CY7C68321-56LFXC - USB 2.0 to ATA Bridge | Infineon
MPN: CY7C68321-56LFXC ✓ ActiveCY7C68321-56LFXC Overview
A USB-to-ATA bridge is an interface controller within the broader USB interface IC category. It translates USB traffic and ATA storage commands so that a legacy ATA device can appear as a USB peripheral without requiring a host-side protocol converter to understand the ATA command set. This function places the CY7C68321-56LFXC in the storage-controller hierarchy: USB interface controller, mass-storage bridge, ATA/ATAPI interface controller, and ultimately a CMOS semiconductor.
The verified distributor information identifies the device as a USB Bridge with a USB 2.0 ATA interface in a 56-QFN (8x8) package. Its EZ-USB AT2LP family designation is also visible in distributor listings for the same MPN. The compact 56-QFN package supports space-constrained external storage, portable media, docking, and embedded USB storage designs where a larger through-hole or leaded bridge package would be undesirable.
The CY7C68321-56LFXC belongs to a family of related controllers including CY7C68321C-56LFXC, CY7C68300C-56LFXC, and CY7C68300B-56LFXC. The C suffix identifies different family revisions or ordering variants, but the supplied web data does not expose a verified electrical comparison table, operating-voltage range, or USB speed difference for each suffix. Engineers should therefore confirm the complete datasheet and firmware requirements before treating a related suffix as a drop-in substitution.
A key design consideration is that the device is a protocol bridge rather than a general-purpose USB host controller. The surrounding board must provide compliant USB 2.0 signal routing, ATA power management, storage-side connectivity, and the decoupling appropriate for its supply rails. USB differential-pair routing, ATA signal integrity, and the exposed-pad grounding arrangement of the QFN package require close attention in multilayer PCB layouts.
Typical implementation roles include an ATA flash-memory reader, a USB storage adapter, a portable storage enclosure, and a compact embedded USB-to-disk interface. Because the verified data does not provide the operating voltage, transfer rate, temperature range, or absolute maximum ratings, those values must be taken directly from the applicable manufacturer datasheet before schematic sign-off.
This page consolidates verified distributor listings, related family members, package information, and application-specific engineering guidance. It adds selection context and design notes beyond the basic catalog description while clearly separating verified facts from parameters that still require manufacturer documentation.
Drop-in alternatives for CY7C68321-56LFXC — 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 CY7C68321-56LFXC (same form factor and footprint) — differing in Package Dimensions, Storage Interface, Device Type, Package, Package Type.
CY7C68321C-56LFXC
✅ Drop-InContact for price
View Datasheet →CY7C68300C-56LFXC
✅ Drop-InContact for price
View Datasheet →CY7C68300B-56LFXC
✅ Drop-InContact for price
View Datasheet →CY7C68321-56LFXC Specifications
| Device Type | USB bus controller and USB-to-ATA bridge |
| Manufacturer | Infineon Technologies |
| Original Designer | Cypress Semiconductor Corp |
| USB Interface | USB 2.0 |
| Storage Interface | ATA |
| Interface Function | USB 2.0 to ATA bridge |
| Process Technology | CMOS |
| Package Type | 56-QFN (8x8) |
| Package Dimensions | 8 mm x 8 mm |
| Mounting Type | Surface Mount |
| Number of I/O Pins | 56 pins |
CY7C68321-56LFXC 8 mm x 8 mm Pin Configuration Guide
Pin configuration for CY7C68321-56LFXC (8 mm x 8 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 CY7C68321-56LFXC.
Refer to the datasheet for full pin configuration.
Typical Applications
CY7C68321-56LFXC is suitable for 6 applications: USB Flash-Memory Card Reader, External ATA Storage Adapter, Portable Storage Enclosure, Embedded USB-to-Disk Interface, ATA Storage Migration and Legacy Bridge, USB Storage Dongle.
USB Flash-Memory Card Reader
The CY7C68321-56LFXC fits a USB storage reader because it provides a dedicated USB 2.0-to-ATA interface bridge in a compact 56-QFN (8x8) package. Its ATA-side circuitry can connect the controller to compatible flash-memory or card-reader circuitry while the USB side handles enumeration and mass-storage communication with a host computer. The small surface-mount package reduces the space required beside a USB connector and allows the bridge, flash controller, and memory devices to be placed together on one PCB. Because the verified information does not state the supported ATA mode or maximum transfer rate, the design should use the exact manufacturer timing and interface tables before selecting flash devices, signal-conditioning components, or cable compensation.
Recommended
External ATA Storage Adapter
An external ATA storage adapter can use the CY7C68321-56LFXC to present an ATA-compatible disk device to a USB 2.0 host. The controller provides the protocol-bridging function between the USB and ATA interfaces, while the PCB supplies the connector, power-management circuitry, storage-side routing, and regulatory protections. Its 56-QFN (8x8) package is particularly useful when the adapter must remain compact and thermally constrained. Engineers should preserve USB differential impedance, provide ATA signal conditioning appropriate to the implemented topology, and confirm whether ATA master or slave behavior is required. The verified material identifies the interface but does not publish the complete role, timing, or power-limit data needed for final sign-off.
Recommended
Portable Storage Enclosure
The CY7C68321-56LFXC is suited to portable storage enclosures that connect ATA-based media to a USB host. Its USB 2.0-to-ATA bridge role supports the core data path, and the 56-QFN (8x8) package leaves board area for power regulation, protection devices, and connectors. Because the device is a surface-mount CMOS controller, assembly reliability depends on using the exact exposed-pad land pattern and adequate thermal-via distribution. Designers should also account for hot-plug behavior, cable discharge protection, and the difference between bus-powered and externally powered products. The verified data does not include operating-current or absolute-maximum limits, so thermal and power budgeting must use the matching manufacturer datasheet before the enclosure is released for production.
Recommended
Embedded USB-to-Disk Interface
Embedded systems can use the CY7C68321-56LFXC as the interface between a USB host and an ATA-based storage subsystem, avoiding a software ATA driver inside the embedded controller. The bridge translates between the USB 2.0 and ATA interfaces at the hardware level and fits within a small PCB footprint because it is offered in a 56-QFN (8x8) package. This arrangement is useful in industrial service equipment, data-acquisition systems, and legacy disk migration products. Validation should include enumeration behavior, transfer-error handling, power-state transitions, and the intended USB host environment. Since the supplied evidence does not specify the supported USB transfer rate, ATA timing modes, or operating limits, those details must remain design assumptions until confirmed against the exact datasheet.
Recommended
ATA Storage Migration and Legacy Bridge
The CY7C68321-56LFXC can serve as a migration path when an ATA device must be accessed from a modern USB host. Its verified ATA interface and USB 2.0 bridge function provide the electrical and protocol foundation for a dedicated adapter rather than requiring a legacy PC expansion card. The 56-QFN package also allows the adapter to fit into compact enclosures. Practical implementation still requires checking that the source device and target host expect compatible ATA modes, cable lengths, power levels, and command behavior. The related CY7C68321C, CY7C68300C, and CY7C68300B members should be evaluated against the target firmware requirements. The verified data does not disclose the full feature matrix, so each substitute must be approved through board-level and interoperability testing.
Recommended
USB Storage Dongle
The CY7C68321-56LFXC is applicable to a USB storage dongle that exposes ATA-compatible storage through a compact connector. Its USB 2.0 interface handles the host-facing side, while the ATA interface connects to compatible memory or storage circuitry. The 56-QFN (8x8) package supports dense dongle layouts without requiring a leaded bridge. Design work should focus on connector clearance, USB ESD and surge protection, stable bypass capacitance, and exposed-pad soldering. The controller should also be evaluated against the intended enumeration class and operating-system compatibility requirements. Because the verified distributor data contains no operating-voltage, current-consumption, or transfer-rate values, those specifications must be obtained before power-budget calculations or marketing claims are published.
Recommended
Recommended Products Summary
Engineering reference data for CY7C68321-56LFXC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CY7C68321C-56LFXC | CY7C68300C-56LFXC | CY7C68300B-56LFXC |
|---|---|---|---|---|
| Package | 56-VQFN (8x8) | 56-VQFN (8x8) | 56-VQFN (8x8) | 56-VQFN (8x8) |
| Brand | Infineon Technologies | Cypress Semiconductor | Cypress Semiconductor | Cypress Semiconductor |
| Device Function | USB 2.0 to ATA bridge | USB 2.0 ATA interface controller | USB 2.0 AT2LP bridge | USB 2.0 AT2LP bridge |
| Storage Interface | ATA | ATA | ATA/AT2LP family | ATA/AT2LP family |
| USB Interface | USB 2.0 | USB 2.0 | USB 2.0 | USB 2.0 |
| Pin Count | 56 pins | 56 pins | 56 pins | 56 pins |
Key Differentiators
- Exact non-suffixed order code is identified by the distributor listing (vs CY7C68321C-56LFXC)
- Verified USB 2.0-to-ATA bridge function in a compact surface-mount package (vs CY7C68015A-56LFXC)
- Documented ATA interface rather than a generic USB peripheral (vs CY7C68300B-56LFXC)
Design Notes
Route the USB 2.0 differential pair as a tightly coupled pair with a continuous reference plane, avoid plane splits and unnecessary stubs, and use the board stack-up impedance targets for the host connection. Keep USB protection components close to the connector and their return path short. For the ATA side, follow the manufacturer's topology and termination guidance for the supported transfer rate; the verified web results do not supply the ATA timing specification, so series damping and filtering values must not be copied from an unrelated controller.
Use the exact 56-QFN (8x8) land pattern from the manufacturer package drawing and verify the exposed-pad connection and thermal-via recommendation. The canonical package-diagram library has no 56-QFN entry, so the default diagram is used and a detailed pinout cannot be presented. Place bypass capacitors at the supply pins with very short ground returns, and provide adequate copper for heat spreading where the calculated dissipation is significant.
Do not assume that the related C or B suffix is electrically identical to the non-suffixed order code. CY7C68321C-56LFXC, CY7C68300C-56LFXC, and CY7C68300B-56LFXC are the only same-family drop-in candidates identified by the supplied search evidence, but their complete revision details are not published in that evidence. Before substitution, compare exact pin names, supply limits, timing, firmware support, ATA features, and package drawings. Never infer pin compatibility solely from the shared 56-VQFN package name.
Estimate the bridge power budget using the exact operating voltage and supply current from the manufacturer datasheet; those values are unavailable in the verified search data and must not be guessed. For a USB-powered design, include the host-current budget, ATA-load requirements, regulator dropout, transient margin, and protection-device losses. The calculation should separately cover suspend, active-idle, enumeration, and sustained-transfer states before the cable and power-supply components are selected.
Compliance Information
The supplied distributor and cross-reference results do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is recorded as unknown because this is a storage-interface IC and no automotive qualification statement appears in the verified data.
