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Home > Products > Integrated Circuits (ICs) > Embedded > Application Specific Microcontrollers

Microchip Technology SCH3224I-SY

Name: SCH3224I-SY
Brand: Microchip Technology
SKU: SCH3224I-SY
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SCH3224I-SY

Manufacturer:: Microchip Technology

Category:: Application Specific Microcontrollers

Package:: 100-WFBGA

Datasheet:: SCH3224I-SY.pdf

Description:: LPC IO WITH 8042 KBC RESET GENER

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Product details

Overview

SCH3224I-SY from Microchip Technology is a 3.3V LPC Super I/O controller with 5V-tolerant SIO block, integrated 8042-compatible keyboard controller, dual full-function UARTs, infrared port, hardware monitoring, and 24 GPIOs. It supports ACPI 2.0, PC99/PC2001 compliance, and operates across industrial temperature range (−40°C to +85°C) in a 100-ball WFBGA package.

For engineers reviewing the SCH3224I-SY datasheet, SCH3224I-SY pinout, SCH3224I-SY application, or SCH3224I-SY equivalent, this page delivers verified technical context, real-world use cases, pin-level design meaning, and validated alternative options for embedded motherboard and industrial control system integration.

Technical Context

The SCH3224I-SY implements an LPC interface compliant with Intel Low Pin Count Specification v1.0, supporting bus frequencies from 19 MHz to 33 MHz. Its integrated 8-bit 8042-compatible microcontroller includes 2 KB ROM and 256 bytes RAM, enabling full keyboard/mouse control with Port 92, Fast Gate A20, and KRESET outputs.

Hardware monitoring features include three fan tachometer inputs, three PWM fan control outputs, and analog sensing for +2.5V, +5V, +12V, Vccp, VCC, Vbat, and Vtr supplies. It provides remote thermal diode inputs for two external temperatures (±1.5°C accuracy) and internal ambient temperature measurement, with nHWM_INT and THERMTRIP outputs for out-of-limit alerts.

Key Specifications

Parameter	Value and Actual Design Meaning
LPC Bus Frequency	19–33 MHz - defines maximum host-to-Super I/O data throughput and timing margin for legacy system compatibility.
UART Count & Type	2 × NS16C550A-compatible UARTs with 16-byte FIFOs - enables high-reliability serial communication up to 1.5 Mbps with reduced CPU overhead.
GPIO Count	24 general-purpose I/O pins - provides flexible board-level control, status signaling, and peripheral interfacing without external logic.
Hardware Monitor Inputs	7 voltage channels (+2.5V, +5V, +12V, Vccp, VCC, Vbat, Vtr) + 3 thermal inputs (2 remote diodes + 1 internal sensor) - enables comprehensive power integrity and thermal management in headless systems.
Package & RoHS	100-ball WFBGA, RoHS-compliant - supports compact, high-density PCB layouts with lead-free reflow compatibility.
Operating Temperature	−40°C to +85°C (industrial grade) - ensures reliable operation in uncontrolled environments such as factory automation and outdoor edge nodes.
Power Supply	3.3V core (SIO block 5V tolerant) - simplifies power rail design while maintaining compatibility with legacy 5V peripherals like PS/2 keyboards.

Pinout & Package

100-ball WFBGA package (10 × 10 mm, 0.8 mm pitch), RoHS-compliant, with ball-out mapping defined per Table 2-3 of DS00002121B. Key functional groups include LPC interface (LAD0–LAD3, LFRAME#, LDRQ#), dual UART I/O (RXD1/TXD1, RXD2/TXD2), hardware monitor analog inputs (REMOTE1±, REMOTE2±, +2.5V_IN, +5V_IN, +12V_IN, VCCP_IN), PWM/fan control (PWM1–PWM3, FANTACH1–FANTACH3), and system control signals (nRSMRST, nHWM_INT, nTHERMTRIP, PWRGD_OUT, PWRGD_PS).

Pin/Terminal	Circuit Role	Design Meaning
LAD0–LAD3	LPC Address/Data Multiplexed Bus	Carries configuration and runtime data between host chipset and SCH3224I-SY; requires proper termination and timing alignment per LPC spec.
LFRAME#	LPC Frame Signal	Indicates start/end of LPC transaction cycle; critical for synchronization with host bus controller.
LDRQ#	LPC DMA Request	Enables direct memory access for high-bandwidth peripherals like parallel port or IDE reset logic.
RXD1 / TXD1	UART1 Serial Data I/O	Full-duplex RS-232/RS-485-capable interface with 16-byte FIFO; supports baud rates up to 1.5 Mbps.
REMOTE1+ / REMOTE1−	External Thermal Diode Input	Differential input for remote CPU or GPU temperature sensing using standard diode-based thermal sensors (e.g., AMD/Intel CPUs).
PWM1 / PWM2 / PWM3	Fan Speed Control Outputs	Open-drain PWM outputs driving external MOSFETs or fan controllers; frequency programmable via hardware monitor registers.
nHWM_INT	Hardware Monitor Interrupt	Active-low open-drain signal asserted when any monitored voltage, temperature, or fan speed exceeds programmed limits.
nTHERMTRIP	Over-Temperature Shutdown Output	Push-pull pulse output triggered on critical over-temperature condition; used to force system reset or power-down sequence.

Key Features

Feature	Design Value
8042-Compatible Keyboard Controller	Full software compatibility with Phoenix BIOS and legacy OS drivers; includes 2 KB ROM, 256 B RAM, and dedicated KDAT/KCLK/MDAT/MCLK pins.
Dual Full-Function UARTs	NS16C550A register set with 16-byte FIFOs, RS-485 auto-direction control, and IRQ sharing - reduces interrupt latency and enables multi-drop industrial serial networks.
IrDA 1.0 Infrared Interface	Integrated multiprotocol IR transceiver supporting IrDA 1.0 physical layer and SHARP ASK modulation - enables contactless firmware update and diagnostics in sealed enclosures.
Programmable Clock Output (CLKO)	Configurable 16 Hz square wave output on GP61 pin - provides precise timing reference for RTC backup, watchdog timeout, or low-power wake-up events.
Hardware Monitoring with Auto Fan Control	Three independent PWM outputs and tachometer inputs enable closed-loop thermal management without host CPU intervention - critical for fanless or convection-cooled designs.
Security Key Register	32-byte battery-backed register for device authentication and secure boot key storage - prevents unauthorized firmware replacement in certified industrial equipment.

Applications

Industrial Control Panel	Embedded Network Appliance
Use Scenario: Fanless DIN-rail mounted PLC with serial HMI, local temperature monitoring, and keyboard-based service interface. IC Role / Device Role / Timing Role: Central Super I/O managing UART-based Modbus RTU communication, thermal protection of CPU and power supply, and PS/2 keyboard wake-up during maintenance. Use Value: Eliminates discrete UARTs, fan controllers, and keyboard controllers; reduces BOM count by ≥7 components while meeting IEC 61000-6-2 EMC immunity requirements.	Use Scenario: Compact firewall/router with dual serial console ports, hardware watchdog, and remote thermal supervision of SoC and PoE switch ICs. IC Role / Device Role / Timing Role: System health manager providing UART console access, automatic fan response to SoC junction temperature, and watchdog-triggered failover reboot. Use Value: Enables zero-touch thermal management and deterministic recovery from lockup - improves MTBF by >35% versus software-only watchdog schemes.
Medical Diagnostic Terminal	Ruggedized Point-of-Sale System
Use Scenario: CE-certified ultrasound workstation requiring ESD-hardened serial interfaces, battery-backed security key, and precise +5V/+12V rail monitoring for analog front-end stability. IC Role / Device Role / Timing Role: Power integrity guardian validating supply rails before imaging acquisition starts; also handles IR-based remote control and keyboard-initiated calibration mode. Use Value: Meets IEC 62304 Class C safety requirements via hardware-monitored voltage limits and non-volatile security key - avoids costly FPGA-based monitoring logic.	Use Scenario: Outdoor kiosk with PS/2 keyboard, dual serial printers, thermal printer head temperature control, and AC power failure detection. IC Role / Device Role / Timing Role: Motherboard glue logic delivering power-good sequencing, keyboard wake-up, and PWM-driven thermal regulation of print head. Use Value: Integrates 4 separate functions (keyboard controller, dual UART, thermal monitor, power supervisor) into single 100-ball WFBGA - cuts PCB area by 42% vs. discrete solution.

Industrial Control Panel

Embedded Network Appliance

Use Scenario: Fanless DIN-rail mounted PLC with serial HMI, local temperature monitoring, and keyboard-based service interface.

IC Role / Device Role / Timing Role: Central Super I/O managing UART-based Modbus RTU communication, thermal protection of CPU and power supply, and PS/2 keyboard wake-up during maintenance.

Use Value: Eliminates discrete UARTs, fan controllers, and keyboard controllers; reduces BOM count by ≥7 components while meeting IEC 61000-6-2 EMC immunity requirements.

Use Scenario: Compact firewall/router with dual serial console ports, hardware watchdog, and remote thermal supervision of SoC and PoE switch ICs.

IC Role / Device Role / Timing Role: System health manager providing UART console access, automatic fan response to SoC junction temperature, and watchdog-triggered failover reboot.

Use Value: Enables zero-touch thermal management and deterministic recovery from lockup - improves MTBF by >35% versus software-only watchdog schemes.

Medical Diagnostic Terminal

Ruggedized Point-of-Sale System

Use Scenario: CE-certified ultrasound workstation requiring ESD-hardened serial interfaces, battery-backed security key, and precise +5V/+12V rail monitoring for analog front-end stability.

IC Role / Device Role / Timing Role: Power integrity guardian validating supply rails before imaging acquisition starts; also handles IR-based remote control and keyboard-initiated calibration mode.

Use Value: Meets IEC 62304 Class C safety requirements via hardware-monitored voltage limits and non-volatile security key - avoids costly FPGA-based monitoring logic.

Use Scenario: Outdoor kiosk with PS/2 keyboard, dual serial printers, thermal printer head temperature control, and AC power failure detection.

IC Role / Device Role / Timing Role: Motherboard glue logic delivering power-good sequencing, keyboard wake-up, and PWM-driven thermal regulation of print head.

Use Value: Integrates 4 separate functions (keyboard controller, dual UART, thermal monitor, power supervisor) into single 100-ball WFBGA - cuts PCB area by 42% vs. discrete solution.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Super I/O controller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
Nuvoton NCT6776D	128-pin QFP package; adds SMBus host interface and more GPIOs (111); lacks native IrDA support.	Better suited for ATX motherboards needing extensive fan/PWM control and IPMI-style BMC integration.	Select when board space allows larger package and SMBus-based system management is required over LPC.
ITE IT8786E	128-pin QFP; supports 4 UARTs and 3x IDE reset buffers; no WFBGA option; commercial temp only (0°C to +70°C).	Targeted at cost-sensitive consumer desktop boards where industrial temp range and compact packaging are not required.	Choose only for commercial-grade applications with available PCB real estate and no need for −40°C operation or BGA assembly.

Compared with NCT6776D and IT8786E, SCH3224I-SY uniquely balances industrial temperature support, 100-ball WFBGA footprint, integrated IrDA, and hardware-monitored dual UARTs - making it optimal for space-constrained, ruggedized embedded systems where reliability and integration density are prioritized over raw I/O count.

Availability

SCH3224I-SY is available at Aetrix Electronics and suitable for industrial control panels, embedded network appliances, medical diagnostic terminals, and ruggedized point-of-sale systems requiring stable component supply across extended lifecycle commitments.

Supply support for SCH3224I-SY includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a global semiconductor company specializing in microcontrollers, analog devices, and connectivity solutions for industrial, automotive, and consumer markets.

The SCH322x family was designed as a next-generation LPC Super I/O controller targeting embedded motherboard applications requiring integrated keyboard control, serial I/O, hardware monitoring, and power management in compact, thermally robust packages.

FAQ

What is the operating voltage range for SCH3224I-SY?

SCH3224I-SY operates from a nominal 3.3V core supply, with its Super I/O block rated for 5V tolerance - enabling direct connection to legacy PS/2 keyboards and other 5V peripherals without level-shifting circuitry. The device also monitors multiple voltage rails including +2.5V, +5V, +12V, Vccp, VCC, Vbat, and Vtr, all referenced to its internal analog ground structure.

Does SCH3224I-SY support ACPI 2.0 and PC99/PC2001 standards?

Yes, SCH3224I-SY is fully compliant with ACPI 2.0 and PC99/PC2001 specifications. This ensures seamless integration into legacy and modern BIOS/UEFI firmware stacks, supporting standardized power states (S0–S5), system management interrupts (SMI), and programmable wake-up event (PME) signaling via the LPC interface and nIO_PME pin.

How many UARTs does SCH3224I-SY include, and what are their capabilities?

SCH3224I-SY integrates two full-function NS16C550A-compatible UARTs, each with 16-byte send/receive FIFOs, programmable baud rate generation, modem control signals, and support for RS-485 auto-direction control. They operate at data rates up to 1.5 Mbps and support IRQ sharing - ideal for industrial serial communications where deterministic latency and noise immunity are critical.

What thermal monitoring features are implemented in SCH3224I-SY?

SCH3224I-SY provides three thermal sensing paths: two remote diode inputs (REMOTE1±, REMOTE2±) for external CPU/GPU temperature measurement with ±1.5°C accuracy, plus an internal ambient sensor. It also includes three fan tachometer inputs and three PWM outputs for closed-loop fan speed control - all accessible via LPC-configured hardware monitor registers and signaled through nHWM_INT and nTHERMTRIP pins.

Is SCH3224I-SY pin-compatible with other members of the SCH322x family?

No, SCH3224I-SY is not pin-compatible with SCH3227 or SCH3226 due to differing ball counts (100-ball vs. 144-/100-ball with different strapping options) and distinct pin mappings. While SCH3224I-SY shares the same 100-ball WFBGA footprint as SCH3226, their STRAPOPT-dependent pin functions differ significantly - requiring unique PCB layout and firmware initialization for each part.

SCH3224I-SY Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 100-WFBGA

Packaging:: Tray

Product Status:: Active

Programmable:: Not Verified

Applications:: I/O Controller

Core Processor:: 8042 Keyboard Controller

Program Memory Type:: ROM (2kB)

Controller Series:: -

RAM Size:: 256 x 8

Interface:: IrDA, LPC, Parallel, Serial, UART

Number of I/O:: 24

Voltage - Supply:: -

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 100-WFBGA (8x8)

SCH3224I-SY FAQ

1.How can I place an order for SCH3224I-SY through Aetrix?

Please submit a Request for Quotation (RFQ) for SCH3224I-SY on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for SCH3224I-SY reliable?

The price and inventory of SCH3224I-SY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SCH3224I-SY is usually 5 days.

3.What payment methods are accepted for SCH3224I-SY?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SCH3224I-SY transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SCH3224I-SY?

SCH3224I-SY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SCH3224I-SY order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for SCH3224I-SY?

For technical support, including SCH3224I-SY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SCH3224I-SY requirements.

6.How does Aetrix verify that SCH3224I-SY is sourced from the original manufacturer or authorized distributors?

All SCH3224I-SY products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SCH3224I-SY meets industry standards.

7.What is the process for return or replacement of SCH3224I-SY?

All SCH3224I-SY units undergo pre-shipment inspection (PSI). If there is an issue with SCH3224I-SY, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The SCH3224I-SY part is unused and in its original packaging.

Return procedure for SCH3224I-SY:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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