Product Subtitle / Keywords:
1.77 Inch Display, 128(RGB)×160 Resolution, Transmissive a-Si TFT-LCD, 4-Line Serial Interface, COG+FPC+B/L, 262K Colors, ST7735V3 Driver, 34.7×46.7×2.5 mm, 300:1 Contrast Ratio, 6.8% Transmittance, 45°/20°/45°/45° Viewing Angle, -20°C~70°C Operating Temperature

1. Executive Summary & Product Positioning

The LS0177T02-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 1.77-inch transmissive amorphous Silicon TFT-LCD (a-Si TFT-LCD) module.

This product specification (Revision 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 4-line Serial Interface pinout and timing, and comprehensive electro-optical performance. It delivers a resolution of 128(RGB)×160 with 262K-color display capability, driven by the ST7735V3 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.
• Display Format: Graphic 128(RGB)×160 Dot-matrix.
• 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: 4-line serial interface.
• Viewing Direction (Grayscale Inversion): TN.
• Drive IC: ST7735V3.
• Approval Status: ☑ Approved Product Specification only (as per signature block).

3. Exhaustive Technical Specifications

3.1 Mechanical & Physical Specifications

Critical Mechanical Design Notes (from document):

1. Display Type: Main LCD: 262K TFT TRANSMISSIVE 6:00.
2. Operating Temperature: -20°C ~ +70°C.
3. Storage Temperature: -30°C ~ +80°C.
4. Main LCD Driver: ST7735V3.
5. Backlight: 2 CHIP-WHITE LED.
6. General Tolerance: ±0.20 mm.
7. ROHS Compliance: Yes.
8. Pitch: 1.0mm * 23 = 23.00mm.
9. FPC Total Thickness: 0.05mm.
10. Double Side Tape (T=0.10mm): Included.
11. Backlight Circuit: I=15X2mA (Constant Current Drive), V=3.3V (Reference Voltage (Reference Voltage).

3.2 Electrical & Interface Specifications

3.2.1 Absolute Maximum Ratings

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)

3.2.3 Pin Description (from mechanical drawing)

The mechanical drawing provides the following pin assignments for the interface. The drawing indicates a 24-pin electrical interface with the following definition:

Interface Summary:

• 4-Line Serial Interface: The module uses a 4-line serial interface for communication.
• Backlight: Dedicated LEDA (Anode, Pin 1) and LEDK (Cathode, Pin 2) pins.
• Power: The drawing shows multiple power and ground pins.

3.2.4 Serial Interface Timing Characteristics (4-line Serial)

Conditions: Ta=25 °C, VDDI=1.65~3.7V, VDD=2.5~3.7V.

A. Write Operation Timing:

B. Read Operation Timing:

Key Timing Observations:

• Write timing is faster than read timing: Write clock cycle (TSCYCW) is 20ns (50 MHz), while read clock cycle (TSCYCR) is 150ns (6.67 MHz).
• Data setup/hold time: TSDS = TSDH = 10ns.
• Chip select hold time: TCHW = 40ns minimum.

3.2.5 Backlight Unit

Backlight Circuit Diagram (from document):

PIN(A) → [Backlight Circuit] → PIN(K)
I = 15X2mA (Constant Current Drive)
V = 3.3V (Reference Voltage)

3.3 Optical & Electro-Optical Characteristics (Ta=25°C)

Notes (from document):

Note 1: Definition of Response Time
The response time is defined as the following figure and shall be measured by switching the input signal for "black" and "white". This definition is valid for a normally black display. For a normally white display the opposite definition applies.
The response time definition diagram shows:

• Optical Response (%): Black = 0%, White = 100%
• Tr (Rise Time): Time from 10% to 90% of optical response.
• Tf (Fall Time): Time from 90% to 10% of optical response.
• Tr + Tf = Total Response Time.

Note 2: Definition of Contrast Ratio
Contrast ratio (CR) is defined mathematically by the following formula:
Contrast Ratio = Luminance measured when LCD on the "White" state / Luminance measured when LCD on the "Black" state

Note 3: Definition of Viewing Angle
Viewing angle is the angle at which the contrast ratio is greater than 10. Angles are determined for the horizontal or x axis and the vertical or y axis with respect to the z axis which is normal to the LCD surface.
The viewing angle definition diagram shows:

• Normal: θx = θy = 0°
• θy+ = 90° (12 o'clock direction, Top)
• θx+ = 90° (3 o'clock direction, Right)
• θx- = 90° (9 o'clock direction, Left)
• θy- = 90° (6 o'clock direction, Bottom)
• IC Bonding Pad location indicated on the diagram.

Note 4: Backlight Circuit

• Circuit diagram: PIN(A) → [Backlight] → PIN(K)
• Drive condition: I = 15X2mA (Constant Current Drive), V = 3.3V (Reference Voltage)

3.4 Version Record

4. Application Guidelines & Critical Notes

Intended Use

• Low-cost IoT devices
• Simple user interfaces requiring compact size
• Applications where resolution requirements are modest (128x160)
• Wearable devices, smart home controls, miniature instruments

Critical Design Considerations

1. Interface (4-Line Serial): This module uses a 4-line serial interface for communication. The host MCU must have at least 5 GPIOs (SCL, SDA, D/CX, CSX, RESET) to drive the display.

2. Power Supply:

   • Provide stable VCC (2.75V typical) for the main logic.
   • Provide stable IOVCC (1.8V typical) for the I/O interface.
   • The backlight requires a constant-current LED driver set to 30 mA (15mA x 2) at 3.3V (Reference Voltage).

3. Interface Timing Requirements:

   • For write operations, the serial clock cycle (TSCYCW) must be ≥ 20ns (50 MHz maximum). This is a fast write speed requiring careful PCB layout.
   • For read operations, the serial clock cycle (TSCYCR) must be ≥ 150ns (6.67 MHz maximum).
   • Data setup time (TSDS) and data hold time (TSDH) must be ≥ 10ns.
   • Chip select setup time (TCSS): 15ns for write, 60ns for read.

4. Mechanical Integration:

   • Module Outline: 34.7mm (H) × 46.7mm (V) × 2.5mm (D).
   • Active Area: 28.03mm × 35.04mm.
   • FPC: The module uses a 24-pin FPC with 1.0mm pitch (23 pins × 1.0mm = 23.00mm total width).
   • FPC Total Thickness: 0.05mm.
   • Double Side Tape: Included (T=0.10mm).

5. Viewing Angle Characteristics:
   This is a TN panel with the following viewing angle performance (CR > 10):

   • Top (12 o'clock): 45° (Typ)
   • Bottom (6 o'clock): 20° (Typ)
   • Left (9 o'clock): 45° (Typ)
   • Right (3 o'clock): 45° (Typ)

   Best image quality is obtained when viewing from the top (12 o'clock) direction.

6. Optical Performance:

   • Response Time: 30ms (Typ), 60ms (Max) – suitable for most GUI applications.
   • Contrast Ratio: 200 (Min), 300 (Typ) – adequate for indoor use.
   • Transmittance: 6.21% (Min), 6.8% (Typ).
   • White Chromaticity (CIE1931): Wx = 0.309, Wy = 0.327 (Typical).

7. 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 24-pin FPC – handle with care.
• The module is 2.5mm thick – be careful when handling to avoid flexing.

5. Conclusion & Design-In Support

The LS0177T02-S-V1 specification details a compact 1.77-inch TN display module with a 4-line serial interface — an excellent choice for cost-sensitive, simple display applications.

Key Strengths:

1. Compact Size: 34.7mm × 46.7mm — suitable for space-constrained applications.
2. Standard Resolution (128x160): Suitable for simple icons, text, and basic UIs.
3. Standard 4-Line Serial Interface: Requires only 5 GPIOs for communication, simplifying integration.
4. Fast Write Speed: 20ns write cycle (50 MHz) allows for rapid screen updates.
5. Good Transmittance: 6.8% (Typ) – allows for efficient backlight usage.
6. Comprehensive Timing Documentation: Detailed serial interface timing parameters provided.

Main Design Focus:

• The critical design task is properly implementing the serial interface timing, especially the 20ns write cycle requirement which demands careful PCB layout with short trace lengths.
• Supporting requirements:
  • Provide stable VCC (2.75V typical) and IOVCC (1.8V typical) power.
  • Provide a constant-current backlight driver set to 30 mA at 3.3V (Reference Voltage).
  • Mechanical integration — the module outline is 34.7mm × 46.7mm × 2.5mm.
  • FPC connector — verify the 24-pin FPC with 1.0mm pitch.

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.