LM 3697/D8 ORIGINAL Mobile Phone IC

Premium Quality and Reliability

The LM 3697/D8 ORIGINAL Mobile Phone IC is engineered to deliver exceptional performance and ensure your device operates smoothly. Crafted with precision, this IC offers unmatched quality you can rely on for optimal functionality in mobile devices. LM 3697/D8 ORIGINAL Mobile Phone IC

Designed for Compatibility

This mobile phone IC is specifically designed to fit seamlessly within a wide range of devices, ensuring compatibility and hassle-free integration. Perfect for repairs, replacements, or upgrades, the LM 3697/D8 is a trusted choice for professionals and DIY enthusiasts alike. LM 3697/D8 ORIGINAL Mobile Phone IC

Durable and Efficient

Built to last, the LM 3697/D8 ORIGINAL IC ensures durability and efficiency in every application. With its top-notch design and reliable technology, it prolongs the lifespan of your mobile phone and enhances performance effortlessly. LM 3697/D8 ORIGINAL Mobile Phone IC

The LM3697 (often marked with the code D8 in mobile repair circles) is a high-efficiency triple-string LED driver designed primarily for smartphone backlight units. Manufactured by Texas Instruments, it is a staple in the “Light IC” section of Android motherboards, particularly in devices from Oppo, Vivo, and Xiaomi. LM 3697/D8 ORIGINAL Mobile Phone IC

Below are the full technical specifications, pinout details, and functional overview. LM 3697/D8 ORIGINAL Mobile Phone IC

1. Technical Specifications Table

The LM3697 is a boost-converter-based driver that manages power for the display’s backlighting LEDs.

Parameter	Specification Details
Part Number / Marking	LM3697 / D8
Manufacturer	Texas Instruments
Topology	Inductive Boost (Step-Up)
Input Voltage Range ( $V_{IN}$ )	$2.7V$ to $5.5V$
Output Voltage ( $V_{OUT}$ )	Up to $40V$ (Adaptive)
Number of Channels	3 Parallel High-Voltage LED Strings
Max Current per Channel	$30mA$
Peak Efficiency	Up to $90\%$
Switching Frequency	Selectable $500kHz$ or $1MHz$
Dimming Resolution	11-Bit (2048 steps) Exponential or Linear
Interface	$I^2C$ Compatible
Protection Features	OVP (16V, 24V, 32V, 40V), OCP, Thermal Shutdown
Operating Temperature	$-40°C$ to $+85°C$ (Ambient)
Package Type	12-pin DSBGA (1.64 mm x 1.29 mm)

2. Pin Configuration (12-Pin DSBGA)

Understanding the pinout is critical for motherboard-level troubleshooting and “reballing” the IC.

Pin Number	Name	Function
A1	VIN	Power Supply Input
A2	SW	Drain of the internal MOSFET (Switching Node)
A3	HVLED1	Current Sink Input for LED String 1
B1	SCL	$I^2C$ Serial Clock Input
B2	PGND	Power Ground
B3	HVLED2	Current Sink Input for LED String 2
C1	SDA	$I^2C$ Serial Data Input/Output
C2	HWEN	Hardware Enable (Active High)
C3	HVLED3	Current Sink Input for LED String 3
D1	PWM	PWM Input for CABC (Content Adjustable Backlight Control)
D2	OVP	Over-Voltage Protection Sense Pin
D3	GND	Analog Ground

3. Key Functional Features

High-Resolution Dimming

The LM3697 stands out due to its 11-bit dimming resolution. This allows for extremely smooth transitions in screen brightness, eliminating the “flicker” or “stepping” effect seen in lower-quality drivers. It supports both exponential dimming (which matches the human eye’s perception of light) and linear dimming. LM 3697/D8 ORIGINAL Mobile Phone IC

Integrated 1-A/40-V MOSFET

By integrating a powerful MOSFET, the IC minimizes the number of external components needed on the crowded mobile motherboard. It only requires an external inductor, a Schottky diode, and a few capacitors to function as a full boost converter. LM 3697/D8 ORIGINAL Mobile Phone IC

Adaptive Boost Control

The IC “senses” the forward voltage of the LED strings and automatically adjusts its boost output to provide just enough headroom. This prevents power wastage, which is why it can reach 90% efficiency, directly contributing to longer battery life in smartphones. LM 3697/D8 ORIGINAL Mobile Phone IC

4. Common Repair Symptoms (Mobile Repair Context)

In the mobile repair industry, the D8 IC is frequently replaced when a phone has “no light” but still shows a “graphic” (visible under a bright torch).

No Backlight: The most common failure. Often caused by water damage near the HVLED pins or a shorted boost capacitor.
Flickering Screen: Indicates unstable current regulation or a failing internal MOSFET.
Half-Dark Screen: Since the IC has 3 channels, a failure in one channel (e.g., HVLED1) can result in one-third of the screen remaining dark.
Overheating: If the IC or the surrounding area (especially the boost coil) gets extremely hot, it usually indicates a short circuit in the output line ( $V_{OUT}$ ).

Replacement Pro-Tip

The LM3697 is a BGA (Ball Grid Array) chip. When replacing it:

Air Temperature: Use approximately $330°C - 350°C$ for removal.
Directionality: Note the “dot” on the chip corner for correct orientation; installing it backwards will cause a short and potentially damage the CPU’s $I^2C$ lines.

LM 3697/D8 ORIGINAL Mobile Phone IC