Product Subtitle / Keywords:
1.44 Inch Display, 128(RGB)×128 Resolution, Transmissive a-Si TN TFT, SPI Serial Interface, COG+FPC+B/L, 262K Colors, ST7735S Driver, 2.1mm Thickness, 260 cd/m² Brightness, 600:1 Contrast Ratio, -20°C~70°C Operating Temperature
1. Executive Summary & Product Positioning
The **LS0144T04-S-V1
The LS0144T04-S-V1, developed by Lixin (Wan'an) Intelligent Display Technology Co., Ltd. (立信(万安)智显科技有限公司), is a 1.44-inch transmissive amorphous Silicon TFT-LCD module with TN (Twisted Nematic) technology.
This product specification (Revision 1.0, Module Type: COG+FPC+B/L) serves as the definitive technical document, defining its structural composition (COG+FPC+B/L), physical features, mechanical dimensions, absolute maximum ratings, detailed electrical characteristics, complete interface pinout and timing, and comprehensive electro-optical performance. It delivers a QQVGA resolution of 128(RGB)×128 with 262K-color display capability, driven by the ST7735S controller.
The document provides the core parameters necessary for system integration into compact embedded display applications. The unequivocal recommendation for engineers is to strictly adhere to the electrical specifications, interface timing, and mechanical tolerances 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).
- Display Mode: Active matrix TFT, Transmissive type, TN.
- 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.
- Input Data: SPI (Serial Peripheral Interface).
- Viewing Direction (Grayscale Inversion): 12 o'clock (as per mechanical drawing notes).
- Drive IC: ST7735S.
- Approval Status: ☑ Approved Product Specification only (as per signature block).
3. Exhaustive Technical Specifications
3.1 Mechanical & Physical Specifications
| Item | Specification | Unit |
|---|---|---|
| Module size (H×V×D) | 27.9 × 32.64 × 2.1 | mm |
| Active area (H×V) | 25.5 × 26.5 | mm |
| Number of dots / Resolution | 128(RGB) × 128 | pixel |
| Panel Size (Diagonal) | 1.44 | inch |
Critical Mechanical Design Notes (from document):
- Display Type: Main LCD: Transmissive, TN.
- Operating Temperature: -20°C ~ +70°C.
- Storage Temperature: -30°C ~ +80°C.
- Main LCD Driver: ST7735S.
- Backlight: 2 Chip-White LED, Parallel.
- General Tolerance: ±0.20 mm (Segments to edge of glass).
- Bezel Opening Design: It is recommended that the housing's visible area be at least 0.3mm smaller per side than the module's viewing area (VAmds).
- Foam Gasket Cutout Design: The cutout in the chassis foam gasket should be at least 0.6mm larger per side larger than the module's viewing area (VAmds).
- TP/Conductor Isolation: The Touch Panel (TP) edges must not come into contact with any metal conductors.
- ROHS Compliance: Yes.
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 |
| 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 – Recommended Operating Conditions)
| Item | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply voltage for logic | IOVCC | 1.65 | 1.8 | 3.3 | V |
| Supply voltage for analog | VCI | 2.5 | 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 (from mechanical drawing)
The mechanical drawing provides the following pin assignments for the 15-pin interface:
| PIN NO. | Symbol | Description |
|---|---|---|
| 1 | LEDK | Backlight LED Cathode pin. |
| 2 | GND | Ground. |
| 3 | FMARK | Tearing effect signal is used to synchronize MCU to frame memory writing. |
| 4 | SDA | Serial input/output data. |
| 5 | RS | Data/command selection pin in 4-line serial interface. |
| 6 | SCL | Clock signal. |
| 7 | CS | Chip selection signal. |
| 8 | RESET | This signal will reset the device and it must be applied to properly initialize the chip. |
| 9 | IOVCC1.8 | Power supply for interface logic circuits (1.65~3.3V). |
| 10 | VCC2.8 | Power supply for analog circuit blocks (2.6~3.3V). |
| 11 | VCC2.8 | Power supply for analog circuit blocks (2.6~3.3V). |
| 12 | GND | Ground. |
| 13 | GND | Ground. |
| 14 | LEDA | Backlight LED Anode pin. |
| 15 | LEDA | Backlight LED Anode pin. |
Interface Summary:
- SPI Interface: Uses SCL (Serial Clock), SDA (Serial Data), RS (Data/Command), RESET, and CS (Chip Select) for communication.
- Backlight: Dedicated LEDA (Anode, Pins 14, 15) and LEDK (Cathode, Pin 1) pins.
- Power: IOVCC1.8 (Pin 9) for I/O logic, VCC2.8 (Pins 10, 11) for analog circuits, GND (Pins 2, 12, 13) for ground.
3.2.4 Interface Timing Characteristics (4-line Serial Interface)
| Signal | Symbol | Parameter | Min. | Max. | Unit | Description |
|---|---|---|---|---|---|---|
| CSX | tcss | Chip select setup time (Write) | 15 | — | ns | |
| CSX | tcsh | Chip select setup time (Write) | 15 | — | ns | |
| CSX | tcss | Chip select hold time (Read) | 60 | — | ns | |
| CSX | tcsh | Chip select hold time (Read) | 65 | — | ns | |
| DCX | tas | Address setup time | 10 | — | ns | |
| DCX | tah | Address hold time (Write/Read) | 10 | — | ns | |
| SCL (write) | twc | Write cycle | 16 | — | ns | |
| SCL (write) | twrh | Control pulse "H" duration | 7 | — | ns | |
| SCL (write) | twrl | Control pulse "L" duration | 7 | — | ns | |
| SCL (read) | trc | Read cycle | 150 | — | ns | |
| SCL (read) | trdh | Control pulse "H" duration | 60 | — | ns | |
| SCL (read) | trdl | Control pulse "L" duration | 60 | — | ns | |
| SDI/SDO (write) | tds | Data setup time | 7 | — | ns | |
| SDI/SDO (write) | tdt | Data hold time | 7 | — | ns | |
| SDI/SDO (read) | tracc | Read access time | — | 50 | ns | |
| SDI/SDO (read) | tod | Output disable time | 15 | 50 | ns |
3.2.5 Power On/Off Sequence
The document specifies two power-on sequence options for the internal DC/DC power mode (IOVCC=VCCH=1.65V ~ 3.3V, VCI=VCIP=2.6V ~ 3.3V):
Option 1: Host sends initial setting, then SLPOUT and DISP ON.
- Power up IOVCC (1.65V ~ 3.3V).
- Power up VCI (2.6V ~ 3.3V) with a ramp time ( ) of 0.2ms to 20ms.
- Wait for >= 10ms.
- Apply HW Reset with a pulse width ( ) of 10μs.
- Wait 5ms.
- Send Initial Setting commands.
- Send SLPOUT (0x11) command.
- Wait 120ms.
- Send DISP ON (0x29) command.
Option 2: Host only sends SLPOUT and DISP ON.
- Power up IOVCC (1.65V ~ 3.3V).
- Power up VCI (2.6V ~ 3.3V) with a ramp time ( ) of 0.2ms to 20ms.
- Wait for >= 10ms.
- Apply HW Reset with a pulse width ( ) of 10μs.
- Wait 5ms.
- Send SLPOUT (0x11) command.
- Wait 120ms.
- Send DISP ON (0x29) command.
Key Timing Observation:
- The power-up ramp time for VCI/IOVCC is between 0.2ms and 20ms.
- After hardware reset, a 5ms wait is required before sending commands.
- After SLPOUT command, a 120ms wait is required before sending DISP ON.
3.2.6 Backlight Unit
| Item | Specification | Unit |
|---|---|---|
| LED Circuit | 2 Chip-White LED, Parallel | — |
| Drive Condition | IF = 40mA, Vf = 3.2V (Typ) | — |
3.3 Optical & Electro-Optical Characteristics (Ta=25°C)
| Item | Symbol | Condition | Min. | Typ. | Max. | Unit | Remark |
|---|---|---|---|---|---|---|---|
| Viewing Angle (3:00) | CR≥10 | — | 60 | — | ° | Note1 | |
| Viewing Angle (6:00) | CR≥10 | — | 60 | — | ° | Note1 | |
| Viewing Angle (9:00) | CR≥10 | — | 60 | — | ° | Note1 | |
| Viewing Angle (12:00) | CR≥10 | — | 60 | — | ° | Note1 | |
| Response Time | Ton+Toff | — | — | 32 | ms | Note2 | |
| Contrast Ratio | CR | 400 | 600 | — | — | Note3 | |
| Luminance | L | 220 | 260 | — | cd/m² | Note4 | |
| White Chromaticity | Normal | -0.03 | TBD | +0.03 | — | Note5 | |
| White Chromaticity | Normal | -0.03 | TBD | +0.03 | — | Note5 | |
| NTSC Color Saturation | % | 45 | 50 | — | % |
Notes (from document):
- Viewing Angle: Determined for the horizontal (3, 9 o'clock) and vertical (6, 12 o'clock) directions. The module has 60° (Typ) viewing angles in all directions.
- Response Time: Ambient temperature = 25°C. Response time is the time required for the display to transition from white to black (Rising time, Tr) and from black to white (Falling time, Tf).
- Contrast Ratio (CR): Measured at the center of the LCD surface. CR = Luminance (white raster) / Luminance (black raster).
- Luminance: Measured at the center point across the LCD surface 500mm from the surface with all pixels displaying white.
- Color Chromaticity: Measured with C light source.
3.4 Reliability Specification
| No | Items | Conditions | Remark |
|---|---|---|---|
| 1 | High Temperature Storage test (HTS) | 70°C, 48hrs, Non-operational | Note 1, Note 4 |
| 2 | Low Temperature Storage test (LTS) | -20°C, 48hrs, Non-operational | Note 1, Note 4 |
| 3 | High Temperature Operating test (HTO) | 60°C, 24hrs, operational | Note 1, Note 4 |
| 4 | Low Temperature Operating test (LTO) | -10°C, 24hrs, operational | Note 1, Note 4 |
| 5 | Thermal Humidity Operating test (THO) | 50°C/90%RH, 24hrs, operational | Note 4 |
| 6 | Thermal Cycle Storage test (TST) | -0°C/30 min~+50°C/30 min for a total 100 cycles, Start with cold temperature and end with high temperature. | Note 4 |
| 7 | Vibration Test | Frequency range:10~55Hz Stroke:1.5mm Sweep:10Hz~55Hz~10Hz 2 hours for each direction of X. Y. Z.(6 hours for total) | |
| 8 | Electro Static Discharge | ±2KV, Human Body Mode, 100pF/1500Ω |
Note 1: Ta is the ambient temperature of samples.
Note 4: Before cosmetic and function test, the product must have enough recovery time, at least 2 hours at room temperature.
4. Application Guidelines & Critical Notes
Intended Use
- Low-cost IoT devices
- Simple user interfaces requiring compact size
- Applications where resolution requirements are modest (128x128)
- Wearable devices, smart home controls, miniature instruments
Critical Design Considerations
-
Interface (SPI): This module uses an SPI (Serial Peripheral Interface) for communication. The host MCU must have at least 5 GPIOs (SCL, SDA, RS, RESET, CS) to drive the display.
-
Power Supply:
- Provide stable VCC2.8 (2.8V typical) for the analog circuits.
- Provide stable IOVCC1.8 (1.8V typical) for the I/O interface.
- The backlight requires a constant-current LED driver set to 40 mA at 3.2V (Typ).
-
Power-On Sequence: Strictly follow the power-on sequence described in Section 3.2.5 to ensure proper initialization. The sequence requires:
- Power up IOVCC and VCI with a ramp time of 0.2ms to 20ms.
- Wait for >= 10ms.
- Apply hardware reset with a pulse width of 10μs.
- Wait 5ms before sending commands.
- Send SLPOUT command and wait 120ms before sending DISP ON.
-
Mechanical Integration:
- Module Outline: 27.9mm (H) × 32.64mm (V) × 2.1mm (D).
- Active Area: 25.5mm × 26.5mm.
- Bezel Opening: Design the housing window 0.3mm smaller per side than the viewing area.
- Foam Gasket: Design the cutout 0.6mm larger per side than the viewing area.
- FPC: The module uses a 15-pin FPC. The exact pitch is not specified in the excerpt, but should be verified from the mechanical drawing.
-
Reset Timing: The reset pulse must be at least 10 μs wide. The reset complete time is 5 ms or 120 ms, depending on the specific condition.
-
Temperature Limits:
- Operating Temperature: -20°C to +70°C.
- Storage Temperature: -30°C to +80°C.
Handling & Compliance
- The module is ROHS compliant.
- Observe standard ESD precautions during handling and assembly.
- The module contains fragile glass and a 15-pin FPC – handle with care.
- The module is 2.1mm thick – be careful when handling to avoid flexing.
5. Conclusion & Design-In Support
The LS0144T04-S-V1 specification details a compact 1.44-inch TN display module with an SPI interface — an excellent choice for cost-sensitive, simple display applications.
Key Strengths:
- Compact Size: 27.9mm × 32.64mm — one of the smallest modules in the product line.
- Square Resolution (128x128): Suitable for simple icons, text, and basic UIs.
- Standard SPI Interface: Requires only 5 GPIOs for communication, simplifying integration.
- Clear Power-On Sequence: The document provides explicit power-on sequence options for reliable initialization.
- Adequate Brightness: 260 cd/m² (Typ) brightness ensures readability in indoor readability.
- Good Contrast Ratio: 600:1 (Typ) provides decent image quality for a TN panel.
Main Design Focus:
- The critical design task is following the power-on sequence and ensuring proper reset timing.
- Supporting requirements:
- Provide stable VCC2.8 (2.8V typical) and IOVCC1.8 (1.8V typical) power.
- Provide a constant-current backlight driver set to 40 mA at 3.2V (Typ).
- Mechanical integration — follow the bezel opening and foam cutout guidelines.
- FPC connector — verify the 15-pin FPC pitch from the mechanical drawing.
This module is an excellent choice for designs where cost, size, and simplicity are the primary concerns, such as simple numeric displays, status indicators, or low-cost IoT nodes.