Mobile Phone IC For 358S-1939 Original
The 358S-1939 is a specialized power management integrated circuit (PMIC) primarily functioning as a USB Charging Controller and Interface IC. It is an essential component in various mid-range smartphones and tablets, particularly those within the Samsung Galaxy Tab, Oppo, and Asus product lines.
This IC acts as a bridge between the charging port and the main system, ensuring that power intake is regulated and that data signals are correctly routed for USB connectivity.
Technical Specifications: 358S-1939
| Feature | Specification Detail |
| Model Number | 358S-1939 |
| Component Type | Secondary PMIC / USB Charging & Interface IC |
| Package Type | 30-Pin Micro-BGA (Ball Grid Array) |
| Supported Devices | Samsung Tab A (T580/T585), Tab E (T560), Oppo R8007, Asus Zenfone |
| Input Voltage ($V_{BUS}$) | 3.8V to 5.2V (Standard USB supply range) |
| Output Current | Supports up to 5.0A (Max system/charging current) |
| Operating Temp | -40°C to +125°C |
| Supply Voltage | 1.5V to 5V (Internal logic/supply range) |
| Communication | $I^2C$ Interface for charging status and control |
| Weight | Approx. 0.01kg / 0.02lb |
Core Functional Roles
The 358S-1939 is a “multi-tasking” controller designed to offload specific power and interface duties from the main processor.
1. Switching Battery Charger
The IC manages the Switch-Mode Battery Charger (SMBC) process. It efficiently converts the 5V input from a USB wall adapter or PC down to the battery’s specific charging voltage (typically around 4.2V to 4.4V). Its high efficiency helps prevent the device from heating up excessively during rapid charging cycles.
2. USB Interface & OTG Control
This IC is the “gatekeeper” for the micro-USB or USB-C port. It identifies the type of cable plugged in—whether it is a standard charger, a data sync cable, or a USB-OTG accessory (like a mouse or flash drive). It manages the D+ and D- data lines to ensure proper communication between the phone and external peripherals.
3. Power Path Protection
Because the 358S-1939 is directly in the path of the incoming electrical current, it includes Over-Voltage Protection (OVP) and Thermal Shutdown features. If a faulty charger sends a spike of high voltage, this IC is designed to fail first, sacrificing itself to protect the more expensive CPU and Internal Memory of the device.
Common Symptoms of Failure
The 358S-1939 is highly susceptible to damage from liquid ingress, voltage spikes, or faulty third-party cables.
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“Plugged in, Not Charging”: The phone recognizes the cable, but the battery percentage never increases or actually drops while plugged in.
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No Power (Dead): If the IC develops an internal short to ground, it can pull down the main power rail ($V_{PH\_PWR}$), preventing the phone from booting entirely.
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USB Recognition Issues: The device charges normally but cannot be seen by a computer for file transfers or software flashing.
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OTG Failure: The device works fine otherwise but fails to recognize any OTG accessories like USB drives or keyboards.
Repair & Installation Notes
The 358S-1939 is a BGA component, meaning the connection points are microscopic solder balls located underneath the chip.
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Pin 1 Orientation: Always pay attention to the Pin 1 marker (a small dot on one corner). Installing the chip backwards will result in an immediate short circuit.
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Heat Profile: Use a hot air station set to approximately 340°C – 355°C for removal and installation. Ensure you use a high-quality no-clean flux to prevent solder bridges between the 30 pins.
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Pre-Solder Cleaning: Since the pins are very close together, use a soldering wick to ensure the motherboard pads are perfectly flat before placing the new IC.
