1. Draw the Data Relationship Before Counting Ports
A hub requirement begins with a relationship, rather than a row of connectors. Identify the connection leading toward the host and the connections intended for attached devices. Label those roles on the application's block diagram. The purpose is to establish what the requested component must connect, so that upstream and downstream retain a consistent meaning throughout the component enquiry.
Keep the hub's role distinct from the appearance of the finished product. A docking enclosure, internal board or panel can expose connections that do not correspond directly to the component's data-port description. Purchasing needs the hub requirement associated with the actual board design. A photograph or connector count can describe the assembly, but cannot resolve an unidentified connection's place in that topology.
Use the role diagram to make candidate comparisons specific. Ask which documented connection on the proposed hub serves each required relationship. Leave an incomplete mapping as a topology question, rather than substituting an apparently similar port count. This first comparison concerns the data architecture. It does not establish a physical pin assignment, a completed board connection or a result with the intended host.
2. Read the Hub's Own Upstream and Downstream Description
TI's TUSB8041 product description distinguishes its upstream connection from its downstream connections. Use that named example to see why the two roles belong in separate requirement fields. The manufacturer describes the connections in the context of that hub family. Preserve the exact component reference when applying the wording, rather than treating every product advertised as a USB hub as an identical architecture.
An upstream description answers where the hub connects toward the host; a downstream description answers how it presents connections toward attached devices. These are data-path roles. They should not be relabelled with the source and sink terms used in a separate USB Power Delivery configuration. A product may involve both subjects, but each component decision needs its own applicable evidence.
Keep the architectural description separate from qualification of a complete connection. The overview helps identify the intended hub function. It does not demonstrate that a proposed board, host, operating system and attached device have been assessed together. Carry those application questions forward under their own references instead of allowing an upstream or downstream label to stand in for a successful system result.
3. Specify Downstream Power Control Separately
The TUSB8041 information also distinguishes individually controlled and ganged downstream power arrangements. At the requirement level, these describe different ways of controlling the downstream group. Individual control and control applied to a group should therefore occupy a separate decision from the identification of upstream and downstream data roles. A headline number of ports leaves that power-control requirement incomplete.
Ask whether the application requires downstream connections to be governed independently or together, and identify the released design reference supporting that choice. Keep the intended power arrangement linked to the appropriate hub requirement. The distinction is useful before component selection, while the actual switching circuitry and detailed operating conditions remain matters for the exact-device and board review. This guide supplies no wiring or configuration procedure.
A charging feature introduces another question rather than resolving the first two. The presence of charging terminology does not identify the host-facing data connection or decide whether downstream power is individually controlled. Keep the requested hub role, downstream power arrangement and any separate charging requirement distinguishable. Do not derive USB-C power roles or a charging setup from this qualitative hub example.
4. Compare Candidates Against the Same Role Definition
Use a role-and-power comparison rather than a single port-count column. For each candidate, ask where the host-facing connection belongs, which connections serve attached devices and which power arrangement governs those downstream connections. Those answers reveal whether two products are addressing the same architecture. A matching headline count should not conceal a different connection role or an unanswered power-control requirement.
Consider an application requirement that needs a particular downstream connection's power to be governed separately from the remaining group. That requirement raises an individual-control question even if the data-port roles already match. If the design instead calls for collective control, preserve that requirement explicitly. This comparison explains why power arrangement can change the selection question without changing the words upstream and downstream.
Close the technical comparison with the manufacturer's role descriptions and the application's intended power arrangement beside each other. Ask engineering to resolve any mismatch before a proposed hub replaces the released item. Detailed board implementation, programming and host qualification remain separate reviews. The initial enquiry is complete when it identifies those decisions clearly, rather than claiming that a broad hub description has settled them.
Sources and further reading
TI's TUSB8041 product description supports the qualitative upstream/downstream and individual/ganged downstream power distinctions. No electrical limits, programming procedure, host qualification or current supply claim is provided.