Signals the main charging IC to adjust charge current and voltage thresholds dynamically. 3. General Pinout Structure and Signal Descriptions
The EC operates on a standby power rail (usually +3VS5 or +3V_EC ), meaning it is powered up the moment a power adapter or charged battery is connected to the laptop. Its responsibilities include:
: Widely encountered as IT8995E-128 CX , with variant suffixes like CXA, CXS, and DXA .
Measure the voltage on the VSTBY pins (typically 3.3V). If this voltage is missing or pulling low, the chip may have an internal short circuit.
The device includes 128KB of internal embedded Flash memory, allowing for in-system programming (ISP). it8995e 128 datasheet
: Handles General Purpose Input/Output ( GPIO ) pins for status LEDs, lid switches, and power button triggers. Pin Configuration and Architecture Overview
Remove the laptop battery and charger completely.
8051-compatible or proprietary risk core optimized for low power consumption.
Notebook motherboards, communications equipment, enterprise systems Signals the main charging IC to adjust charge
+---------------------------------------------+ | ITE IT8995E-128 | | | | +-------------------+ +----------------+ | | | Processor Core | | 128KB eFlash | | | +-------------------+ +----------------+ | | | | +-------------------+ +----------------+ | | | Keyboard Matrix | | Power Sequence | | | +-------------------+ +----------------+ | | | | +-------------------+ +----------------+ | | | ADC / Thermal PWM | | GPIO Block | | | +-------------------+ +----------------+ | +---------------------------------------------+ Hardware Functional Blocks
If the EC firmware corrupts or its thermal ADC lines fail, it may spin the cooling fan at 100% continuously as a failsafe.
: The EC reads its internal 128KB flash memory to initialize the GPIO pins.
Hobbyists reverse-engineering old laptops use the datasheet to access GPIO pins for custom projects, such as reading battery status LEDs or adding external sensors. The device includes 128KB of internal embedded Flash
AC adapter validation (reading the adapter type and wattage via a center-pin data line).
ITE provides programming utilities such as (Windows‑based) that can update the EC firmware over the LPC bus. However, these tools are intended for OEM use and are not widely available to end users.
Hardware reset input. Must be held high (3.3V) for the chip to run its internal code.
This article is based on publicly available information from component distributors, laptop repair forums, and hardware analysis. It is . Always refer to original manufacturer sources where available, and exercise caution when replacing or reprogramming sensitive embedded controllers. The author and publisher assume no responsibility for damage resulting from the use of this information.
: The chip often requires programming after being soldered to a motherboard, which can be done via the I2C or keyboard interface.