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Texas Instruments UCC5638FQPTR
- Part No.:
- UCC5638FQPTR
- Manufacturer:
- Texas Instruments
- Category:
- Signal Terminators
- Package:
- 48-LQFP
- Datasheet:
-
UCC5638FQPTR.pdf
- Description:
- IC SCSI 15-LINE TERM 48-LQFP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
UCC5638FQPTR from Texas Instruments is a multimode active SCSI terminator IC that auto-detects and switches between Single-Ended (SE) and Low-Voltage Differential (LVD) termination modes via the DIFFB and DIFFSENS pins, supports 15-line SCSI bus termination, operates from 2.7V to 5.25V TRMPWR, and is qualified for 0°C to +70°C ambient temperature in LQFP-48 package - deployed in Ultra320 (SPI-4) storage backplanes and server RAID controllers.
For engineers reviewing the UCC5638FQPTR datasheet, UCC5638FQPTR pinout, UCC5638FQPTR application, or UCC5638FQPTR equivalent, key selection criteria include its automatic SE/LVD mode detection logic, differential bias voltage (100–125 mV), 100–110 Ω differential impedance, 102.3–117.7 Ω single-ended impedance, and thermal-enhanced LQFP package with ground paddle for junction temperature control.
Technical Context
The UCC5638FQPTR implements a three-level bus sensing architecture: DIFFSENS detects HVD (>2.2 V), LVD (0.7–1.9 V), or SE (<0.5 V) conditions; DIFFB filters noise with 100–300 ms RC time constant; internal comparators tolerate ground shifts to ensure robust mode switching across mixed SCSI device environments.
It integrates three independent regulators (1.25 V, 1.3 V, 2.7 V) for LVD biasing, diff-sense reference, and SE termination voltage respectively; each regulator delivers specified source/sink current (e.g., –700 mA / +300 mA for 1.25 V regulator); termination is disabled entirely when DISCNCT is low, reducing idle current to 250–400 µA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Termination Modes | Auto-switched SE or LVD based on DIFFSENS voltage level; high-impedance shutdown for HVD detection |
| Differential Impedance | 100–110 Ω - matches SPI-2/3/4 100 Ω differential line requirements for signal integrity |
| Single-Ended Impedance | 102.3–117.7 Ω - calibrated to meet SCSI-2/Ultra2 SE termination standards |
| TRMPWR Range | 2.7 V to 5.25 V - supports 3.3 V systems with ±10% tolerance and cable drop margin |
| Supply Current (LVD) | 20–25 mA - enables low-power operation in active LVD mode without thermal derating |
| Operating Temperature | 0°C to +70°C - validated for commercial-grade server and storage enclosure environments |
| Differential Bias Voltage | 100–125 mV - ensures proper common-mode offset for Ultra160/320 receivers |
Pinout & Package
The UCC5638FQPTR is housed in a thermally enhanced 48-pin LQFP (PT) package with exposed die paddle connected to ground pins (pins 4–9, 28–33) for junction temperature reduction; package height ≤1.6 mm, MSL Level-3, RoHS-compliant NIPDAU finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| L1+ to L15+ | SCSI signal line positive / SE ground reference | 15 bidirectional lines: drive to GND in SE mode; form differential pair with corresponding Lx− in LVD mode |
| L1− to L15− | SCSI signal line negative / SE termination return | Paired with Lx+; maintains <0.1 pF capacitance imbalance per pair critical for Ultra320 timing margins |
| DIFFB | Differential sense filter input | Accepts RC-filtered DIFFSENS signal (4.7 µF capacitor required); enables noise-immune bus type detection |
| DIFFSENS | SCSI bus differential sense line interface | Monitors bus-driven diff-sense voltage: 0 V → SE, 1.3 V → LVD, >2.2 V → HVD shutdown |
| DISCNCT | Terminator enable/disable control | Low = active termination; high = high-Z shutdown (250–400 µA idle current) |
| TRMPWR | Main power supply input | 2.7–5.25 V input; bypassed with 4.7 µF capacitor near pin to stabilize regulator outputs |
| REG | Regulator bypass terminal | Connects to 4.7 µF capacitor for 1.25 V/1.3 V/2.7 V regulator stability and ripple suppression |
| HS/GND (pins 4–9, 28–33) | Thermal ground / heat sink connection | Directly tied to die paddle; must connect to large PCB copper pour or via-stitched ground plane for MTBF improvement |
Key Features
| Feature | Design Value |
|---|---|
| Auto SE/LVD mode selection | Eliminates manual jumper configuration and prevents mismatched termination in mixed-device SCSI buses |
| Failsafe differential biasing | Maintains 1.15–1.35 V common-mode voltage and 100–125 mV differential bias to prevent receiver saturation in SPI-4 links |
| Three integrated regulators | 1.25 V (LVD bias), 1.3 V (DIFFSENS reference), 2.7 V (SE termination) - reduce external component count by ≥4 discrete regulators |
| Thermally optimized LQFP | Exposed paddle + 12 dedicated HS/GND pins lower junction temperature by up to 15°C vs standard LQFP, improving long-term reliability |
| Ultra320-capable capacitance balance | ≤0.1 pF inter-pin and ≤0.3 pF inter-pair capacitance mismatch - meets strict 0.5 pF/line Ultra320 balance requirement |
Applications
| RAID Controller Backplane | Enterprise Tape Library Interface |
|---|---|
|
Use Scenario: Termination at both ends of a 16-bit Ultra320 SCSI bus connecting dual-host RAID controllers to disk enclosures. IC Role / Device Role / Timing Role: Active multimode terminator providing auto-detected LVD termination with 100 Ω differential impedance and failsafe biasing for 320 MB/s data transfer. Use Value: Prevents signal reflections and jitter accumulation across 1.5 m backplane traces, enabling stable operation at maximum SPI-4 clock rate (80 MHz). |
Use Scenario: Mid-plane termination in robotic tape library with mixed legacy SE and modern LVD tape drives. IC Role / Device Role / Timing Role: Bus-type agnostic terminator that switches to SE mode when legacy drives are detected and disables on HVD presence. Use Value: Enables seamless integration of new LVD drives into existing SE infrastructure without firmware or hardware reconfiguration. |
| Server Storage Expansion Card | SCSI-to-SAS Bridge Module |
|
Use Scenario: Add-in card providing two independent Ultra160 SCSI channels with end-of-bus termination. IC Role / Device Role / Timing Role: Dual-channel termination IC managing 15-line SE/LVD switching per channel using shared DIFFSENS routing. Use Value: Reduces BOM count by replacing two discrete terminators; thermal ground pins simplify heatsinking in space-constrained PCIe card layout. |
Use Scenario: Bridging legacy SCSI peripherals to SAS-based storage management systems via protocol translation. IC Role / Device Role / Timing Role: Physical layer terminator ensuring signal integrity on SCSI side while SAS transceivers handle link-layer conversion. Use Value: Maintains <0.3 pF inter-pair capacitance balance required for Ultra320 eye diagram compliance, avoiding bit errors during bridge handshaking. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCSI termination applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC5636FQPTR | 12-line termination (vs. 15-line); identical SE/LVD auto-detection, same LQFP-48 package and regulator set | Suitable only for narrow (8-bit) or 12-line SCSI buses; not compliant with Ultra320 16-bit wide bus requirements | Select UCC5636FQPTR only when bus width is ≤12 lines and full 15-line support is unnecessary |
| MAX3218EAPL+ | Single-ended-only termination; no LVD mode or DIFFSENS interface; 5 V tolerant; SO-28 package | Limited to legacy SE-only systems; cannot coexist with LVD devices; lacks failsafe biasing and thermal ground design | Choose MAX3218EAPL+ only for cost-sensitive, non-upgradable SE-only embedded systems where LVD compatibility is irrelevant |
Compared with UCC5638FQPTR, UCC5636FQPTR reduces line count but sacrifices Ultra320 compliance, while MAX3218EAPL+ eliminates multimode flexibility and thermal performance - making UCC5638FQPTR the sole option for future-proof, high-reliability 15-line LVD/SE-mixed SCSI termination.
Availability
UCC5638FQPTR is available at Aetrix Electronics and suitable for RAID controller backplanes, enterprise tape libraries, server storage expansion cards, and SCSI-to-SAS bridge modules requiring stable component supply across extended production lifecycles.
Supply support for UCC5638FQPTR 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, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.
The UCC5638FQPTR belongs to TI's SCSI interface and termination product line, engineered specifically for high-speed parallel storage interconnects requiring automatic multimode compatibility, thermal resilience, and Ultra320 signal integrity compliance.
FAQ
What is the primary function of the UCC5638FQPTR in a SCSI system?
The UCC5638FQPTR serves as an intelligent multimode active terminator that automatically detects whether connected SCSI devices operate in Single-Ended (SE) or Low-Voltage Differential (LVD) mode-and configures its 15-line termination accordingly. It uses the DIFFSENS and DIFFB pins to monitor bus voltage levels and switch modes without external intervention. This ensures optimal signal integrity across SPI-2, SPI-3, and SPI-4 standards. The UCC5638FQPTR also shuts down into high-impedance state if High-Voltage Differential (HVD) devices are detected, preventing bus conflicts.
Does the UCC5638FQPTR support Ultra320 (SPI-4) SCSI interfaces?
Yes, the UCC5638FQPTR explicitly supports Ultra320 (SPI-4) interfaces per its datasheet compliance statement and electrical specifications-including 100–110 Ω differential impedance, <0.3 pF inter-pair capacitance mismatch, and 100–125 mV differential bias voltage-all aligned with SPI-4 timing and signal integrity requirements. Its 15-line architecture matches the 16-bit Ultra320 bus (15 data + parity), and thermal design sustains operation under sustained 320 MB/s transfers. The UCC5638FQPTR is validated for use in Ultra320 RAID backplanes and tape library mid-planes.
How does the UCC5638FQPTR handle mixed SE and LVD devices on the same SCSI bus?
The UCC5638FQPTR handles mixed SE and LVD devices through its three-level DIFFSENS detection scheme: if DIFFSENS reads <0.5 V, it activates SE termination; if 0.7–1.9 V, it engages LVD termination; if >2.2 V, it enters high-impedance shutdown. Since SE devices short DIFFSENS to ground and LVD devices drive it to ~1.3 V, the UCC5638FQPTR reliably selects the dominant bus type. This behavior is confirmed in application note SLUS271B, and the UCC5638FQPTR will not attempt LVD termination if any SE device is present-ensuring safe interoperability without manual configuration.
What is the role of the HS/GND pins on the UCC5638FQPTR?
The HS/GND pins (pins 4–9 and 28–33) on the UCC5638FQPTR are thermally enhanced ground connections directly bonded to the internal die paddle. They conduct heat from the silicon die to the PCB ground plane, lowering junction temperature by up to 15°C compared to standard LQFP packages. Per TI's layout guidelines, these pins must be connected to a large copper pour or via-stitched ground plane-not just trace routing-to realize the specified MTBF and thermal performance. This thermal design is integral to the UCC5638FQPTR's reliability in continuous Ultra320 operation.
Can the UCC5638FQPTR be used on a High-Voltage Differential (HVD) SCSI bus?
No, the UCC5638FQPTR must not be used on an HVD SCSI bus. Its datasheet explicitly states: "The UCC5638 can not be used on a HVD, EIA485, differential SCSI bus." When the UCC5638FQPTR detects an HVD device via DIFFSENS voltage >2.2 V, it switches all terminations to high-impedance state-but this is a protective shutdown, not functional operation. Using the UCC5638FQPTR on an HVD bus risks signal integrity failure, undefined logic states, and potential damage due to voltage level incompatibility (HVD uses ±5 V signaling vs. UCC5638FQPTR's 0–5 V tolerance). Always verify bus type before deploying the UCC5638FQPTR.
UCC5638FQPTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 48-LQFP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- SCSI, LVD, SE
- Number of Terminations:
- 15
- Voltage - Supply:
- 2.7V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-LQFP (7x7)
UCC5638FQPTR FAQ
1.How can I place an order for UCC5638FQPTR through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC5638FQPTR 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 UCC5638FQPTR reliable?
The price and inventory of UCC5638FQPTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC5638FQPTR is usually 5 days.
3.What payment methods are accepted for UCC5638FQPTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC5638FQPTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC5638FQPTR?
UCC5638FQPTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC5638FQPTR 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 UCC5638FQPTR?
For technical support, including UCC5638FQPTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC5638FQPTR requirements.
6.How does Aetrix verify that UCC5638FQPTR is sourced from the original manufacturer or authorized distributors?
All UCC5638FQPTR 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 UCC5638FQPTR meets industry standards.
7.What is the process for return or replacement of UCC5638FQPTR?
All UCC5638FQPTR units undergo pre-shipment inspection (PSI). If there is an issue with UCC5638FQPTR, 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 UCC5638FQPTR part is unused and in its original packaging.
Return procedure for UCC5638FQPTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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