KBC1126-NU is a specialized Keyboard Controller (KBC) and Embedded Controller (EC) manufactured by (now part of Microchip Technology
). It is commonly used in notebook motherboards, particularly within HP and Compaq series laptop designs. Chipset Elektronik Key Specifications & Features : 128-pin TQFP or LQFP. Operating Temperature : Specified for an extended range of cap T sub cap A Core Functions Advanced Power Management : Handles system power sequencing. Keyboard Matrix Scanning : Supports scanning of key matrices to detect key presses. External Firmware : Unlike some other ECs, the KBC1126-NU contain internal programmable flash memory ( e cap F l a s h
); it reads its firmware from an external SPI ROM located on the motherboard. Interfaces
: Includes LPC interface support, LED control, and dedicated interrupt outputs ( cap I cap N cap T Jotrin Electronics Datasheet Resources
You can find the technical documentation and procurement details through the following distributors and datasheet portals: AllDatasheet
: Provides PDF downloads and detailed manufacturer listings. IC-Components
: Lists specific technical specs such as package type (QFP) and RoHS compliance status.
: Hosts schematic overviews and detailed circuit layouts for troubleshooting.
: Offers information on pinouts, pin voltages, and equivalent parts. IC Components replace a faulty chip on a motherboard, or are you designing a new interface circuit KBC1126-NU Schematic Overview | PDF - Scribd
The SMSC KBC1126-NU is a specialized Keyboard Controller (KBC) and Embedded Controller (EC) integrated circuit (IC) widely used in laptop motherboards, particularly within HP and Compaq series from the Ivy Bridge era. When this chip is described as "hot," it typically refers to either a physical overheating failure (a "hot" component) or high demand for its technical datasheet for repair and troubleshooting. Key Technical Specifications KBC1126-NU Go to product viewer dialog for this item.
acts as the "brain" for low-level hardware management before and after the main OS boots. Manufacturer: SMSC (now part of Microchip Technology).
Package Type: LQFP-128 (Low-profile Quad Flat Package) with 128 pins.
Operating Temperature: Specified for an extended range of -40°C to 105°C.
Firmware: Unlike some controllers, it lacks internal programmable flash memory. It reads instructions from an external SPI ROM or the main BIOS chip.
Interface: Utilizes the LPC (Low Pin Count) interface to communicate with the southbridge.
Core: Based on the high-performance 8051 microcontroller architecture. Critical Functions in Laptops The chip is responsible for several vital system tasks:
Power Sequencing: Manages the power-on command and manages different power states (Sleep, Hibernate).
Input Management: Handles the keyboard scan matrix and touchpad signals.
Thermal Monitoring: Interacts with remote temperature sensors and controls the cooling fan speeds based on system load.
Battery Management: Overseas charging protocols and battery status reporting. Why the KBC1126-NU Gets "Hot" (Overheating Issues) kbc1126nu datasheet hot
If a KBC1126-NU chip is physically hot to the touch, it is usually a sign of a critical failure or a short circuit on the motherboard.
SMSC KBC1126NU system contoller or io for Laptop repair ... - CTLAB
The KBC1126-NU is a highly specialized Keyboard Controller (KBC) and Embedded Controller (EC) developed by SMSC (now part of Microchip Technology). While it is often discussed in technical datasheets as a basic input manager, it is actually a "hot" component in the laptop repair and enthusiast community because it serves as the "brain" for critical low-level hardware functions. Key Technical Specifications Package: 128-pin TQFP/LQFP (Thin Quad Flat Package).
Core Architecture: Based on the industry-standard 8051 microcontroller core.
Operating Voltage: Typically 3.3V (ranges from 3.0V to 3.6V).
Temperature Range: Industrial grade, specified for -40°C to 105°C.
Connectivity Interface: Uses the LPC (Low Pin Count) interface to communicate with the laptop's southbridge or chipset. Why It's "Hot": Features & Capabilities The KBC1126-NU
is more than just a keyboard driver; it acts as a system-level manager for several "hot" features:
Firmware Flexibility: Unlike some newer controllers with internal flash, the KBC1126-NU
typically reads its firmware from an external SPI ROM. This makes it a popular target for "BIOS modders" and repair technicians who can fix "no-power" issues by reflashing this external chip.
Advanced Power Sequencing: It manages the transition between power states (S0–S5), controlling when the motherboard "wakes up" or goes to sleep.
Thermal & Fan Control: It is responsible for monitoring system temperatures and adjusting fan speeds. In the Linux community, it is known for its compatibility with tools like NBFC (Notebook Fan Control) to override factory fan curves on older laptops.
Legacy Hardware Support: It handles the 8042-style host interface, ensuring that modern operating systems can still communicate with standard keyboard and touchpad hardware. Common Applications
You will most frequently find this chip on the motherboards of professional-grade laptops from the "Ivy Bridge" era (circa 2012–2014), including: HP EliteBook Series (e.g., 8570w, 8560w). HP ProBook Series (e.g., 4530s, 450 G0).
Custom Embedded Systems requiring a robust 18x8 keyboard scan matrix.
The SMSC KBC1126NU is a specialized keyboard controller (KBC) typically used in laptops and mobile computing devices. It integrates several "Super I/O" functions, such as keyboard scanning, system power management, and analog-to-digital conversion, into a single chip. Key Specifications & Features
Based on the documentation for the KBC1126 series, key features often include:
Integrated Functions: Combines a 8051-based microcontroller core with system-level functions like LPC bus interface, keyboard scan matrix, and PS/2 support.
System Management: Handles low-level power states (ACPI compliance), thermal monitoring, and battery management tasks. KBC1126-NU is a specialized Keyboard Controller (KBC) and
SentinelAlert: SMSC’s proprietary technology designed to monitor system health and provide alerts for potential failures.
Package Type: Typically found in a compact, surface-mount package (e.g., TQFP or QFN) suitable for laptop motherboards. Common Use Cases
Laptop Repair: Often a target for replacement when a laptop fails to power on, has keyboard "ghosting" issues, or experiences fan control failures.
Firmware Programming: In some repair scenarios, the internal flash of the KBC1126NU might need to be reprogrammed using specialized tools (like an RT809H programmer) if the BIOS/EC firmware is corrupted. Technical Resources
You can find more detailed pinouts and electrical characteristics through distributors and datasheet archives:
Datasheet Downloads: High-level summaries and full PDFs are available on ALLDATASHEET.COM and ic2ic.com.
Stock & Sourcing: Retailers like Amazon.in and specialized electronics vendors like WIN-SOURCE or Jotrin Electronics provide images and availability for the physical chip. KBC1126NU stock, price, datasheet. – ic2ic.com
Microtranik,Components,Inc. KBC1126NU. Distributor. for more pls inquire us now. 150750. 17+RoHS. New instock, best quality. 2026- KBC1126NU Datasheet, PDF - ALLDATASHEET.COM
KBC1126NU Datasheet
The KBC1126NU is a highly integrated keyboard controller chip designed for notebook computers. This datasheet provides an overview of the key features, specifications, and functionalities of the KBC1126NU.
Overview
The KBC1126NU is a single-chip keyboard controller that supports both keyboard and embedded controller (EC) functions. It is designed to work with a variety of microprocessors and is compatible with multiple operating systems.
Key Features
Specifications
Functionalities
Pin Configuration
The KBC1126NU is available in a 128-pin QFP package. The pin configuration is as follows:
| Pin Number | Pin Name | Description | | --- | --- | --- | | 1-10 | Keyboard Row 0-9 | Keyboard row scan lines | | 11-20 | Keyboard Column 0-9 | Keyboard column scan lines | | 21-30 | LED Indicators | Num Lock, Caps Lock, and Scroll Lock LED indicators | | 31-40 | USB Interface | USB data and clock lines | | 41-50 | I2C Interface | I2C data and clock lines | | 51-60 | Power Management | Power state, power button, and wake-up event management | | 61-70 | EC Functions | Battery management, thermal management, and system monitoring | | 71-80 | Microprocessor Interface | CPU data and address lines | | 81-90 | Memory Interface | Keyboard buffer and EC buffer interface | | 91-100 | Ground | Ground pins | | 101-110 | Power | Power pins | | 111-120 | NC | No connect | | 121-128 | Reserved | Reserved pins |
Conclusion
The KBC1126NU is a highly integrated keyboard controller chip designed for notebook computers. Its key features, specifications, and functionalities make it an ideal solution for keyboard control, power management, and EC functions. This datasheet provides a comprehensive overview of the KBC1126NU, allowing designers and engineers to integrate it into their designs.
is a highly integrated Embedded Controller (EC) primarily used for laptop keyboard management and system-level monitoring. A "solid feature" to highlight in its datasheet is the Direct Battery Management with SentinelAlert!
, which allows the controller to monitor critical system health—such as temperature and battery voltage—independently of the main processor. Key Feature Highlights for KBC1126NU Intelligent Keyboard Management
: Specialized hardware for scanning complex key matrices and supporting N-key rollover
, which is essential for preventing ghosting in high-performance or gaming laptops. SentinelAlert! System Monitoring
: Provides an autonomous analog monitoring system featuring an 8-channel ADC 3-channel DAC . It can trigger a HW_PROTECT#
thermal event signal without requiring firmware intervention, ensuring system safety even if the main OS hangs. Legacy Host Interface Emulation : Emulates the classic 8042-style host interface
(Port 92 support), ensuring compatibility with legacy software and operating systems while operating on a modern LPC (Low Pin Count) interface Power Efficiency : Supports Connected Standby
modes, making it ideal for mobile devices that need to remain responsive while maintaining low power consumption. Flexible I/O and Peripheral Control : Includes dedicated LED drivers
, multiple GPIOs, and support for external PS/2 devices, allowing for a highly customizable laptop deck (e.g., backlit keys and status indicators). Technical Summary Specification/Detail LPC (Low Pin Count) Monitoring 8-channel, 10-bit ADC Protection Hardware-based thermal event indication ( HW_PROTECT# 156-pin DQFN or 128-pin TQFP (variant dependent)
For full technical specifications and pinout diagrams, you can refer to the KBC1126NU Datasheet on AllDatasheet Microchip’s product listings pin description section for your datasheet? AI responses may include mistakes. Learn more MEC APP Firmware - Microchip Technology
Since the full datasheet is NDA-protected by Microchip, here are the critical specs for troubleshooting:
| Parameter | Value | |--------------------|---------------------------------| | Supply voltage | 3.3V ± 5% | | Standby current | ~50 µA | | Active current | 15–25 mA (depending on clock) | | LPC clock | 33 MHz | | Package | 128-LQFP (14x14mm, 0.4mm pitch) | | ADC inputs | 8 channels, 10-bit | | PWM outputs | 4 (fan, backlight, etc.) |
| Device | Base I/O | IRQ | DMA | |--------|----------|-----|-----| | Floppy | 3F0h/370h | 6 | 2 | | Parallel | 378h/278h | 7 | 3 (ECP) | | UART A | 3F8h | 4 | - | | UART B | 2F8h | 3 | - | | KBC (keyboard) | 60h/64h | 1 | - | | KBC (mouse) | 60h/64h | 12 | - | | HWM | 290h (typical) | - | - |
| Parameter | Value | | :--- | :--- | | Supply Voltage | 3.3V (±5%) | | I/O Tolerance | 5V tolerant (LPC pins) | | Internal Oscillator | 48 MHz (PLL derived) | | Flash Memory | 128 KB (Embedded) | | RAM | 4 KB | | Package | TQFP-128 (14x14 mm) | | Operating Temp | 0°C to +85°C (Commercial) | | Thermal Resistance (ΘJA) | 45°C/W |
Why the "Hot" Warning? The datasheet reveals that the KBC1126NU can draw up to 250mA during heavy LPC traffic. In standby, it draws 10mA. However, a common failure mode is the chip running scorchingly hot (>85°C) due to:
VCC_RTC rail.VSTBY (Standby voltage) line.If your chip is physically hot to the touch without the laptop turning on, suspect a internal die short (requires replacement).
The Low Pin Count bus is where heat builds up.
Datasheet Note: These pins have a maximum toggle frequency of 33 MHz. Continuous high-speed communication with the PCH (Platform Controller Hub) raises chip temperature by 10-15°C. Keyboard Controller : Supports up to 120 keys,
"Hot" Hacking Tip: You can rewrite the EC firmware via the LPC bus using flashrom under Linux, but only if the datasheet's "Host Interface" register (0x60/0x64) is unlocked. Without the datasheet, you will brick the device.