Decoding the Core Power Supply of TFT Display Screens: The "Power Code" Behind Chinese Intelligent Manufacturing

Behind a vibrant, colorful, and reliable TFT display screen lies its precise "heart" – the power supply system. From smartwatches to high-end phones and industrial equipment, the Chinese liquid crystal display screen industry is rapidly advancing. Its core power design technology has become a key battleground for quality competition. This article delves into the core power supply modes of TFT display screens, revealing how Chinese manufacturers drive display quality leaps through technological innovation.

1. Simplicity & Efficiency for Small Sizes: POWR Mode

Power Core: A single VCC/VDD (3.3V or 2.8V) supply powers the internal boost circuit and digital logic.

Key Requirement: All input/output signal levels must strictly match the VCC/VDD voltage.

Application: Ideal for small-sized TFT display screens like smart wearables and small handheld devices. Chinese manufacturers show significant advantages in integration and power consumption control for such solutions.

2. Advanced Choice for Small Sizes/Phones: Dual-Voltage POWER Mode

Power Core: VCC (3.3V) handles the boost circuit, while IOVCC (1.8V) exclusively powers the interface and digital logic.

Key Requirement: Signal levels must match IOVCC (1.8V).

Application: Widely used in small-sized display screens and early phone screens. The Chinese supply chain is highly competitive in providing cost-effective, stable 1.8V logic level solutions.

3. High-Quality Engine for Phone Screens: Multi-Voltage Synergy POWER Mode

Power Core:

VSP/AVDD (+5.5V): Drives the positive boost circuit to illuminate pixels.

VSN/AVEE (-5.5V): Drives the negative boost circuit for precise control.

IOVCC (1.8V): Ensures stable interface and logic operation.

Key Requirement: Signal levels must strictly match IOVCC (1.8V).

Application: Standard for modern phone screens, demanding extremely high voltage accuracy. Leading Chinese panel manufacturers have achieved breakthroughs in designing complex Power Management ICs and supporting solutions (refer to "TFT&AMOLED Power Circuit Reference.pdf"), underpinning the rise of domestically produced high-end phone display screens.

4. Pursuing Ultimate Display Quality: Discrete Power Mode

Power Core:

VCC (3.3V): Powers interface and digital logic (signal levels match VCC).

AVDD: Powers Gamma correction & Source driver (directly impacts color, contrast).

VGH: TFT transistor turn-on voltage (high level).

VGL: TFT transistor turn-off voltage (low level).

VCOM: The "Lifeline" of the Display Screen (Common electrode voltage, critically affecting display uniformity, flicker, image retention).

The Art of VCOM Fine-Tuning:

Chinese engineers understand VCOM precision is paramount for image quality. Minor VCOM variations exist even within the same batch of display screens.

High-End Recommendation: For optimal display effects, reserve a 10K voltage-dividing resistor and a parallel 4.7-10uF capacitor on the path from AVDD to VCOM. This effectively filters noise and enhances stability (refer to "Digital Screen - Peripheral DC-DC Boost Reference Circuit.pdf").

For special TFT glass like IPS or wide-temperature types, operational amplifiers (OP) are required to precisely set VCOM, ensuring excellent performance across all viewing angles and temperature ranges.

Critical Reminder from Chinese Intelligent Manufacturing: Protecting Screen Lifespan

Regardless of the power mode used, Chinese liquid crystal display screen manufacturers strictly emphasize: During sleep or shutdown, power and display signals MUST be cut off simultaneously! Any delay can cause screen "polarization," leading to stubborn image retention. This is an ironclad rule to ensure user experience and product longevity.

Conclusion:

From ingenious single-supply designs to complex multi-voltage synergy, the power scheme of TFT display screens is the cornerstone of display quality. The Chinese liquid crystal display screen industry, leveraging deep power technology expertise and rapid iteration capabilities, is continuously innovating in the core "power" domain of display screens. This brings global markets higher-performance, more reliable, and cost-competitive display solutions. Understanding and effectively applying these power modes is key to unlocking the full potential of every Chinese display screen!

About CNK

Founded in Shenzhen in 2010, CNK Electronics (CNK in brief) expanded the world leading factory in Longyan, Fujian in 2019. It is a specialized and innovative enterprise specializing in the design, development, production and sales of display products. CNK provides customers with a full range of cost-effective small and medium-sized display modules, solutions, and services with excellent quality worldwide. Oriented in technology and high quality, CNK keeps sustainable development, works to offer customers  better and stable services.