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Texas Instruments UC5612PWP
- Part No.:
- UC5612PWP
- Manufacturer:
- Texas Instruments
- Category:
- Signal Terminators
- Package:
- -
- Datasheet:
-
UC5612PWP.pdf
- Description:
- SCSI TERMINATOR, 9-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:1,800
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Product details
Overview
UC5612PWP from Texas Instruments is a 9-channel SCSI active termination IC with integrated 2.8-V regulator, 110-Ω trimmed impedance (±5%), −21.5-mA sinking current per channel, and 5-pF output capacitance - deployed at bus endpoints in narrow/wide SCSI-2 systems for noise margin optimization and hot-plug compliance.
For engineers reviewing the UC5612PWP datasheet, UC5612PWP pinout, UC5612PWP application, or UC5612PWP equivalent, key selection criteria include termination current tolerance, disconnect-mode supply current (100 µA), dropout voltage (1.2 V), thermal shutdown threshold (170 °C), and TSSOP-24 package compatibility with high-density PCB layouts.
Technical Context
The UC5612PWP implements a precision active termination architecture for SCSI parallel buses, using internal trimming to achieve ±5% matching on both output impedance and sinking current - critical for maintaining signal integrity under fast SCSI timing constraints. Its DISCNCT-controlled high-impedance disconnect mode disables all termination channels and the regulator simultaneously.
Thermal shutdown (170 °C) and current limiting protect against overloads during bus contention or short circuits. The device operates across 3.8–5.25 V TRMPWR and delivers regulated 2.8 V (±0.2 V) from its REG pin, supporting termination without external regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Termination Channels | 9 independent 110-Ω lines with ±5% impedance tolerance - ensures consistent bus termination per SCSI-2 spec. |
| Sinking Current | −21.5 mA typical per channel at 0.5 V line voltage - meets active negation requirement for SCSI signal integrity. |
| Output Capacitance | 5 pF (TSSOP package) - minimizes capacitive loading on SCSI bus nodes to preserve edge rates. |
| Regulator Output | 2.8 V ±0.2 V with 1.2 V dropout - powers internal circuitry and supports stable termination under varying input conditions. |
| Disconnect Supply Current | 100 µA max - enables ultra-low-power standby when DISCNCT is high or open. |
| Thermal Shutdown | 170 °C with 10 °C hysteresis - prevents latch-up or damage during sustained overload or poor heatsinking. |
| Signal Voltage Range | 0–5.0 V - compatible with TTL/CMOS logic levels on SCSI data/control lines. |
Pinout & Package
TSSOP-24 (PW) package with exposed thermal pad; low thermal resistance design supports 2 W continuous operation. Ground pins distributed across multiple locations (pins 5, 6, 7, 8, 17, 18, 19, 20) for optimal heat dissipation and signal return path integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| DISCNCT (Pin 6) | Logic control input | High or open state disconnects all 9 termination channels and disables regulator - reduces supply current to 100 µA. |
| TRMPWR (Pin 11) | Main power input | Accepts 3.8–5.25 V supply; powers regulator and termination circuitry - must be decoupled locally. |
| REG (Pin 14) | Regulated output | Provides 2.8 V ±0.2 V for internal biasing; can source up to 400 mA sink current for external loads. |
| LINE1–LINE9 (Pins 1,2,3,7,8,9,10,15,16) | Termination outputs | Each drives 110-Ω termination to GND; sinks −21.5 mA at 0.5 V - implements active negation per SCSI standard. |
| GND (Pins 5,6,7,8,17,18,19,20) | Ground reference | Multiple dedicated ground terminals minimize IR drop and improve noise immunity across high-current switching paths. |
Key Features
| Feature | Design Value |
|---|---|
| SCSI Hot-Plug Compliance | Guaranteed via 5-pF channel capacitance and controlled disconnect behavior - prevents bus glitches during live insertion/removal. |
| Trimmed Termination Accuracy | ±5% impedance and current matching - maximizes noise margin in fast SCSI (10 MB/s) and ultra SCSI (20 MB/s) modes. |
| Integrated Regulator | 1-V dropout, 2.8-V output with thermal shutdown - eliminates need for external LDO in compact SCSI designs. |
| Low-Power Disconnect Mode | 100-µA quiescent current with all channels in high-Z - enables power gating in idle or suspend states. |
| Thermal Protection | 170 °C shutdown with 10 °C hysteresis - prevents thermal runaway during sustained bus contention or short-circuit faults. |
Applications
| Narrow SCSI Bus Termination | Wide SCSI Bus Termination |
|---|---|
Use Scenario: Termination of 8-bit SCSI-2 bus in servers, workstations, or RAID controllers where one endpoint requires active termination. IC Role / Device Role / Timing Role: Provides nine 110-Ω termination paths with active negation and regulated bias - fulfills SCSI-2 requirement for dual-end termination. Use Value: Enables reliable 10 MB/s data transfer by maintaining controlled impedance and minimizing reflections on stubbed bus topologies. |
Use Scenario: Termination of 16-bit wide SCSI bus in high-performance storage subsystems requiring three UC5612 devices (two at ends, one mid-bus). IC Role / Device Role / Timing Role: Supplies matched 110-Ω termination across all data/control lines while supporting hot-plug detection via DISCNCT signaling. Use Value: Achieves 20 MB/s ultra-SCSI timing margins through ±5% current/impedance matching and sub-5-pF node capacitance. |
| SCSI Hot-Plug Systems | Legacy Storage Interface Boards |
Use Scenario: Backplane-based SCSI enclosures where drives are inserted/removed while system is powered. IC Role / Device Role / Timing Role: Enters high-Z disconnect mode upon hot-insertion detection - isolates bus segments until full initialization completes. Use Value: Prevents signal corruption and bus lockup during live reconfiguration by eliminating transient loading during connector mating. |
Use Scenario: Retrofitting SCSI termination on industrial embedded boards lacking on-board regulators or precision resistors. IC Role / Device Role / Timing Role: Replaces discrete resistor networks and Zener-based regulators with single-chip solution - simplifies BOM and layout. Use Value: Reduces component count by >12 parts per termination point while improving long-term drift stability via laser-trimmed elements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCSI active termination applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC5603PWP | Includes negative clamps on outputs; ±3% impedance/current tolerance vs. UC5612PWP's ±5% | Required for legacy SCSI implementations mandating clamp diodes for overvoltage protection | Select UC5603PWP only if negative clamping is explicitly required by host controller or bus specification |
| AMCC 53CF94 | Single-chip SCSI-2 controller + terminator; no standalone termination capability; different pinout and interface | Used in embedded SCSI host adapters - not a drop-in replacement for termination-only use cases | Choose AMCC 53CF94 only when integrating controller + terminator; UC5612PWP remains preferred for pure termination upgrades |
Compared with UC5603PWP and AMCC 53CF94, the UC5612PWP offers optimized cost and simplicity for dedicated SCSI termination where negative clamping is unnecessary and controller integration is undesired - delivering precise 110-Ω matching and ultra-low disconnect current in a space-efficient TSSOP-24 package.
Availability
UC5612PWP is available at Aetrix Electronics and suitable for narrow SCSI bus termination, wide SCSI bus termination, and SCSI hot-plug systems requiring stable component supply and long-lifecycle support for legacy industrial storage designs.
Supply support for UC5612PWP 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 leader specializing in analog, embedded processing, and connectivity technologies - serving industrial, automotive, communications, and computing markets since 1930.
The UC5612PWP belongs to TI's legacy SCSI interface product line, designed specifically to simplify robust, standards-compliant termination for parallel SCSI-2 and SPI-2 bus architectures in enterprise and industrial storage systems.
FAQ
What is the primary function of the UC5612PWP in a SCSI system?
The UC5612PWP provides nine channels of precision active termination for SCSI parallel buses, delivering 110-Ω impedance with ±5% tolerance and −21.5-mA sinking current per channel. It integrates a 2.8-V regulator and DISCNCT-controlled disconnect mode, enabling compliant termination at both ends of narrow or wide SCSI-2 bus segments - directly supporting SCSI-2 and SPI-2 standards without external components. The UC5612PWP is essential for maintaining signal integrity and noise margin in fast SCSI operation.
How does the DISCNCT pin affect UC5612PWP operation?
When the DISCNCT pin (Pin 6) is driven high or left open, the UC5612PWP places all nine termination channels into high-impedance state and disables its internal 2.8-V regulator, reducing supply current to ≤100 µA. This disconnect mode is critical for SCSI hot-plug functionality and low-power standby. A low DISCNCT signal enables normal termination operation. The UC5612PWP's DISCNCT logic is referenced to GND and accepts 0–6 V input, ensuring robust interfacing with TTL/CMOS controllers.
What package type and thermal characteristics does the UC5612PWP use?
The UC5612PWP is packaged in a 24-pin TSSOP (PW) with eight dedicated ground pins (5, 6, 7, 8, 17, 18, 19, 20) and an exposed thermal pad for enhanced heat dissipation. Its low thermal resistance design supports continuous 2 W operation - verified in TI's custom power packages. The device includes thermal shutdown at 170 °C with 10 °C hysteresis, protecting against overheating during bus contention or inadequate PCB copper area. This thermal performance makes the UC5612PWP suitable for dense, fanless storage enclosures.
Does the UC5612PWP require external components for basic operation?
No, the UC5612PWP operates autonomously with only TRMPWR (3.8–5.25 V), GND, and DISCNCT connections. Its integrated 2.8-V regulator eliminates the need for external LDOs, and laser-trimmed impedance/current remove reliance on precision external resistors. A single 0.1-µF ceramic capacitor on TRMPWR is recommended for local decoupling. The UC5612PWP's self-contained architecture reduces BOM count and layout complexity compared to discrete termination solutions - making it ideal for retrofitting legacy SCSI interfaces.
What is the significance of 5-pF output capacitance in the UC5612PWP?
The UC5612PWP's 5-pF channel capacitance (measured on TSSOP package) minimizes loading on SCSI bus nodes, preserving signal edge rates and reducing distortion during high-speed transfers (up to 20 MB/s in wide SCSI). This low capacitance prevents excessive RC time constants that could degrade setup/hold timing margins - especially critical at bus stubs or connectors. Unlike higher-capacitance alternatives, the UC5612PWP maintains signal integrity without requiring additional bus repeaters or equalization. This parameter is validated per SLUS164A and applies directly to the UC5612PWP in TSSOP-24 configuration.
UC5612PWP 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:
- -
UC5612PWP FAQ
1.How can I place an order for UC5612PWP through Aetrix?
Please submit a Request for Quotation (RFQ) for UC5612PWP 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 UC5612PWP reliable?
The price and inventory of UC5612PWP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC5612PWP is usually 5 days.
3.What payment methods are accepted for UC5612PWP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC5612PWP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC5612PWP?
UC5612PWP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC5612PWP 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 UC5612PWP?
For technical support, including UC5612PWP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC5612PWP requirements.
6.How does Aetrix verify that UC5612PWP is sourced from the original manufacturer or authorized distributors?
All UC5612PWP 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 UC5612PWP meets industry standards.
7.What is the process for return or replacement of UC5612PWP?
All UC5612PWP units undergo pre-shipment inspection (PSI). If there is an issue with UC5612PWP, 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 UC5612PWP part is unused and in its original packaging.
Return procedure for UC5612PWP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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