USB3503-I/ML

Controllers Overview

The USB3503-I/ML is a low-power, USB 2.0 hub controller featuring an HSIC upstream port and three downstream ports. It operates within a supply voltage range of 2.8 V to 3.6 V, with a typical operating current of 24 mA. The device supports High Speed (HS) data rates up to 480 Mb/s and includes integrated 3.3V and 1.2V regulators for single-supply operation. Designed for mobile applications, it offers advanced power-saving features, including a standby mode with 1 µA typical current consumption. The component is housed in a 32-pin SQFN package and functions as a configurable hub controller.

Controllers Feature Summary

• Integrated USB 2.0 compatible 3-port hub with dedicated Transaction Translators per port for consistent full-speed throughput.
• Advanced power management capabilities including standby mode with 1 µA typical current and automatic port shutdown when disabled.
• Configurable via serial I2C slave interface for custom VID/PID/DID, string descriptors, and port mapping sequences.
• Built-in signal integrity enhancements such as PHYBoost for programmable drive strength and VariSense for receiver sensitivity.

Controllers Applications

• Mobile Phones
• Tablet Computers
• Ultra Mobile PCs
• Digital Still Cameras
• Gaming Consoles

Controllers Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to confirm package type and temperature grade. Ensure that any external components, such as reference clocks or bypass capacitors, meet the electrical specifications outlined in the official documentation. Confirm RoHS compliance status directly from the product release notes before finalizing procurement orders.

Controllers Selection Notes

Select this component for designs requiring a compact USB hub solution with minimal external passive components. The integrated regulators simplify power architecture, while the I2C configurability allows adaptation to various host systems. Ensure the system clock frequency matches one of the supported REFCLK options defined in the datasheet to guarantee proper PLL synchronization and high-speed operation.

Controllers Part Context

The USB3503 series is optimized for portable embedded systems where power efficiency and small form factors are critical. The -I/ML variant specifically denotes the industrial temperature range (-40°C to +85°C) and the 32-pin SQFN package. This part serves as a bridge between HSIC host controllers and standard USB peripherals, reducing bill-of-materials complexity through integrated termination resistors and biasing.

Controllers Replacement Considerations

Consult Microchip Technology for officially confirmed substitute part numbers. Verify pin compatibility and electrical specifications if considering alternative manufacturers. Do not assume functional equivalence without reviewing the complete datasheet of the proposed replacement component.

Controllers FAQ

How is the reference clock frequency selected?

The reference clock frequency is selected by setting the REF_SEL pins according to the values specified in Table 3-3 or Table 3-4 of the datasheet, depending on whether the INT_N pin is sampled high or low during the Hub.Init stage.

What is the function of the HUB_CONNECT pin?

The HUB_CONNECT pin controls the transition to the Hub Communication Stage. It can be tied to ground, VDD33_BYP, or driven by a signal to initiate communication based on the configuration register settings.

Does the USB3503 support compound devices?

Yes, the USB3503 supports compound devices on a port-by-port basis, allowing for flexible integration of multi-function peripherals.