Infineon Technologies SL811HST-AXC

Overview

SL811HST-AXC from Infineon Technologies (formerly Cypress Semiconductor) is an embedded USB 1.1 host/slave controller with integrated SIE, transceivers, and 256-byte SRAM. It supports full-speed (12 Mbps) and low-speed (1.5 Mbps) operation in either mode, features an 8-bit microprocessor bus interface with DMA support in slave mode, and operates from a 12 MHz or 48 MHz crystal via built-in DPLL. It is used in industrial USB peripherals such as barcode scanners and embedded HIDs.

For engineers reviewing the SL811HST-AXC datasheet, SL811HST-AXC pinout, SL811HST-AXC application, or SL811HST-AXC equivalent, key selection criteria include dual-mode USB 1.1 compliance, 5 V-tolerant I/O, 3.3 V supply, TQFP-48 packaging, and on-chip root hub functionality - all critical for legacy USB peripheral integration in resource-constrained embedded systems.

Technical Context

The SL811HST-AXC implements a hardware Serial Interface Engine (SIE) compliant with USB Specification 1.1, eliminating software-based protocol handling. Its dual-role architecture allows runtime switching between host and peripheral modes under software control, with automatic speed detection (1.5/12 Mbps) and SOF/CRC5/16 generation handled autonomously.

It integrates USB transceivers, PLL-based clock generation (12/48 MHz input), and a 256-byte RAM buffer partitioned dynamically: 16 bytes for control registers + 240 bytes for data in host mode; 64 bytes for endpoint registers + 192 bytes for buffers in slave mode. Auto-address increment mode reduces memory access overhead during bulk transfers.

Key Specifications

Pinout & Package

SL811HST-AXC is housed in a 48-pin Thin Quad Flat Package (TQFP) with 0.5 mm pitch, optimized for compact PCB layouts and thermal performance in embedded applications. Pin functions are validated per Cypress/Infineon Document Number 38-08008 Rev. *J.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB host/peripheral controller applications.

Compared with ISP1301 and MAX3421E, SL811HST-AXC uniquely delivers integrated SIE, dual-role operation, and 8-bit bus compatibility in one package - making it irreplaceable for cost-sensitive, microcontroller-agnostic USB peripheral or host implementations requiring minimal firmware overhead.

Availability

SL811HST-AXC is available at Aetrix Electronics and suitable for industrial barcode scanners, embedded USB HID devices, and USB host interfaces for flash storage requiring stable component supply, long-term lifecycle support, and legacy USB 1.1 compatibility.

Supply support for SL811HST-AXC 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

Infineon Technologies acquired Cypress Semiconductor in 2020 and maintains the SL811HST-AXC as part of its embedded connectivity portfolio, delivering high-reliability semiconductor solutions for industrial and automotive markets.

This device belongs to Cypress's legacy USB connectivity product line, designed specifically for resource-constrained embedded systems needing plug-and-play USB host or peripheral functionality without software USB stack dependency.

FAQ

Does SL811HST-AXC support USB 2.0?

No. SL811HST-AXC complies strictly with USB Specification 1.1 and supports only full-speed (12 Mbps) and low-speed (1.5 Mbps) modes. It does not implement high-speed (480 Mbps) signaling, transaction translators, or USB 2.0 hub features. Designs requiring USB 2.0 must use alternative controllers such as the MAX3421E or integrated MCU solutions.

Can SL811HST-AXC operate as both host and peripheral simultaneously?

No. The device operates exclusively in one mode at a time - either host or peripheral - selected via software configuration. Simultaneous dual-role operation (e.g., acting as host to one device while being a peripheral to another) is not supported. Mode switching requires full reinitialization of USB state machines and memory mapping.

Is the DMA interface reliable in slave mode?

Per Cypress/Infineon Errata (page 33, Rev. *J), the DMA interface in slave mode is subject to unreliability under certain timing conditions. Recommended practice is to use programmed I/O for critical transfers; DMA may be employed only after thorough validation in the target system with appropriate hold-time margins and noise mitigation.

What crystal specifications are mandatory for stable 48 MHz operation?

A 48 MHz third-overtone crystal with ≤40 Ω ESR, 10 pF minimum load capacitance, ±100 ppm frequency tolerance, and 0 °C to 70 °C operating range is required. The CM pin must be tied to GND, and an external Cin/Lin filter (22 pF / 2.2 µH) is mandatory to suppress fundamental-mode resonance and ensure clean 48 MHz clock synthesis.