenced to IOVCC):
  • VIL: GND to 0.3*IOVCC
  • VIH: 0.7*IOVCC to IOVCC
  • VOL (Max @ IOL=+1.0mA): 0.2*IOVCC
  • VOH (Min @ IOH=-1.0mA): 0.8*IOVCC
• Current Consumption: Normal mode (IDD) and Sleep mode (IDD-SLEEP) are TBD.

3.2.3 Backlight Unit Characteristics (Ta=25±2°C)

• Forward Voltage (Vf): 15V (Typical) @ IL=40mA
• Forward Current (IL): 40 mA (Typical)
• Luminance (Lv): 400 cd/m² (Typical) @ IL=40mA
• LED Lifetime: 20,000 hrs (Min), 25,000 hrs (Typ) @ IL=40mA

3.3 Optical Characteristics (Ta=25±2°C, Typical)

• Contrast Ratio (Center): 400 (Typical)
• Luminance of White (Center, Lw): TBD (To Be Determined)
• Luminance Uniformity (Uw): ≥ 80%
• Response Time (Tr+Tf): 25 ms (Typ), 35 ms (Max)
• Viewing Angle (CR≥10): 80° (Typical) for all directions (Top, Bottom, Left, Right).
• Chromaticity Coordinates (Typical):
  • White: Wx≈0.302, Wy≈0.325
  • Red: Rx≈0.624, Ry≈0.329
  • Green: Gx≈0.288, Gy≈0.522
  • Blue: Bx≈0.136, By≈0.137

3.4 Interface Description & Critical Timing
3.4.1 Pin Description (Example from 13-pin list)
Pins include: LEDA, LEDK(x2), GND, VCC (2.8-3.3V for I/O), RST, NC(x2), SDA, SCL, CS, PCLK, DE.
3.4.2 3-Line Serial Interface (SPI) Timing Characteristics
Detailed parameters under VDDI=1.8V, VDD=2.8V, Ta=25°C:

• Chip Select: Setup/Hold/Pulse width (TCSS, TCSH, TCHW).
• Serial Clock (SCL): Cycle time and H/L pulse widths for Write (TSCYW, TSHW, TSLW) and Read (TSCYCR, TSHR, TSLR) operations.
• Serial Data (SDA): Setup/Hold time (TSDS, TSDH).
• Signal Rise/Fall Time (Tr, Tf): Specified as 15 ns or less.

3.4.3 RGB Interface Timing Characteristics
Detailed parameters under same conditions:

• Sync & Enable: VSYNC/HSYNC setup (TSYNC), ENABLE setup/hold (TENS, TENH).
• Dot Clock (PCLK): High/Low pulse width (PWDH, PWDL), cycle time (TCYCD), rise/fall time (Trghr, Trghf ≤15ns).
• Data Bus (DB): Setup/Hold time (TPDS, TPDH).

4. Reliability & Quality Inspection
4.1 Reliability Test Conditions
A defined set of tests with clear pass/fail inspection criteria after 2-4 hours recovery at room temperature. Defects not allowed include:

1. Air bubble in the LCD
2. Seal leak
3. Non-display
4. Missing segments
5. Glass crack
6. Surface damage
7. Electrical characteristics out of spec.

• Test Items: High/Low Temperature Storage (+80°C/-30°C, 240H), Temperature Cycle (-10°C↔+50°C, 10 cycles), High Temp/Humidity Storage (60°C, 90%RH, 240H), ESD test (Open Cell, Air mode, +2KV).

4.2 Inspection Criterion
Provides detailed visual defect判定准则 (judgment standards) in tables:

• Pixel Defects: Classifies Bright Spots and Dark/Black Spots by size (Φ), with allowable quantities (N) per zone (A/B).
• FPC Defects: Specifies criteria for component soldering (no cold solder, short/open; position deviation), lead defects (lack, burr), and connector soldering (no solder in contact area, no burnt base, no serious pin distortion).

5. Application Guidelines & Critical Notes

• Intended Use: Embedded systems requiring display control flexibility, portable devices, industrial controls where both command interface and display performance are important.
• Critical Design Considerations:
  • Interface Selection: Understand how to utilize the dual-interface capability. Typically, SPI is used for initialization and command control, while RGB is used for frame buffer updates.
  • Timing Compliance: Ensure the host microcontroller or processor can generate signals meeting the detailed SPI and RGB timing parameters provided.
  • Power Sequencing: Ensure supplies (VCI, IOVCC) are stable before releasing reset.
  • Backlight Current: Do not exceed the maximum 40mA forward current.
• Handling & Assembly Precautions (from doc):
  • ESD: Operate in an ESD-protected environment.
  • Soldering: Use properly grounded soldering irons. For RoHS products: temp 340-370°C, time 3-5s.
  • Cleaning: Remove flux residue after soldering (unless non-halogen type).
  • Direct Contact: Do not touch CMOS LSI pads or interface terminals with bare hands.

6. Conclusion & Design-In Support
The LS0395I17-R-V1 specification provides a robust foundation for integrating a versatile square display. Its key strength lies in the detailed timing specifications for both serial and parallel interfaces, giving designers the precise information needed for reliable communication. Success requires careful attention to the absolute maximum ratings (especially temperature effects on LC response) and adherence to the provided soldering and handling guidelines to prevent manufacturing defects. By leveraging the hybrid interface efficiently and following all electrical and environmental limits, designers can fully utilize this module to create embedded systems with capable and reliable display functionality.