Microchip Technology SIO1028I-JZX-TR

Overview

SIO1028I-JZX-TR from Microchip Technology is a 3.3V LPC Super I/O controller with 5V-tolerant I/O, PC99/PC01 and ACPI 1.0 compliance, supporting 19.2–33 MHz LPC bus frequencies, three NS16C550A-compatible UARTs (including IrDA v1.2 Fast IR on UART2), and 24 GPIO pins. It serves as the primary legacy I/O hub in space-constrained notebook and embedded x86 designs requiring serial, infrared, LED control, and watchdog functionality.

For engineers reviewing the SIO1028I-JZX-TR datasheet, SIO1028I-JZX-TR pinout, SIO1028I-JZX-TR application, or SIO1028I-JZX-TR equivalent, key selection criteria include LPC interface timing compliance, UART FIFO depth (16-byte), IrDA v1.2 support on UART2, GPIO count (24), and QFN-64 package thermal and routing constraints.

Technical Context

The SIO1028I-JZX-TR integrates an LPC bus interface with Serial IRQ and CLKRUN# support, enabling direct connection to Intel/AMD southbridge chipsets without translation logic. Its internal configuration registers map GPIO, UART, IR, and LED functions to dedicated multifunction pins under ACPI-compliant power management control.

UART2 implements dual-mode operation: standard 16C550A serial mode and IrDA v1.2 Fast IR (4 Mbps) with separate IRTX2/IRRX2 pins and IRMODE# control. The device uses a single 32.768 kHz clock input (CLKI32) for baud rate generation and watchdog timing, eliminating external crystal requirements for basic operation.

Key Specifications

Pinout & Package

64-pin QFN package with 9 × 9 mm body, 0.5 mm pitch, and exposed thermal pad (VSS-connected). RoHS compliant per Microchip specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCT6776D and IT8786E, the SIO1028I-JZX-TR uniquely delivers IrDA v1.2 Fast IR in a 64-pin QFN at 33 MHz LPC speed - making it the only option for space-constrained, infrared-enabled x86 embedded designs requiring full ACPI 1.0 compliance.

Availability

SIO1028I-JZX-TR is available at Aetrix Electronics and suitable for industrial thin clients, medical diagnostic terminals, embedded point-of-sale systems, and automated test equipment controllers requiring stable component supply and long-term lifecycle support.

Supply support for SIO1028I-JZX-TR 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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and interface ICs, with global design, manufacturing, and support infrastructure.

The SIO1028 product line targets advanced notebook and embedded x86 platforms needing integrated legacy I/O - designed specifically to replace discrete UART, IR, GPIO, and watchdog functions in LPC-based architectures.

FAQ

What is the maximum supported LPC bus frequency for the SIO1028I-JZX-TR?

The SIO1028I-JZX-TR supports LPC bus frequencies from 19.2 MHz up to 33 MHz, as confirmed in the DS00001818A datasheet Section "LPC Interface". This range ensures compatibility with Intel ICH7–ICH10 and AMD SB600–SB800 southbridge chipsets. Operation above 33 MHz is not supported and may cause configuration register access failures or UART timing errors in the SIO1028I-JZX-TR.

Does the SIO1028I-JZX-TR support IrDA v1.2 Fast IR on all three UARTs?

No - IrDA v1.2 Fast IR (4 Mbps) is supported exclusively on UART2 of the SIO1028I-JZX-TR, as documented in the "Infrared Communications Controller" section of DS00001818A. UART1 and UART3 operate in standard NS16C550A mode only. UART2 requires IRTX2/IRRX2 pins and IRMODE# control to activate infrared mode, and does not support IrDA on other serial ports.

How many GPIO pins does the SIO1028I-JZX-TR provide, and are they 5V tolerant?

The SIO1028I-JZX-TR provides exactly 24 general-purpose I/O pins, as specified in both the Product Features and Description sections of DS00001818A. All GPIOs are 5V tolerant when operated at 3.3V supply, consistent with the device's overall 5V-tolerant I/O architecture. This tolerance applies to GP[11:13]*, GP16, GP[20:23]*, GP[30:37]*, and GP[50:57]* pin groups in the SIO1028I-JZX-TR.

Is an external crystal required for the SIO1028I-JZX-TR to operate its UARTs and watchdog timer?

No external crystal is required for basic UART or watchdog operation in the SIO1028I-JZX-TR. The device accepts a single 32.768 kHz clock input (CLKI32) to drive the programmable baud rate generator and watchdog timer, as shown in the Block Diagram (DS00001818A, page 3). While higher-accuracy timing can be achieved with a 1–48 MHz crystal on CLKI, the 32.768 kHz source suffices for 230/460 kbps UART rates and typical WDT timeouts.

What package type and RoHS status does the SIO1028I-JZX-TR use?

The SIO1028I-JZX-TR uses a 64-pin QFN package with 9 × 9 mm body and 0.5 mm pitch, as defined in the "PACKAGE OUTLINE" section (DS00001818A, pages 4–5). It is RoHS compliant per Microchip's packaging specification, with halogen content meeting IEC61249-2-21 limits. The "JZX" suffix explicitly denotes this QFN variant, and "-TR" indicates tape-and-reel packaging for automated assembly - both confirmed in the Product Identification System (DS00001818A, page 8).