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Microchip Technology SCH3227I-SZ
- Part No.:
- SCH3227I-SZ
- Manufacturer:
- Microchip Technology
- Category:
- Application Specific Microcontrollers
- Package:
- 144-WFBGA
- Datasheet:
-
SCH3227I-SZ.pdf
- Description:
- LPC IO WITH 8042 KBC RESET GENER
- Quantity:
- Payment:
- Shipping:
Inventory:2,416
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Product details
Overview
SCH3227I-SZ from Microchip Technology is a 3.3V LPC Super I/O controller with 5V-tolerant SIO block, supporting PC99/PC2001 and ACPI 2.0 compliance. It integrates an 8042-compatible keyboard controller, four full NS16C550A UARTs (1.5 Mbps, 16-byte FIFO), hardware monitoring (voltage, temperature, fan control), and a 144-ball WFBGA package for industrial motherboards.
For engineers reviewing the SCH3227I-SZ datasheet, SCH3227I-SZ pinout, SCH3227I-SZ application, or SCH3227I-SZ equivalent, this page delivers verified technical context, strap-dependent pin functions, hardware monitor register access via LPC, and validated alternatives for legacy PC platform design continuity.
Technical Context
The SCH3227I-SZ implements a Low Pin Count (LPC) bus interface compliant with Intel LPC Specification Rev 1.0, operating at 19–33 MHz. Its 8042 keyboard controller includes 2 kB ROM and 256 B RAM, supports Port 92, Fast Gate A20, and KRESET outputs, and provides asynchronous access to status/data registers with IRQ/polling modes.
Hardware monitoring features include three analog voltage inputs (+2.5V, +5V, +12V), Vccp/VCC/Vbat/VTR sensing, dual thermal diode inputs (±1.5°C accuracy), internal ambient sensor, programmable fan PWM outputs (PWM1–PWM3), and nHWM_INT/THERMTRIP interrupt signaling - all accessible via LPC-configurable registers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LPC Bus Frequency | 19–33 MHz; enables direct CPU-to-Super I/O communication without ISA bridge latency |
| UART Count & Type | 4 × full NS16C550A-compatible UARTs; each with 16-byte TX/RX FIFO and RS485 auto-direction control |
| Max UART Baud Rate | 1.5 Mbps; supports high-speed serial peripherals like industrial modems and barcode scanners |
| Hardware Monitor Inputs | +2.5V, +5V, +12V, Vccp, VCC, Vbat, VTR, and two external thermal diodes; enables full motherboard power rail health tracking |
| GPIO Count | 40 pins; includes 6 VID-compatible inputs for processor voltage identification in desktop/server platforms |
| Package | 144-ball WFBGA; RoHS-compliant, industrial-grade (-40°C to +85°C) footprint for compact PCB layout |
| Strap Option | STRAPOPT pin selects between SCH3114/SCH3116 legacy device ID (0x7F/0x7D); determines GPIO mapping and feature enablement |
Pinout & Package
Package: 144-ball WFBGA (RoHS-compliant), industrial temperature range (-40°C to +85°C). Ball pitch: 0.5 mm. Dimensions: 10 mm × 10 mm × 1.0 mm (max height).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| K13 | STRAPOPT | Selects legacy device ID (0x7F = VTR, 0x7D = VSS) and configures GPIO/function mapping per Table 2-1 |
| J1–J2 | nIDE_RSTDRV / nPCIRST[1–3] | Strap-selectable IDE reset or PCI reset buffer outputs; software-controllable for system-level reset sequencing |
| A5 | nHWM_INT | Open-drain interrupt output asserting on out-of-limit voltage, temperature, or fan speed conditions |
| B6 | nTHERMTRIP | Dedicated over-temperature pulse output; triggers system shutdown/reset independent of firmware |
| A4–C4 | REMOTE1± / REMOTE2± | Dual thermal diode input pairs; support remote CPU/die and chipset temperature sensing with ±1.5°C accuracy |
| A1–A2, B1–B2 | +2.5V_IN / +12V_IN / +5V_IN | Analog power supply inputs for hardware monitor ADC; require local decoupling per datasheet layout guidelines |
Key Features
| Feature | Design Value |
|---|---|
| 8042 Keyboard Controller | Full Phoenix BIOS ROM compatibility, Port 92 support, and Fast Gate A20/KRESET outputs enable plug-and-play PS/2 keyboard/mouse integration |
| Hardware Monitor | Programmable fan PWM outputs (PWM1–PWM3) with automatic thermal response; eliminates need for external fan controllers in embedded systems |
| Serial Port Flexibility | Four full UARTs plus two strap-selectable 4-pin UARTs; supports mixed legacy (RS232) and modern (RS485) serial topologies on single chip |
| Security Key Register | 32-byte battery-backed register for device authentication; retains values during AC loss, enabling secure boot chain validation |
| LPC Interface | Direct connection to PCH/CPU without ISA bridge; reduces BOM count and improves power management responsiveness in modern x86 platforms |
Applications
| Desktop Motherboard Power Management | Industrial Embedded Control Panel |
|---|---|
Use Scenario: ATX motherboard implementing ACPI S3/S4 sleep states with wake-on-keyboard, wake-on-serial, and thermal throttling. IC Role / Device Role / Timing Role: Central Super I/O managing keyboard controller, LPC-based hardware monitoring, and system reset generation. Use Value: Integrates 4 UARTs, parallel port, IR, and fan control - reducing discrete logic count by ≥7 components versus legacy ISA-based designs. |
Use Scenario: DIN-rail mounted PLC HMI with RS485 Modbus RTU interface, local temperature monitoring, and watchdog-triggered safe shutdown. IC Role / Device Role / Timing Role: System-level I/O hub providing isolated serial communication, analog voltage supervision, and thermal safety interlock. Use Value: Dual thermal diode inputs and nTHERMTRIP output enable hardware-enforced thermal cutoff without host CPU intervention. |
| Legacy PC Platform Replacement | Server Baseboard Management |
Use Scenario: Migration from SCH311x-family Super I/O to newer microarchitecture with LPC-only chipset support. IC Role / Device Role / Timing Role: Drop-in functional replacement with identical register map and strap-driven legacy mode selection. Use Value: STRAPOPT pin allows seamless transition: set to VTR for SCH3114 emulation or VSS for SCH3116 behavior - preserving BIOS compatibility. |
Use Scenario: 1U server baseboard requiring remote voltage telemetry (+12V/+5V/Vccp), fan speed feedback, and IPMI-over-serial console access. IC Role / Device Role / Timing Role: BMC-adjacent Super I/O providing hardware-monitored power rails and dual UARTs for console + service processor communication. Use Value: Four full UARTs support simultaneous console, BMC debug, and out-of-band management ports - eliminating need for external UART expanders. |
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 |
|---|---|---|---|
| IT8786E-S | 128-pin QFP; lacks IDE/PCI reset buffers and strap-selectable UART configuration; supports only 2 full UARTs | Targeted at cost-sensitive consumer boards without industrial thermal/fan requirements | Choose when board space permits QFP and hardware monitor depth is secondary to BOM cost |
| NCT6776D | 128-pin QFP; adds SMBus/I²C interface and enhanced fan curve programming; no native LPC Serial IRQ support | Preferred for modern UEFI platforms requiring dynamic fan control and sensor polling via SMBus | Choose when migrating to SMBus-based BMC architecture and legacy Serial IRQ is not required |
Compared with IT8786E-S and NCT6776D, the SCH3227I-SZ uniquely combines strap-configurable reset outputs, 4 full UARTs with RS485 mode, and dual thermal diode support in a 144-ball WFBGA - making it optimal for space-constrained industrial motherboards needing legacy compatibility and hardware-enforced thermal safety.
Availability
SCH3227I-SZ is available at Aetrix Electronics and suitable for desktop motherboard design, industrial control panel integration, legacy PC platform replacement, and server baseboard management requiring stable component supply across extended product lifecycles.
Supply support for SCH3227I-SZ 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 computing markets.
The SCH3227I-SZ belongs to Microchip's LPC Super I/O product line, designed specifically to replace legacy ISA-based Super I/O chips in x86 platforms while maintaining full ACPI, PC99, and BIOS compatibility.
FAQ
What is the operating voltage range for the SCH3227I-SZ?
The SCH3227I-SZ operates at 3.3V nominal core voltage, with its Super I/O block rated for 5V tolerance. Analog inputs (+2.5V_IN, +5V_IN, +12V_IN) accept corresponding rail voltages directly. The device supports industrial temperature range (-40°C to +85°C), and all voltage specifications are defined in DS00002121B Section 4.0. SCH3227I-SZ requires proper decoupling per Microchip's layout recommendations to maintain stability under dynamic load conditions.
How does the STRAPOPT pin affect SCH3227I-SZ functionality?
The STRAPOPT pin on SCH3227I-SZ determines both device identification and peripheral mapping: when tied to VTR, it reports Device ID 0x7F and enables SCH3114-compatible GPIO functions; when tied to VSS, it reports Device ID 0x7D and enables SCH3116 mode. This selection also controls whether IDE reset or PCI reset signals appear on pins J1–L3. SCH3227I-SZ must be configured at power-on, and the strap state cannot be changed dynamically in operation.
Does the SCH3227I-SZ support hardware-based thermal shutdown?
Yes, the SCH3227I-SZ provides dedicated hardware thermal protection via the nTHERMTRIP output pin, which asserts a pulse signal upon exceeding a programmable temperature threshold - independent of host firmware or OS. This signal can directly drive a system reset or power-off circuit. SCH3227I-SZ supports two external thermal diode inputs (REMOTE1±, REMOTE2±) with ±1.5°C accuracy, plus internal ambient sensing, all monitored in real time by on-die comparators.
Can the SCH3227I-SZ replace older Super I/O chips like the SCH3114?
Yes, the SCH3227I-SZ is explicitly designed as a next-generation replacement for the SCH311x family. When STRAPOPT is strapped to VTR, SCH3227I-SZ emulates SCH3114 register behavior and pin functions. Microchip confirms functional equivalence for keyboard controller, UARTs, hardware monitor, and LPC interface - enabling BIOS reuse and minimizing board redesign effort. SCH3227I-SZ retains full PC99/ACPI 2.0 compliance required for modern platform certification.
What serial communication protocols does the SCH3227I-SZ support?
The SCH3227I-SZ supports RS232 (via full 8-pin UARTs), RS485 (with auto-direction control enabled per UART), IrDA 1.0 infrared, and SHARP ASK IR protocols. Its four NS16C550A-compatible UARTs operate up to 1.5 Mbps with 16-byte FIFOs, and two additional 4-pin UARTs are available via strap option. SCH3227I-SZ also includes modem control circuitry (nRTS/nCTS/nDSR/nDCD) and supports IRQ sharing across serial ports for efficient interrupt handling.
SCH3227I-SZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 144-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:
- 40
- Voltage - Supply:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 144-WFBGA (9x9)
SCH3227I-SZ FAQ
1.How can I place an order for SCH3227I-SZ through Aetrix?
Please submit a Request for Quotation (RFQ) for SCH3227I-SZ 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 SCH3227I-SZ reliable?
The price and inventory of SCH3227I-SZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SCH3227I-SZ is usually 5 days.
3.What payment methods are accepted for SCH3227I-SZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SCH3227I-SZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SCH3227I-SZ?
SCH3227I-SZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SCH3227I-SZ 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 SCH3227I-SZ?
For technical support, including SCH3227I-SZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SCH3227I-SZ requirements.
6.How does Aetrix verify that SCH3227I-SZ is sourced from the original manufacturer or authorized distributors?
All SCH3227I-SZ 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 SCH3227I-SZ meets industry standards.
7.What is the process for return or replacement of SCH3227I-SZ?
All SCH3227I-SZ units undergo pre-shipment inspection (PSI). If there is an issue with SCH3227I-SZ, 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 SCH3227I-SZ part is unused and in its original packaging.
Return procedure for SCH3227I-SZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SCH3227I-SZ Tags
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