Content last revised on November 21, 2025
LM057QC1T08: Sharp 5.7-inch 320x240 QVGA Color CSTN-LCD Module with Integrated Inverter
The Sharp LM057QC1T08 is a 5.7-inch CSTN color display module engineered for simplified integration into embedded systems. Delivering a dependable 320x240 QVGA resolution with a brightness of 120 cd/m², this panel features an Integrated CCFL Inverter to streamline design. Key benefits include a reduced external component count and a simplified connection to 8-bit microcontrollers. This module provides a cost-effective color display option for systems built around a standard parallel interface, often avoiding the need for a complete system redesign.
Key Parameter Overview
Decoding Specifications for Legacy System Integration
The technical specifications of the LM057QC1T08 are tailored for straightforward implementation in industrial controls, test equipment, and other embedded systems where reliability and ease of integration are paramount. The following table highlights the key performance metrics derived from the official datasheet.
| Parameter | Specification |
|---|---|
| Manufacturer | Sharp |
| Model | LM057QC1T08 |
| Screen Size | 5.7 inch (14 cm) |
| Resolution | 320(RGB) x 240 (QVGA) |
| Display Technology | CSTN (Color Super-Twisted Nematic) |
| Display Mode | Transmissive, Normally White |
| Luminance | 120 cd/m² (Typ.) |
| Contrast Ratio | 25:1 (Typ.) |
| Interface Type | 8-bit Parallel Data |
| Backlight System | 1 x CCFL with Integrated Inverter |
| Backlight Lifetime | 20,000 Hours (Typ.) |
| Operating Temperature | 0°C to +50°C |
| Outline Dimensions | 154.0(W) x 115.4(H) x 11.0(D) mm |
Download the LM057QC1T08 datasheet for detailed specifications and performance curves.
Application Scenarios & Value
System-Level Benefits in Industrial Control and Instrumentation
For legacy industrial HMIs requiring a reliable QVGA color display with minimal integration overhead, the LM057QC1T08 is a proven solution. Consider an engineering team tasked with repairing an aging piece of laboratory test equipment. The original display has failed, and the system relies on an 8-bit microcontroller with a parallel display output. The LM057QC1T08 serves as an ideal replacement part. Its standard 5.7-inch form factor and 320x240 QVGA resolution ensure that the existing graphical user interface renders correctly without firmware adjustments. Critically, the module's integrated CCFL inverter connects directly to the system's low-voltage DC rail, bypassing the need to source or reverse-engineer a separate, and often obsolete, high-voltage driver. This feature significantly reduces repair complexity and equipment downtime.
The module's architecture is a strong fit for point-of-sale terminals, industrial process controllers, and medical monitoring devices from a previous design generation. What is the main benefit of its integrated inverter? It simplifies system design and reduces external components. Is CSTN technology suitable for video applications? No, its slower response time is optimized for static GUIs. For systems requiring the higher performance of TFT technology in a similar form factor, models like the KCG057QV1DB-G000 provide a potential upgrade path with improved contrast and viewing angles.
Frequently Asked Questions
Engineering Inquiries on Integration and Performance
What is the primary advantage of the integrated CCFL inverter?
It simplifies the overall system design by generating the necessary high-voltage AC for the backlight directly from the module's DC input. This reduces the external component count, saves valuable PCB space, and accelerates the design-in process for various embedded systems.
How does the CSTN technology of the LM057QC1T08 affect its suitability for modern applications?
CSTN (Color Super-Twist Nematic) technology, an early passive-matrix display type, offers a cost-effective color solution. While its viewing angles, contrast ratio (25:1 typ.), and response time (350 ms typ.) are modest compared to modern TFT panels, it is perfectly adequate for the static GUIs found in industrial control panels or instrumentation where wide viewing angles and video playback are not primary requirements.
Is the LM057QC1T08 a direct drop-in replacement for other 5.7" QVGA displays?
While its mechanical dimensions and resolution are standard for the 5.7-inch QVGA class, engineers must meticulously verify the pinout of the parallel interface connector, the required logic voltage levels, and the backlight power connector to ensure full electrical and mechanical compatibility with the target system.
What is the typical lifespan of the CCFL backlight?
The official datasheet specifies a backlight lifetime of 20,000 hours (Typ.). This figure represents the time until the panel's brightness degrades to 50% of its initial value when operated at 25°C. This is a crucial parameter for calculating maintenance schedules and assessing the total cost of ownership in long-life industrial equipment.
Technical Deep Dive
A Closer Look at the CSTN Panel and Integrated Backlight Driver
The architecture of the Sharp LM057QC1T08 reflects a design philosophy focused on functional sufficiency and integration simplicity. Its core display technology, CSTN technology, is a passive-matrix addressing scheme. Unlike active-matrix TFT, where each pixel is controlled by a dedicated transistor, CSTN addresses pixels at the intersection of an entire row and column. This can be analogized to a city grid where traffic on a whole street is controlled simultaneously, which is simpler but can lead to crosstalk and slower state changes. This is the source of its characteristic 350 ms response time, making it ideal for displaying stable information rather than dynamic video.
The second key design element is the integrated backlight unit. The module incorporates not just the CCFL tube but also the inverter circuit required to drive it. This is a significant engineering convenience. Driving a CCFL requires converting a low DC voltage (e.g., 5V) into a high-frequency, high-voltage AC waveform (often around 1000V). Designing such a circuit involves careful management of magnetics, high-voltage components, and potential EMI. By integrating this function, the LM057QC1T08 presents a simple DC-in interface to the system designer, much like a modern appliance with a built-in power supply versus one requiring a specific external adapter. This simplifies power rail design and accelerates regulatory compliance.
As a component designed for longevity and serviceability, the LM057QC1T08 remains a relevant solution for maintaining the operational life of a vast installed base of industrial and commercial equipment. Its design prioritizes compatibility with established system architectures, ensuring that essential machinery can continue to function without costly and complex redesigns.
