Explore the intricate internal circuit of the China Power Bank (Y65). Our guide on IP5189T IC circuit repair will help you troubleshoot and fix issues easily.
IP5189T Power Bank Circuit
Component List
Main IC (IP5189T) - Power bank control and battery management IC, responsible for charging, discharging, and power conversion.
Charging Connector:
Micro USB (Type B) – Input for charging the power bank.
USB Type-C – Bidirectional port for charging and output.
USB Output Slots:
USB-A Output 1 – 5V output for charging devices.
USB-A Output 2 – 5V output for charging devices.
Push Button – For turning the power bank on/off and checking the battery level.
4x Indicator LEDs – Displays battery charge status (e.g., 25%, 50%, 75%, 100%).
NTC Resistor (Thermistor) – Temperature sensing for battery protection.
Battery – 20000mAh Lithium Polymer (Li-Po) battery.
Capacitors – Typically ceramic capacitors (values depend on design) for smoothing voltage.
Resistors – Pull-up, current-sensing, and protection resistors (values depend on design).
Inductors – Likely used in buck-boost conversion circuits (values based on power design).
Protection Diodes – For reverse voltage and overcurrent protection.
MOSFETs – Used for switching in the power conversion and protection circuits.
Full Circuit Details
Power Input (Charging):
The Type B (Micro USB) and Type-C connectors are used for input power, typically from a 5V supply.
The charging input is managed by the IP5189T IC, which handles the voltage regulation and battery charging management. This IC includes protection features for overvoltage, overcurrent, and short-circuit protection.
Battery Charging Circuit:
The IP5189T IC controls the charging of the Lithium Polymer battery (20000mAh).
The NTC resistor (thermistor) monitors the battery temperature, ensuring safe charging by protecting against overheating.
The MOSFETs switch the charging current through the battery.
Capacitors and resistors connected to the IP5189T help smooth out the input voltage and monitor charging current levels.
Boost Converter (Power Output):
The IP5189T has a built-in buck-boost converter to convert the battery voltage (typically 3.7V) to 5V output through the USB slots.
The boost converter uses inductors and capacitors to stabilize the output voltage, ensuring a consistent 5V supply to the USB-A outputs.
MOSFETs are also used here to switch the boost circuit, driven by the control IC.
Output Ports:
There are two USB-A output slots, each providing 5V regulated output for charging devices.
The IP5189T manages the current flow to these outputs, ensuring devices are charged efficiently and safely.
Battery Indicator Circuit:
4 LEDs are connected to the IP5189T, showing the current charge level of the battery.
The push button allows users to check the battery status. When pressed, the IC lights up the LEDs based on the remaining charge (e.g., 25%, 50%, 75%, 100%).
Circuit Working Step by Step
Power Bank Charging:
When a power source (5V) is connected via the Micro USB Type-B or USB Type-C input, the IP5189T starts regulating the incoming voltage.
It uses the NTC resistor to monitor the battery temperature and ensures safe charging conditions.
The battery is charged through a regulated current until it reaches its maximum capacity.
Battery Monitoring:
During charging, the IP5189T monitors the battery voltage and controls the charging cycle.
The LEDs indicate the battery percentage, and the push button can manually show the charge level.
Power Output:
When a device is connected to the USB output ports, the IP5189T boosts the 3.7V battery voltage to 5V using the buck-boost converter.
The output is stabilized by combining inductors, capacitors, and MOSFETs in the boost circuit.
The IC ensures that each USB port delivers the appropriate current for the device connected.
Protection Features:
The IP5189T provides protection from overcurrent, overvoltage, and short circuits.
The NTC resistor ensures the system shuts down or limits charging in case of excessive battery temperatures.
Discharging (Powering Off):
Once the connected device is fully charged, or the power bank is manually turned off using the push button, the IP5189T halts the current output, conserving battery power.