LM 36273 ORIGINAL Mobile Phone IC

Enhance Your Device’s Efficiency

The LM 36273 ORIGINAL Mobile Phone IC is built to deliver exceptional performance for your mobile devices. Designed to maintain optimal power management, this IC ensures your device operates smoothly and efficiently—perfect for professionals and tech enthusiasts alike. LM 36273 ORIGINAL Mobile Phone IC

Reliable and Durable Design

Manufactured to meet high-quality standards, the LM 36273 ORIGINAL IC boasts outstanding durability and reliability. Its advanced design ensures long-term functionality, making it a must-have component for any mobile device that demands dependability. LM 36273 ORIGINAL Mobile Phone IC

Perfect Compatibility for Tech Solutions

With a versatile design, the LM 36273 ORIGINAL Mobile Phone IC is compatible with a wide range of mobiles and devices. Whether you’re repairing or upgrading, this IC is a practical solution for enhancing the performance of modern mobile gadgets. LM 36273 ORIGINAL Mobile Phone IC

The LM36273 is a high-performance, integrated three-channel White LED (WLED) driver and LCD bias supply manufactured by Texas Instruments. Primarily found in modern smartphones like the Redmi Note 8, Honor 20i, and Nova 2, it is a critical “Graphics and Light Combo” IC responsible for both screen illumination and the voltages required for the display to render images. LM 36273 ORIGINAL Mobile Phone IC

Technical Overview

The LM36273 is designed to minimize board space in slim mobile architectures. It integrates a backlight boost converter capable of driving up to 24 LEDs (three parallel strings) and an LCD bias boost that provides the positive and negative rails ( $\pm 4\text{V}$ to $\pm 6.5\text{V}$ ) necessary for LCD panels.

Detailed Specifications Table

Feature / Parameter	Specification Details
Manufacturer	Texas Instruments (TI)
Model Number	LM36273
Package Type	DSBGA (24-pin), Ultra-compact
Body Size	2.44 mm × 1.67 mm
Input Voltage Range	2.7V to 5V (Typical Li-ion Battery range)
Number of LED Channels	3 Parallel White LED Strings
Max Output Voltage ( $V_{OUT}$ )	Up to 29V (Backlight Boost)
LED Current per Channel	60 µA to 30 mA
Dimming Control	11-Bit Exponential and Linear Dimming
Control Interfaces	$I^2C$ Bus and Logic Level PWM
LCD Bias Voltages	Programmable $\pm 4\text{V}$ to $\pm 6.5\text{V}$
LCD Bias Resolution	50-mV steps
Peak Efficiency	Up to 92%
Operating Temperature	-40°C to 85°C
External Components	Requires 4.7-µH to 15-µH Inductor

Key Functions in Mobile Devices

1. Advanced Backlight Management

The IC utilizes a constant current regulation technique. This is vital for mobile phones because it prevents flicker and ensures uniform brightness across the display, even when the battery voltage drops. The 11-bit dimming allows for incredibly smooth transitions between brightness levels, which is what makes “Adaptive Brightness” feel seamless to the user.

2. Integrated LCD Bias Power

Most LCDs require two specific voltages to orient the liquid crystals: a positive voltage ( $V_{POS}$ ) and a negative voltage ( $V_{NEG}$ ).

LM36273 generates both using a single boost converter and an inverting charge pump.
It includes auto-sequencing, which ensures the positive rail turns on slightly before the negative rail (or vice-versa) to prevent damage to the display panel during boot-up.

3. Energy Efficiency

With a peak efficiency of 92%, this IC is designed to maximize battery life. It reduces power consumption by dynamically adjusting its switching frequency and output based on the display’s current needs.

Hardware Pin Configuration

The LM36273 uses a 24-ball BGA (Ball Grid Array) layout. Common pins include:

VBATT: Main power input from the battery.
SDA/SCL: $I^2C$ data and clock lines for communication with the phone’s CPU.
LED1, LED2, LED3: Current sinks for the backlight strings.
VPOS / VNEG: Outputs for the LCD display power.
PWM: Input for hardware-level brightness control.

Repair & Compatibility Notes

In the mobile repair industry, the LM36273 is often referred to as the “Light IC” or “Graphics IC”.

Common Symptoms of Failure: A phone that turns on (vibrates or makes sound) but has a completely black screen, or a screen that is visible only under a bright flashlight (indicating backlight failure).
Replacement: Since this is a BGA chip, replacement requires professional SMD soldering tools, including a hot air station and high-quality flux. It is often cross-compatible with specific versions of the LM36272 (2-channel) or LM36274 (4-channel) depending on the circuit design, but using the original LM36273 is recommended for stability.

LM 36273 ORIGINAL Mobile Phone IC