Infineon Technologies CYAC1126-40LQXIT

Overview

CYAC1126-40LQXIT from Infineon is a single-port USB Type-C port controller with integrated Arm® Cortex®-M0 MCU (16 MHz, 16 KB flash, 4 KB SRAM), USB Type-C v1.3 PHY, dual VCONN FETs (1.0 W max), and a 5 V/3 A high-side VBUS load switch (R_DS(on) = 45 mΩ typ) in 40-QFN package. It supports BC v1.2 charge detection, UVP/OVP/RCP/SCP thermal shutdown, and high-side current sensing via external 5 mΩ sense resistor - deployed in notebook/desktop Type-A-to-Type-C conversion modules.

For engineers reviewing the CYAC1126-40LQXIT datasheet, CYAC1126-40LQXIT pinout, CYAC1126-40LQXIT application, or CYAC1126-40LQXIT equivalent, key selection criteria include VBUS load switch specs (5 V/3 A, 45 mΩ), integrated VCONN power delivery (CC1/CC2, 1.0 W), UCSI-compatible I²C interface, BC v1.2 charge detect, and industrial temperature range (–40°C to +85°C).

Technical Context

The device implements a dedicated USB Type-C subsystem with two Deep Sleep comparators for CC line attach/detach detection, programmable Rp terminations, and high-voltage-tolerant CC pins (VBUS short protection up to 20 V). Its VBUS control path integrates three independent reverse-current protection mechanisms - sensing across Rsense (CSP/CSN), across the NFET (VBUS/CSN), and via voltage-divider threshold (Vbus_max_det) - all triggering sub-1 µs FET shutdown.

The MCU subsystem runs at 16 MHz on a 32-bit Arm Cortex-M0 core with 32 KB SROM for boot routines, enabling firmware-upgradable UCSI stack execution. The 8-bit SAR ADC and TCPWM block support auxiliary system monitoring and timing-critical functions, while dual I²C interfaces handle both host UCSI communication and external redriver/mux control.

Key Specifications

Pinout & Package

Package: 40-QFN, 0.5 mm pitch, exposed thermal pad; supports industrial temperature range (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB Type-C port controller applications.

Compared with TUSB564RGER and UPD350A-EVAL, CYAC1126-40LQXIT provides highest integration for non-PD Type-C source applications - combining MCU, PHY, VBUS switch, VCONN drivers, and BC v1.2 in one 40-QFN package - reducing PCB area, BoM count, and firmware development effort.

Availability

CYAC1126-40LQXIT is available at Aetrix Electronics and suitable for notebook adapter modules, desktop docking stations, and embedded industrial USB hubs requiring stable component supply, industrial temperature operation, and long-term lifecycle support.

Supply support for CYAC1126-40LQXIT 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 is a German semiconductor manufacturer specializing in power management, automotive MCUs, and connectivity solutions, with global manufacturing and quality certification to ISO/TS 16949 and ISO 9001.

CYAC1126-40LQXIT belongs to Infineon's ACG1F product line - designed specifically for cost-optimized, non-PD USB Type-C source applications in computing peripherals, where integration of controller, switch, and VCONN eliminates discrete components and simplifies layout.

FAQ

Does CYAC1126-40LQXIT support USB Power Delivery (PD)?

No. CYAC1126-40LQXIT implements only the USB Type-C physical layer (v1.3), including CC line detection, Rp termination, and VBUS control - but lacks USB PD protocol stack, BMC transceiver, or PD policy engine. It is explicitly designated as a "Type-A to Type-C Generation-1 FET" solution without PD capability.

What is the maximum VCONN power delivery capability?

CYAC1126-40LQXIT delivers up to 1.0 W to EMCA cables via either CC1 or CC2 using its dual integrated VCONN FETs. Only one FET is enabled at a time, and the V5V supply must be within 4.85–5.5 V. This meets USB Type-C specification requirements for active cable power.

Can the VBUS load switch be used in sink (consumer) mode?

No. The integrated VBUS load switch is configured exclusively for provider (source) operation - it controls VBUS output from the host system to the Type-C connector. The device does not support VBUS sinking, nor does it include sink-side protection or discharge circuitry.

Is firmware update supported in-system?

Yes. CYAC1126-40LQXIT supports in-system firmware updates via both the SWD debug interface and the primary I²C bus. The 16 KB flash memory is organized in 64-byte rows and can be reprogrammed without removing the device from the board, enabling field updates to UCSI behavior or protection thresholds.