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Texas Instruments UCC5628FQPR/81540
- Part No.:
- UCC5628FQPR/81540
- Manufacturer:
- Texas Instruments
- Category:
- Signal Terminators
- Package:
- -
- Datasheet:
-
UCC5628FQPR/81540.pdf
- Description:
- ANALOG INTERFACE
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Product details
Overview
UCC5628FQPR/81540 from Texas Instruments is a multimode active SCSI terminator IC that auto-selects single-ended (SE) or low-voltage differential (LVD) termination based on bus detection via DIFFB and DIFFSENS pins. It operates from 2.7 V to 5.25 V, provides 105 Ω differential impedance and 110 Ω SE impedance, and supports Ultra320 (SPI-4) standards in a 48-pin LQFP package for 0°C to 70°C operation.
For engineers reviewing the UCC5628FQPR/81540 datasheet, UCC5628FQPR/81540 pinout, UCC5628FQPR/81540 application, or UCC5628FQPR/81540 equivalent, this device enables seamless migration between legacy SE and modern LVD SCSI buses while maintaining signal integrity through failsafe biasing, thermal-aware packaging, and precise regulator-controlled termination voltages.
Technical Context
The UCC5628FQPR/81540 integrates three independent voltage regulators (1.25 V, 1.3 V, and 2.7 V) to drive SE and LVD termination networks with trimmed impedances and current sourcing/sinking capabilities. Its bus detection logic uses a three-level DIFFB input (0.5 V threshold for SE, 0.7–1.9 V for LVD, >2.4 V for HVD) with RC-filtered sensing for SPI-2 (50 Hz) and SPI-3/SPI-4 (100–300 ms).
It implements dual-mode termination switching via internal analog comparators and MOSFET-based ground drivers, with dedicated HS/GND pins thermally coupled to the die paddle for junction temperature reduction. The device disables all termination when HVD is detected, entering high-impedance state to avoid bus conflict.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.7 V to 5.25 V - supports 3.3 V systems with ±10% tolerance and cable drop margin |
| Differential Impedance | 105 Ω typical - matches 100–120 Ω differential SCSI bus requirements for Ultra2/Ultra3/Ultra160/Ultra320 |
| Single-Ended Impedance | 110 Ω typical - meets SCSI-1/SCSI-2/SCSI-3 and Ultra (Fast-20) termination standards |
| LVD Mode Supply Current | 25 mA typical - defines power budget for full-differential termination across 14 signal pairs |
| SE Mode Supply Current | 10 mA max - enables low-power termination when only single-ended devices are present |
| Operating Temperature | 0°C to 70°C - validated for commercial-grade industrial backplane and storage subsystem environments |
| Package | LQFP-48 (PT drawing) - includes 12 HS/GND thermal pads directly connected to die mount paddle |
Pinout & Package
The UCC5628FQPR/81540 is housed in a thermally enhanced 48-pin LQFP (PT) package with exposed die paddle and 12 dedicated HS/GND pins for heat conduction to PCB ground planes. Pin 1 is located at top-left corner (Q2 quadrant), with 0.5 mm pitch and 7.2 mm × 7.2 mm body size per JEDEC MS-026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| TRMPWR (Pin 3) | Main supply input | Accepts 2.7–5.25 V; bypassed externally with 4.7 µF capacitor to GND for stable regulator operation |
| GND (Pin 25) | Analog reference ground | Reference node for all internal regulators and termination circuits; separate from HS/GND thermal paths |
| HS/GND (Pins 4–9, 28–33) | Thermal ground connection | Directly bonded to die paddle; must connect to large copper pour or multilayer ground plane for thermal management |
| DIFFB (Pin 34) | Filtered diff sense input | RC-filtered (50 kΩ + 4.7 µF) input detecting bus mode: <0.5 V = SE, 0.7–1.9 V = LVD, >2.4 V = HVD |
| DIFFSENS (Pin 35) | Diff sense output driver | Drives DIFFB line at 1.3 V in LVD mode; pulled to GND by SE devices; pulled high by HVD transceivers |
| DISCNCT (Pin 36) | Terminator enable control | Low-active input; disables all termination and sets SE/LVD outputs to high-impedance when asserted |
| SE (Pin 26) | Mode status output | TTL-compatible open-drain output indicating SE mode detection; invalid during DISCNCT assertion |
| LVD (Pin 27) | Mode status output | TTL-compatible open-drain output indicating LVD mode detection; invalid during DISCNCT assertion |
Key Features
| Feature | Design Value |
|---|---|
| Auto-switching SE/LVD termination | Eliminates manual jumper configuration and supports mixed-device SCSI buses without firmware intervention |
| Failsafe differential biasing | Maintains 125 mV common-mode bias and 100–110 Ω differential impedance to prevent signal reflection and ensure noise margin |
| Triple integrated regulators | 1.25 V (for LVD termination), 1.3 V (for DIFFSENS), and 2.7 V (for SE termination) - each trimmed and tested for precision |
| Thermal-enhanced LQFP package | 12 HS/GND pins reduce junction-to-board thermal resistance, enabling reliable operation at full load in compact enclosures |
| HVD-safe shutdown | Enters high-Z state upon detecting >2.4 V on DIFFB - prevents bus contention and damage when HVD devices are present |
Applications
| SCSI Backplane Termination | Ultra320 Storage Subsystem |
|---|---|
Use Scenario: Termination of 16-bit wide Ultra320 SCSI parallel bus in rack-mounted storage enclosures with hot-swap capability. IC Role / Device Role / Timing Role: Active multimode terminator providing dynamic SE/LVD selection and failsafe biasing for signal integrity at 320 MB/s transfer rates. Use Value: Enables backward compatibility with legacy SE drives while supporting next-generation LVD tape libraries and disk arrays on same backplane. | Use Scenario: End-of-bus termination in Fibre Channel-to-SCSI bridge modules where SCSI bus length and stub count vary across OEM configurations. IC Role / Device Role / Timing Role: Bus-type detector and regulator-driven terminator ensuring correct impedance matching regardless of attached device mix. Use Value: Removes need for manual DIP-switch configuration or multiple BOM variants, reducing design validation effort and field failure risk. |
| Industrial RAID Controller | Legacy Server Upgrade Kit |
Use Scenario: Integration into ruggedized RAID controllers deployed in factory automation systems requiring long-term component availability. IC Role / Device Role / Timing Role: Thermally robust terminator with HS/GND thermal path, operating continuously at 60°C ambient with no derating. Use Value: Extends MTBF by lowering junction temperature vs. standard LQFP packages, critical for fanless industrial deployments. | Use Scenario: Retrofit termination module for upgrading aging SCSI-2 servers to support Ultra160 LVD peripherals without motherboard redesign. IC Role / Device Role / Timing Role: Drop-in replacement for obsolete passive terminators, adding auto-detection and regulated voltage termination. Use Value: Delivers 110 Ω SE and 105 Ω LVD impedance with <0.3 pF pin-to-pin capacitance balance - meeting Ultra160 signal integrity specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCSI termination applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC5628FQP | No TR suffix; supplied in tube (250 pcs), not tape-and-reel; identical electrical and thermal specs | Suitable for prototyping and low-volume production; lacks reel packaging for automated assembly | Select UCC5628FQP for evaluation or small-batch builds where reel handling is unnecessary |
| UCC5628FQPTR | Same die and package; shipped in 1000-piece tape-and-reel format with Q2 pin-1 quadrant marking | Optimized for SMT production lines requiring automated pick-and-place feeders and traceable lot control | Select UCC5628FQPTR for volume manufacturing with standard surface-mount processes |
Compared with UCC5628FQPR/81540, both alternatives share identical functionality and performance but differ only in packaging format and quantity - UCC5628FQP suits bench use, UCC5628FQPTR supports high-throughput assembly, while UCC5628FQPR/81540 is a specific distributor-part-number variant with verified traceability and extended lifecycle support.
Availability
UCC5628FQPR/81540 is available at Aetrix Electronics and suitable for SCSI backplane termination, Ultra320 storage subsystems, and industrial RAID controller designs requiring stable component supply, long-term obsolescence management, and RoHS-compliant green packaging.
Supply support for UCC5628FQPR/81540 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
Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions across industrial, automotive, and communications markets since 1930.
The UCC5628FQPR/81540 belongs to TI's Unitrode SCSI termination product line, engineered specifically for seamless migration from legacy single-ended to high-speed low-voltage differential SCSI interfaces in enterprise storage and industrial computing platforms.
FAQ
What is the primary function of the UCC5628FQPR/81540 in a SCSI system?
The UCC5628FQPR/81540 serves as an auto-sensing multimode active terminator for SCSI parallel buses. It dynamically selects single-ended (SE) or low-voltage differential (LVD) termination based on bus detection via the DIFFB and DIFFSENS pins, ensuring compliance with SCSI-1 through Ultra320 (SPI-4) standards without manual configuration. Its integrated regulators and thermal design make UCC5628FQPR/81540 suitable for high-density storage subsystems requiring reliable signal integrity across mixed-device environments.
Does the UCC5628FQPR/81540 support high-voltage differential (HVD) SCSI devices?
No, the UCC5628FQPR/81540 does not support HVD SCSI devices. When the DIFFB input detects a voltage above 2.4 V - indicative of an HVD transceiver - the UCC5628FQPR/81540 automatically enters a high-impedance state, disabling all termination to prevent bus contention or damage. This behavior is explicitly defined in the datasheet and confirmed by its absolute maximum ratings and functional description.
How does the UCC5628FQPR/81540 manage thermal performance in continuous operation?
The UCC5628FQPR/81540 uses a thermally enhanced LQFP-48 package with 12 dedicated HS/GND pins directly connected to the die mount paddle. These pins conduct heat from the silicon die to the PCB ground plane, significantly lowering junction temperature and improving MTBF. Layout guidelines require connecting all HS/GND pins to a large copper area or multilayer ground plane - a design requirement validated in TI's thermal characterization data for UCC5628FQPR/81540.
What external components are required for proper operation of the UCC5628FQPR/81540?
The UCC5628FQPR/81540 requires three key external components: a 4.7 µF capacitor from TRMPWR to GND (Pin 3 → Pin 25), a 4.7 µF capacitor from REG to GND (Pin 10 → Pin 25), and a 4.7 µF capacitor plus 50 kΩ resistor from DIFFB to GND (Pin 34 → GND). These components stabilize the internal regulators and implement the SPI-3/SPI-4 compliant RC filter on the DIFFB input - all specified in the official SLUS302C datasheet for UCC5628FQPR/81540.
Can the UCC5628FQPR/81540 be used in 3.3 V-only systems with tight voltage margins?
Yes, the UCC5628FQPR/81540 is explicitly designed for 3.3 V systems with ±10% tolerance, operating down to 2.7 V TRMPWR. Its 2.7 V regulator ensures stable SE termination even under worst-case conditions including fuse/diode drops and cable voltage loss. TI confirms this capability in the Application Information section of SLUS302C, noting that all Unitrode LVD/multimode terminators - including UCC5628FQPR/81540 - are rated for 2.7 V minimum supply to accommodate real-world 3.3 V distribution limitations.
UCC5628FQPR/81540 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- -
- Number of Terminations:
- -
- Voltage - Supply:
- -
- Operating Temperature:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
UCC5628FQPR/81540 FAQ
1.How can I place an order for UCC5628FQPR/81540 through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC5628FQPR/81540 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for UCC5628FQPR/81540 reliable?
The price and inventory of UCC5628FQPR/81540 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC5628FQPR/81540 is usually 5 days.
3.What payment methods are accepted for UCC5628FQPR/81540?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC5628FQPR/81540 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC5628FQPR/81540?
UCC5628FQPR/81540 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC5628FQPR/81540 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for UCC5628FQPR/81540?
For technical support, including UCC5628FQPR/81540 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC5628FQPR/81540 requirements.
6.How does Aetrix verify that UCC5628FQPR/81540 is sourced from the original manufacturer or authorized distributors?
All UCC5628FQPR/81540 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that UCC5628FQPR/81540 meets industry standards.
7.What is the process for return or replacement of UCC5628FQPR/81540?
All UCC5628FQPR/81540 units undergo pre-shipment inspection (PSI). If there is an issue with UCC5628FQPR/81540, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The UCC5628FQPR/81540 part is unused and in its original packaging.
Return procedure for UCC5628FQPR/81540:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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