Product Main Title:
LS035I12-R-V1: 3.45-Inch TFT LCD Module, 640x480 Resolution, 16.7M Colors, RGB/SPI Dual Interface, for Graphical Display Applications
Product Subtitle / Keywords:
3.45 Inch Display, VGA 640x480 Resolution, Transmissive a-Si TFT, RGB Parallel & 3-Wire SPI Interfaces, COG+FPC+B/L, 16.7M Colors, 450 cd/m² Luminance, -20°C to +70°C Operation, Detailed RGB Timing & Pinout
Comprehensive Technical Specification & Application Guide
1. Executive Summary & Product Positioning
The LS035I12-R-V1, developed by LESSON (Wan'an) Zhixian Technology Co., Ltd., is a versatile 3.45-inch transmissive amorphous Silicon TFT-LCD module. This product specification book serves as the definitive technical document, meticulously defining its structural composition (TFT-LCD panel, driver circuit, backlight unit), mechanical dimensions, absolute maximum ratings, detailed electrical characteristics, and comprehensive interface definitions for both 24-bit RGB parallel and 3-wire serial (SPI) communication. It delivers a VGA resolution of 640(RGB)×480 with 16.7 million color capability and a typical luminance of 450 cd/m². The results demonstrate that the module meets the core technical requirements for graphical display applications in terms of physical, electrical, and photoelectric performance. It is recommended to match and verify system design based on the mechanical, electrical, and optical parameters in this specification to ensure compatibility and stable performance.
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, a driver circuit, and a backlight unit. Includes an optional lens (LCM+LENS dimensions provided).
- Interface Flexibility: Supports dual host interfaces:
- 24-bit RGB Parallel Interface (DE mode or SYNC mode)
- 3-Wire Serial Interface (SPI) for command/initialization (SEKB, SPCK, SPDA)
- Viewing Direction: Specifications indicate wide viewing angles (Typ. 85°).
3. Exhaustive Technical Specifications
3.1 Mechanical & Physical Specifications
- Panel Size (Diagonal): 3.45 inches
- LCM+LENS Module Size (H×V×D): 76.84 mm × 63.84 mm × 3.27 mm
- Active Area (H×V): 70.08 mm × 52.56 mm
- Resolution: 640 (RGB) × 480 pixels
3.2 Optical & Electro-Optical Characteristics (Typical, Ta=25°C)
- Luminance (L): 450 cd/m² (Typical) @ Backlight Forward Current (I_F) = 40mA.
- Contrast Ratio (CR): 600 (Min), 800 (Typ) @ center (θx=θy=0°).
- Response Time (Tr+Tf): 25 ms (Typ), 50 ms (Max).
- Transmittance (T%): 3.7% (Min), 4.4% (Typ).
- Color Chromaticity (White): W x ≈ 0.297, W y ≈ 0.317 (Typical).
- Viewing Angle (CR>10): 75° (Min), 85° (Typ) for all directions.
3.3 Electrical & Interface Specifications
3.3.1 Absolute Maximum Ratings
| Item | Symbol | Min | Max | Unit | Remark |
|---|---|---|---|---|---|
| Supply voltage | VDD | -0.3 | 6.6 | V | |
| Operating temperature | TOPR | -20 | 70 | °C | |
| Storage temperature | TSTR | -30 | 80 | °C |
3.3.2 Electrical Characteristics (DC)
| Item | Symbol | Min | Typ | Max | Unit | Remark |
|---|---|---|---|---|---|---|
| Supply Voltage (Main) | VDD | 2.5 | 2.8 | 3.3 | V | Note1 |
| Input Voltage (L) | VIL | 0 | -- | 0.3*IOVCC | V | Note1 |
| Input Voltage (H) | VIH | 0.7*IOVCC | -- | IOVCC | V | Note1 |
| (IOVCC value is TBD in the provided excerpt) |
3.3.3 Pin Description (54-pin, Excerpt)
The module uses a 54-pin connector supporting both RGB and SPI modes.
| Pin No. | Symbol | I/O | Description |
|---|---|---|---|
| 1-4 | LEDK, LEDA | P | Backlight Cathode/Anode |
| 8 | RESET | I | Reset |
| 9 | SEKB | I | 3-Wire Communication Enable (SPI) |
| 10 | SPCK | I | 3-Wire Communication Clock (SPI) |
| 11 | SPDA | I/O | 3-Wire Communication Data (SPI) |
| 12-35 | DB0-DB23 | I | 24-bit RGB Data Bus (B[0:7], G[0:7], R[0:7]) |
| 36 | HSYNC | I | Horizontal Sync (RGB I/F) |
| 37 | VSYNC | I | Vertical Sync (RGB I/F) |
| 38 | DCLK | I | Pixel Clock (RGB I/F) |
| 52 | DE | I | Data Enable (RGB I/F Mode 1) |
| 41-42, 53-54 | VDD, GND | P | Power & Ground |
3.3.4 Critical Interface Timing
- Reset Timing: Reset low pulse width (
t_RESW) ≥ 10 µs. Reset complete time (t_REST) depends on mode: ≤5 ms (Sleep-in mode) or ≤120 ms (Sleep-out mode). - RGB Interface Timing (DE/SYNC Mode): Provides detailed setup/hold times for VS/HS/DE/Data relative to PCLK (min. 5 ns), and PCLK cycle/period specs (min. 14 ns cycle, 7 ns H/L period). Example timing parameters for a 720x1280 resolution are also given as a reference.
- SPI Timing: Timing parameters for the 3-wire interface are defined, though specific Min/Max values may require consulting the full document.
4. Application Guidelines & Critical Notes
- Intended Use: Industrial instrumentation, portable test equipment, gaming peripherals, automotive aftermarket displays—applications requiring a medium-resolution color display with a fast parallel interface or simple serial control.
- Critical Design Considerations:
- Interface Mode Selection: Determine whether to use the full 24-bit RGB interface (for high-speed graphics) or the 3-wire SPI (for simpler command-based updates). The pinout supports both.
- RGB Timing Generator: If using RGB mode, the host must generate precise HSYNC, VSYNC, DCLK, and DE signals that meet the module's setup/hold and blanking period requirements.
- Power Supply: Provide a stable 2.8V (VDD) supply. The IOVCC level (TBD) will dictate logic thresholds.
- Wide Data Bus: The 24-bit RGB bus requires a significant number of GPIOs or a dedicated graphics controller on the host side.
- Backlight Driver: Design an external constant-current driver for the LED backlight.
5. Conclusion & Design-In Support
The LS035I12-R-V1 specification presents a capable 3.45-inch display with the unique combination of a full 24-bit RGB interface and a 3-wire SPI. This makes it suitable for both high-performance graphical applications and simpler microcontroller-based projects. Its key differentiator is the VGA (640x480) resolution on a 3.45-inch diagonal, offering higher pixel density. Successful integration requires the host system to have sufficient resources to drive the wide parallel bus and generate compliant video timing, or to utilize the SPI interface effectively. Careful consultation of the complete timing parameters is essential for reliable operation.
