Mobile Phone IC For SM5705R Original
The SM5705R is a specialized power management and USB charging control integrated circuit (IC) manufactured for Samsung’s mid-to-high-range mobile devices. It is a variant of the SM5705 family, specifically optimized for thermal efficiency and fast-charging protocol handshakes.
Below is the technical specification and a detailed breakdown of its role in mobile hardware.
Technical Specifications: SM5705R IC
| Feature | Specification Detail |
| Model Number | SM5705R |
| Component Type | Secondary PMIC / USB Charging Controller |
| Package Type | 94-Pin BGA (Ball Grid Array) |
| Input Voltage ($V_{BUS}$) | 5.0V (Standard) / Supports up to 9V (AFC) |
| Charging Protocol | Samsung Adaptive Fast Charging (AFC) / BC 1.2 |
| Interface | $I^2C$ Serial Interface |
| Functions | Battery Charging, OTG Power, USB Switch |
| Operating Temp | $-40°C \text{ to } +125°C$ |
| Protections | Over-Voltage (OVP), Thermal Shutdown, ESD Protection |
Core Functional Roles
The SM5705R serves as the “gatekeeper” between the charging port and the rest of the phone’s internal circuitry.
1. Charging Logic & Management
The SM5705R manages the Constant Current (CC) and Constant Voltage (CV) charging phases for Lithium-Ion batteries. It communicates with the wall adapter to negotiate the highest safe wattage, enabling Adaptive Fast Charging without stressing the battery cells.
2. USB Interface & Path Control
This IC identifies what is plugged into the USB port. It acts as a high-speed switch, routing data for PC syncing or power for USB OTG (On-The-Go) accessories. It provides the necessary 5V boost to power external peripherals like flash drives.
3. Protection Circuitry
Because it is directly connected to the external world, the SM5705R is the first line of defense against electrical surges. It includes integrated Over-Voltage Protection (OVP) to blow an internal “fuse” logic before high voltage can reach the expensive Application Processor (CPU).
Common Symptoms of a Defective SM5705R
In the repair industry, this chip is frequently replaced due to damage from poor-quality chargers or liquid ingress.
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“Fake Charging”: The phone shows the lightning bolt icon, but the battery percentage never increases or actually drops.
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No Power / Dead: A short circuit inside the SM5705R can pull the main system rail to ground, preventing the device from turning on.
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Temperature Warnings: The phone may display a “Battery Temperature Too Low/High” error even when at room temperature, as this IC processes the battery’s thermistor data.
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No USB Data Connection: The phone charges but is not recognized by any computer for file transfers.
Repair & Installation Notes
The SM5705R is a 94-pin BGA chip, making it a high-difficulty repair requiring professional micro-soldering tools.
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Alignment: Note the Pin 1 marker (the small dot) on the corner. Inverting this chip during installation will cause a catastrophic short circuit.
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Heat Profile: Use a hot air station at $340°C \text{ to } 350°C$. Because it is a large-grid BGA, ensure the board is pre-heated to prevent warping.
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Interchangeability: While the SM5705 and SM5705R look identical, it is best to use the exact suffix (“R”) found on the original board to ensure full compatibility with the device’s firmware.
