USB2503A-HZH - USB 2.0 3-Port Hub Controller | Microchip
MPN: USB2503A-HZH ✓ ActiveUSB2503A-HZH Overview
A USB hub controller is an interface IC within the USB interface-controller hierarchy. It connects one upstream USB host connection to multiple downstream USB ports, allowing peripherals such as storage devices, keyboards, network adapters, and industrial USB modules to share one host port. Unlike a host controller that manages operating systems and device software, the USB2503A-HZH handles USB signaling, port transactions, configuration, and power distribution while requiring no firmware development.
The principal features include full USB 2.0 operation, one transaction translator per downstream port, low-speed, full-speed, and high-speed device support, per-port or ganged power control, and detection of both bus-powered and self-powered operating conditions. Configuration can use pin-selectable defaults, an external serial EEPROM, or a microcontroller interface. When the microcontroller interface is used, the hub operates as an SMBus slave device.
In the architecture described by the Microchip USB2503/USB2503A datasheet 00002249A, dynamic power switching monitors the external SELF_PWR input. If the available power source changes, the hub disconnects downstream devices and the upstream connection before reattaching in the appropriate bus-powered or self-powered configuration. External 10 kΩ pull-up resistors are recommended on SDA/SMBDATA and SCL/SMBCLK/CFG_SEL0 lines according to the SMBus 1.0 Specification and EEPROM-manufacturer guidance.
Typical implementations include compact desktop USB expansion, USB-to-serial systems, embedded equipment with multiple service connections, data-acquisition equipment, and powered peripherals. The three downstream ports are useful when a compact host interface must support several external devices without adding another system controller.
The primary design constraint is accurate implementation of USB power, signal routing, configuration straps, and exposed-pad thermal management. Maintain the specified USB differential routing and supply decoupling, and verify the external power-source transition behavior before enabling downstream loads. Because the available web data does not provide a complete pin table, designers should use the manufacturer datasheet for final pin assignments and layout values.
This page consolidates the verified USB 2.0 speeds, operating range, package information, configuration methods, and sourcing links for USB2503A-HZH. It also identifies the manufacturer's recommended USB2513B replacement direction while clearly distinguishing a documented replacement path from a verified pin-for-pin drop-in substitute.
Drop-in alternatives for USB2503A-HZH — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with USB2503A-HZH (same form factor and footprint) — differing in Configuration Interface, Operating Temperature, Package, Transaction Translators.
USB2503-HZH
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →USB2503A
✅ Drop-In📋 Reference alternative (not in catalog)
USB2513B-HZH
✅ Drop-In📋 Reference alternative (not in catalog)
USB2503A-HZH Specifications
| Product Type | USB 2.0 three-port hub controller |
| USB Standard | USB 2.0 |
| Downstream Port Count | 3 ports |
| Transaction Translators | 3, one per downstream port |
| High-Speed Operation | 480 Mb/s |
| Full-Speed Operation | 12 Mb/s |
| Low-Speed Operation | 1.5 Mb/s |
| Operating Supply Voltage | 1.62 V to 3.6 V |
| Supply Current | 100 mA |
| Configuration Interface | Serial EEPROM, microcontroller, or pin-selectable options |
| Microcontroller Interface | SMBus slave device |
| Downstream Power Control | Per-port or ganged, selectable |
| Power Source Detection | Bus-powered and self-powered source detection |
| Operating Temperature | 0 °C to 70 °C |
| Package | 48-QFN-EP, 7 x 7 mm |
| Firmware Requirement | No firmware development required |
| External Pull-Up Resistors | 10 kΩ recommended on SDA/SMBDATA and SCL/SMBCLK/CFG_SEL0 |
| RoHS Status | Compliant |
| Lifecycle Status | Active |
USB2503A-HZH 48-qfn-ep, 7 x 7 mm Pin Configuration Guide
Pin configuration for USB2503A-HZH (48-qfn-ep, 7 x 7 mm package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for USB2503A-HZH.
Refer to the datasheet for full pin configuration.
Typical Applications
USB2503A-HZH is suitable for 6 applications: Compact Desktop USB Expansion, USB-to-Serial Adapter, Industrial Data-Acquisition Equipment, Embedded Equipment with Multiple USB Service Ports, Powered USB Peripherals, USB Storage and Media Hub.
Compact Desktop USB Expansion
USB2503A-HZH fits a compact desktop hub because it adds three downstream USB ports to one upstream host connection while supporting all USB 2.0 speeds. The controller can operate at 480 Mb/s for storage, 12 Mb/s for peripherals, and 1.5 Mb/s for low-speed devices, with one transaction translator per port. Configuration can be established by pin straps or an external EEPROM, avoiding firmware development for basic hub operation. A powered implementation can use the self-powered detection function and selectable per-port or ganged power control. The principal design trade-off is that the 48-QFN-EP package requires careful USB routing and exposed-pad thermal management, particularly when several downstream devices draw current simultaneously.
Recommended
USB-to-Serial Adapter
USB2503A-HZH can form the hub section of a multi-port USB-to-serial adapter because its three downstream ports operate at the USB 2.0 low-, full-, and high-speed rates. A serial interface can attach downstream while additional low-speed or full-speed peripherals share the same host port. The hub's 1.62 V to 3.6 V operating range supports integration into a regulated controller board, while EEPROM or SMBus-slave configuration permits product-specific settings. Because the verified data does not provide total-current limits, the adapter designer must calculate worst-case downstream demand and validate the self-powered path against the manufacturer datasheet before finalizing the power architecture.
Recommended
Industrial Data-Acquisition Equipment
USB2503A-HZH is useful in data-acquisition equipment where multiple sensors, service tools, or storage devices need one host interface. Its three transaction translators isolate the downstream traffic paths, while support for low-speed 1.5 Mb/s and full-speed 12 Mb/s devices allows the system to combine different USB device classes. The hub requires no dedicated firmware, reducing processor overhead, and the 0 °C to 70 °C specification covers commercial operating environments. For installations with wider temperature requirements or substantially higher downstream current, the part should not be assumed qualified; the complete power limits, protection requirements, and system thermal conditions must be verified in datasheet 00002249A.
Recommended
Embedded Equipment with Multiple USB Service Ports
USB2503A-HZH supports embedded equipment that needs multiple USB service connections without adding another host controller. The upstream interface connects to the equipment processor, while three downstream ports can serve configuration, logging, or maintenance peripherals. Pin-selectable configuration supports a simple fixed installation, whereas EEPROM or microcontroller configuration supports a configurable platform; in the latter mode, the hub appears as an SMBus slave. Its support for bus-powered and self-powered source detection is particularly useful in serviceable equipment where power-source state changes must be handled cleanly. Exact port-current budgeting remains necessary because the verified excerpts do not state maximum downstream current.
Recommended
Powered USB Peripherals
USB2503A-HZH is appropriate for powered peripherals that expose several downstream connections, such as docking stations, media interfaces, and test equipment. The controller supports both bus-powered and self-powered operation and can dynamically detect changes in the available power source. When dynamic power switching is enabled, it monitors SELF_PWR and removes downstream power before changing the operating configuration, preventing devices from receiving an invalid supply state. Per-port or ganged power control lets the system balance circuit simplicity against independent port management. Designers must still determine downstream switch ratings, inrush behavior, and thermal performance because those numerical requirements are not present in the verified web excerpts.
Recommended
USB Storage and Media Hub
USB2503A-HZH can support a storage and media hub that combines high-speed devices with slower peripherals. A high-speed storage target can operate at 480 Mb/s while another downstream port serves a full-speed 12 Mb/s or low-speed 1.5 Mb/s accessory. The independent transaction translators allow each port to execute its own USB transaction schedule, which is useful in mixed-device systems. The controller also permits software or EEPROM configuration when port behavior must be customized. Since a populated storage hub can impose substantial dynamic and steady-state current demands, the implementation should follow the manufacturer power-distribution guidance and validate the external SELF_PWR logic rather than infer limits from the generic 100 mA supply-current listing.
Recommended
Recommended Products Summary
Engineering reference data for USB2503A-HZH — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | USB2503-HZH | USB2503A | USB2513B-HZH |
|---|---|---|---|---|
| Package | 48-QFN-EP (7 x 7 mm) | 48-QFN-EP (7 x 7 mm) | 48-QFN-EP (7 x 7 mm) | 48-QFN-EP (7 x 7 mm) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Product Function | Three-port USB hub controller | Three-port USB hub controller | Three-port USB hub controller | Three-port USB hub controller replacement family |
| Downstream Port Count | 3 ports | 3 ports | 3 ports | 3 ports |
| Replacement Status | USB2513B is the manufacturer-suggested replacement family | Same USB2503 family | Base family order code | Suggested replacement family |
Key Differentiators
- Three independently translated downstream paths (vs USB2503-HZH)
- Hardware-first operation without firmware development (vs USB2513B-HZH)
- Mixed-speed USB 2.0 compatibility (vs USB2503A)
Design Notes
Implement the self-powered and bus-powered paths so that the external SELF_PWR signal accurately reflects the available source. According to the Microchip USB2503/USB2503A datasheet 00002249A, dynamic power switching monitors SELF_PRN and, when the source changes, disconnects downstream devices and the upstream port before reattachment. Do not substitute a similar signal name without checking the exact pin and polarity in the manufacturer document.
Place the USB differential traces as a controlled-impedance pair and minimize branch lengths, stubs, and unnecessary vias. Keep the hub controller, configuration pull-ups, and required decoupling close to their associated pins. The exposed pad under the 48-QFN-EP package must be connected according to the manufacturer layout guidance, with adequate thermal-copper area for the power dissipated by the controller and local regulators.
Do not assume that the listed 100 mA supply current is the maximum allowable downstream current or the total USB power budget. The supplied excerpts do not state maximum port current, total-current limits, or inrush requirements. Derive the external power-switch rating and loss budget from the complete datasheet limits and the attached USB devices, and verify behavior when the system changes between bus-powered and self-powered operation.
Use the manufacturer-recommended 10 kΩ external pull-ups on SDA/SMBDATA and SCL/SMBCLK/CFG_SEL0 unless the selected EEPROM or microcontroller interface specifies otherwise. Configuration pins can also serve limited strapping functions, so resistor placement and logic levels must be checked against the reset and configuration sequence in datasheet 00002249A. A mechanically correct board can still enumerate incorrectly if strap levels are inconsistent.
Compliance Information
RoHS compliance is stated in the verified USB2503 datasheet excerpt. The supplied data does not establish REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification status. The USB2503A product is an interface controller rather than an AEC-Q100-qualified automotive device unless a separate qualified orderable variant is documented.
