Itel ACE 2N Mobile Charging Diagram And Repair Ways

Download the PDF for the Itel Keypad Mobile full charging schematic diagram and pinout. Repairing ways and voltage diagram. ExploreDetails com.

Section 1: Charging Circuit Input

The primary input to the charging system is the 5V supply provided through the charging port. Let’s break this down:

1.1 Input Voltage (5V)

  • The charging port, marked as "C/C Positive 5V," is where the external power adapter connects.
  • This 5V input is the universal charging voltage for most mobile devices, balancing efficiency and compatibility with USB standards.

1.2 Protection Circuit

  • Before entering the critical components, the input passes through a 200-ohm resistor. This resistor serves multiple purposes:
    • Current Limiting: Limits the inrush current when the charger is connected, protecting downstream components.
    • Transient Protection: Reduces the effects of voltage spikes caused by fluctuating input.

1.3 Voltage Regulation

  • The input voltage is further processed by the charging IC (Integrated Circuit), which ensures the following:
    • Converts the 5V to a stable output voltage required for battery charging (4.2V in this case).
    • Monitors and adjusts the charging current and voltage for safety.
    • Prevents overcharging by cutting off the supply when the battery reaches full charge.

Section 2: Current-Sensing Resistor and Charging Path

2.1 Current Sensing with R068

  • A low-value resistor labelled R068 (likely 68 milliohms) is placed in series with the charging line. Its purpose is to measure the charging current:
    • The voltage across this resistor is proportional to the current (Ohm’s Law: 
      V=I×RV = I \times R
    • The charging IC uses this voltage drop to monitor the charging current, ensuring it stays within safe limits.

2.2 Battery Connection

  • The positive terminal of the battery (4.2V) is connected through this resistor. This ensures that the charging current flows from the IC to the battery while being monitored.

Section 3: Intermediate Resistor Network

The charging circuit includes several resistors with specific values (e.g., 100 ohms, 10K ohms). These form part of the IC’s control and signal conditioning circuitry.

3.1 100-Ohm Resistor

  • This resistor helps in:
    • Current Limiting: Protects the IC’s input from excess current.
    • Signal Conditioning: Ensures the charging signal remains clean and noise-free.

3.2 10K-Ohm Resistor

  • A high-value resistor like this is typically used in voltage divider circuits. In this setup:
    • It scales down the voltage to a range readable by the charging IC.
    • Provides reference voltages for the IC’s internal circuits.

Section 4: Charging IC Operation

The charging IC is the central component of this system. It performs the following functions:

4.1 Voltage Regulation

  • The IC steps down the 5V input to a stable 4.2V, the standard charging voltage for lithium-ion batteries.

4.2 Current Control

  • Monitors the current through the sensing resistor (R068) and adjusts it based on the battery's state of charge:
    • Constant Current Mode: A high current is supplied initially to charge the battery quickly.
    • Constant Voltage Mode: Current gradually decreases as the battery approaches full charge.

4.3 Protection Features

  • Prevents overcharging by cutting off the current once the battery reaches full capacity.
  • Includes short-circuit and thermal protection, ensuring safety.

Section 5: Battery Signal Interface (BSI)

The Battery Signal Interface (BSI) is critical for communication between the battery and the device. It allows the phone to identify the battery type, charge level, and health status.

5.1 Role of BSI

  • The BSI pin transmits signals about:
    • Battery type (e.g., lithium-ion or lithium-polymer).
    • Charge status (full, charging, or low).
    • Temperature monitoring for safety during charging.

5.2 Resistor Network in BSI Circuit

  • 10-Ohm Resistor:
    • It helps stabilize the signal between the BSI pin and the battery.
    • Protects the BSI line from sudden current spikes.
  • 5.70K-Ohm Resistor:
    • Works as part of a voltage divider, scaling the battery's signal voltage to a readable level for the device.
  • 20-Ohm Resistor:
    • This additional resistor balances the BSI signal or acts as a pull-up/pull-down resistor to maintain a steady signal level.

5.3 Communication with Charging IC

  • The charging IC uses the BSI signal to adjust the charging parameters dynamically, ensuring optimal performance and safety.

Section 6: Ground Connection

The battery's negative terminal and other components are connected to the ground plane of the PCB (Printed Circuit Board). This ground connection:

  • Provides a return path for current.
  • Ensures all components operate with a common reference voltage.

Section 7: Practical Considerations

7.1 Importance of Component Values

  • Resistor values (e.g., 200 ohms, 10K ohms) are carefully selected to ensure the circuit functions correctly. Any deviation can affect the charging efficiency or damage components.

7.2 Heat Management

  • The charging IC and sensing resistor (R068) may generate heat during operation. Proper PCB layout and thermal management are essential to prevent overheating.

7.3 Testing and Troubleshooting

  • To diagnose issues in the charging circuit:
    • Measure the voltage across R068 to verify the current flow.
    • Check for continuity and proper voltage levels at key points (e.g., battery positive terminal, BSI pin).
    • Inspect resistors and the IC for signs of damage.

Section 8: Pinout Summary

8.1 Charging Port Pinout

  • Positive Pin (C/C Positive):
    • Receives 5V from the charger.
  • Negative Pin:
    • Connected to ground, completing the circuit.

8.2 Battery Pinout

  • Positive Terminal (4.2V):
    • Supplies power to the phone’s circuitry.
    • Receives charging current from the IC.
  • Negative Terminal:
    • Connects to ground.
  • BSI Pin:
    • Transmits battery status signals to the phone.

Section 9: Integration with the Mobile Device

The charging circuit is just one part of the mobile device. It interacts with other subsystems like:

  • Power Management IC (PMIC):
    • Distributes power to various components.
  • Main Processor:
    • Uses BSI data to display battery status to the user.
  • Thermal Sensors:
    • Monitor temperature to prevent overheating.

Section 10: Summary of Circuit Behavior

Normal Operation

  1. 5V input is provided via the charging port.
  2. The 200-ohm resistor limits inrush current.
  3. The charging IC regulates voltage and current, delivering 4.2V to the battery.
  4. The BSI pin communicates the battery status to the phone.
  5. Current flow is monitored through R068, ensuring safety.

Fault Scenarios

  • Overvoltage:
    • Protection features in the IC prevent damage.
  • Short Circuit:
    • The IC shuts down the output to protect the battery and components.
  • Component Failure:
    • Open or shorted resistors can disrupt the circuit. Diagnosing and replacing faulty components restores functionality.
Supported Model:
itel ACE 2N, P110N, it5618n, it2163A, it2182, it2160, L6006, U20, it2171 And More..

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