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Texas Instruments UCC5640PWX
- Part No.:
- UCC5640PWX
- Manufacturer:
- Texas Instruments
- Category:
- Signal Terminators
- Package:
- -
- Datasheet:
-
UCC5640PWX.pdf
- Description:
- SCSI TERMINATOR, 9-LINE, 105OHM
- Quantity:
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Inventory:1,275
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Product details
Overview
UCC5640PWX from Texas Instruments is a low-voltage differential (LVD) SCSI active terminator IC designed for Ultra2, Ultra3/Ultra160, and Ultra320 bus compliance. It provides 105 Ω differential termination impedance, 150 Ω common-mode impedance, and 56 mV line biasing with 1.25 V regulated common-mode voltage. Operates from 2.7 V to 5.25 V and supports automatic LVD/SE/HVD mode detection via DIFFB/DIFSENS interface - used in high-speed server backplanes and storage subsystems.
For engineers reviewing the UCC5640PWX datasheet, UCC5640PWX pinout, UCC5640PWX application, or UCC5640PWX equivalent, key selection criteria include LVD-only termination capability, differential bias stability under bus loading, TRMPWR supply current in active/disabled states, and compatibility with TSSOP-24 layout constraints for multi-terminator SCSI implementations.
Technical Context
The UCC5640PWX implements dual-regulator architecture: a 1.25 V regulator for LVD termination bias and a 1.3 V regulator for DIFSENS line driving. Its mode detection logic interprets DIFFB voltage thresholds (0.7–1.9 V for LVD; <0.5 V or >2.4 V for SE/HVD) to switch termination networks on/off without external control.
Termination is applied across nine differential pairs (L1± to L9±), each presenting matched 105 Ω differential impedance and 150 Ω common-mode impedance. The device features 1.5 pF channel capacitance per signal path and 3 pF output capacitance to ground - critical for Ultra320's 6.5 pF trace-to-trace limit.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Differential Impedance | 105 Ω ±5 Ω - matches Ultra320 specification for minimal signal reflection on 120-Ω differential traces |
| Common-Mode Impedance | 150 Ω - ensures stable 1.25 V bias point across all differential pairs under load |
| Line Bias Voltage | ±56 mV around 1.25 V - maintains valid LVD logic levels during idle bus states |
| TRMPWR Supply Range | 2.7 V to 5.25 V - supports 3.3 V systems with ±10% tolerance and cable drop margin |
| Supply Current (Active) | 25 mA - enables three devices per end (27-line termination) within 1 W package dissipation limit |
| Output Capacitance | 3 pF - meets Ultra320 max 6.5 pF trace-to-trace requirement with tight inter-pair matching (≤0.3 pF) |
| Mode Detection Thresholds | 0.7–1.9 V (LVD), <0.5 V (SE), >2.4 V (HVD) - accommodates ground potential shifts up to 200 mV on long buses |
Pinout & Package
UCC5640PWX is packaged in a 24-pin TSSOP (PW) with 0.65 mm pitch, 7.8 mm × 4.4 mm body, and exposed thermal pad (not electrically connected). Pin 1 is marked by a dot; pin numbering follows standard TSSOP top-view convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| TRMPWR (24) | Power input | 2.7–5.25 V supply; powers regulators and termination network; requires 4.7 µF + 0.01 µF decoupling |
| REG (1) | Regulator bypass | Connects to 4.7 µF capacitor to ground; stabilizes 1.25 V regulator output for precise biasing |
| DIFFB (10) | Differential sense filter | Monitors DIFFSENS line voltage; internal comparator determines LVD/SE/HVD mode; connects to 4.7 µF cap + 50 kΩ resistor |
| DIFSENS (11) | Differential sense driver | Drives DIFFSENS line to 1.3 V in LVD mode; disabled in SE/HVD mode; only one device per bus end should drive this line |
| DISCNCT (13) | Terminator disable control | High-level input disables all termination resistors and regulators; reduces supply current to 400 µA for power savings |
| GND (12) | Ground reference | Primary return path for regulators, termination, and sense circuitry; must be low-impedance plane connection |
| L1+ to L9+ (pins 2–9, 14–17, 20–23) | Differential positive inputs | Accept SCSI LVD signal pairs; each pair terminated with 105 Ω differential / 150 Ω common-mode network |
| L1− to L9− (pins 3–10, 15–18, 21–24 except TRMPWR) | Differential negative inputs | Paired with corresponding Lx+ pins; matched routing required to maintain ≤0.1 pF intra-pair capacitance delta |
Key Features
| Feature | Design Value |
|---|---|
| LVD-only active termination | Eliminates SE/HVD termination components; prevents bus contention when mixed-driver systems are detected |
| Auto-sensing mode detection | Uses DIFFB voltage thresholds to switch between LVD (105 Ω), SE/HVD (high-Z), and disconnect (0 µA) states without host intervention |
| Ultra320-compliant impedance | 105 Ω differential + 150 Ω common-mode impedance meets SPI-4 spec; 3 pF output capacitance enables >320 MB/s data rates |
| Low bus loading | 1.5 pF channel capacitance per line pair minimizes signal integrity degradation on dense backplane layouts |
| Power-aware disconnect | DISCNCT input shuts down both regulators and termination network, reducing supply current from 25 mA to 400 µA |
Applications
| Server Backplane Termination | RAID Controller Interface |
|---|---|
Use Scenario: Termination of dual-ported Ultra320 SCSI buses connecting RAID controllers to disk enclosures in 1U/2U rack servers. IC Role / Device Role / Timing Role: Active Y-terminator providing matched 105 Ω differential impedance and 1.25 V common-mode bias at both bus ends. Use Value: Enables full 320 MB/s throughput by meeting Ultra320's 13 pF trace-to-ground and 6.5 pF trace-to-trace capacitance limits with <0.3 pF inter-pair skew. |
Use Scenario: High-reliability termination in embedded RAID-on-motherboard (ROMB) designs where space-constrained TSSOP-24 placement is required. IC Role / Device Role / Timing Role: LVD-only terminator with auto-detection that isolates bus from SE/HVD legacy drives during hot-swap events. Use Value: Prevents bus lockup during mixed-drive insertion by entering high-impedance SE/HVD state within 100 ns of DIFFB threshold violation. |
| Storage Array Interconnect | Tape Library Host Interface |
Use Scenario: Multi-terminator configuration (three UCC5640PWX per end) terminating 27-line Ultra160 SCSI buses in enterprise storage arrays. IC Role / Device Role / Timing Role: One device drives DIFSENS; others monitor DIFFB - coordinated mode selection across all terminators at each bus end. Use Value: Ensures consistent LVD activation across all 27 lines using shared 50-kΩ/4.7-µF DIFFB filter, eliminating timing skew in mode transitions. |
Use Scenario: Termination of SCSI buses linking tape libraries to backup servers operating in mixed LVD/SE environments. IC Role / Device Role / Timing Role: Fail-safe terminator that enters high-Z state if any SE device is detected, preserving bus integrity without manual reconfiguration. Use Value: Eliminates need for jumper-based termination selection; supports seamless migration from Ultra2 to Ultra160 infrastructure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCSI active termination applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AMCC 5640A | Pin-compatible 24-pin TSSOP; identical 105 Ω/150 Ω impedance but higher 40 mA active supply current | Valid for Ultra320 but requires larger decoupling due to higher noise sensitivity on DIFSENS line | Select when legacy AMCC-based designs require drop-in replacement with verified layout reuse |
| ICS83021AGI | Single-chip 28-pin solution supporting both LVD and SE termination; lacks auto-sensing - requires external mode control | Suitable for new designs needing mixed-mode flexibility but adds GPIO overhead and PCB real estate | Choose only if system firmware can manage mode selection; not recommended for pure LVD Ultra320 deployments |
Compared with AMCC 5640A and ICS83021AGI, the UCC5640PWX delivers lower power consumption (25 mA vs. 40 mA), tighter capacitance control (3 pF vs. 5 pF), and autonomous mode switching - making it optimal for space- and power-constrained Ultra320 backplanes where reliability trumps configurability.
Availability
UCC5640PWX is available at Aetrix Electronics and suitable for server backplane termination, RAID controller interfaces, and storage array interconnects requiring stable component supply across extended product lifecycles.
Supply support for UCC5640PWX 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, specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and computing markets.
The UCC5640PWX belongs to TI's SCSI interface product line, engineered specifically for high-speed differential bus termination in enterprise storage systems compliant with SPI-2 through SPI-4 standards.
FAQ
What is the primary function of the UCC5640PWX in a SCSI system?
The UCC5640PWX serves as a low-voltage differential (LVD) active terminator for SCSI buses, providing precise 105 Ω differential and 150 Ω common-mode termination impedance while automatically detecting bus mode (LVD, SE, or HVD) via the DIFFB/DIFSENS interface. Its role is to maintain signal integrity at Ultra320 speeds by minimizing reflections and ensuring stable common-mode bias at 1.25 V - critical for reliable operation of the UCC5640PWX in server and storage applications.
Does the UCC5640PWX support single-ended (SE) or high-voltage differential (HVD) SCSI buses?
No, the UCC5640PWX is explicitly designed for LVD-only operation and is not intended for use in SE or HVD systems. When SE or HVD drivers are detected via the DIFFB input voltage (below 0.5 V or above 2.4 V), the UCC5640PWX switches its termination network to high-impedance state, effectively disconnecting from the bus. This behavior is documented in the UCC5640PWX datasheet and ensures safe coexistence with legacy SCSI hardware without risking bus contention.
How many UCC5640PWX devices are needed to terminate a full Ultra320 SCSI bus?
Three UCC5640PWX devices are required at each end of the Ultra320 SCSI bus to terminate all 27 signal lines (18 data + 9 control). Each UCC5640PWX handles nine differential pairs (L1± to L9±). Only one of the three devices at each end drives the DIFSENS line; the others monitor DIFFB to synchronize mode selection - a configuration validated in the UCC5640PWX application diagram and essential for correct UCC5640PWX operation in multi-terminator setups.
What is the purpose of the DISCNCT pin on the UCC5640PWX?
When the DISCNCT pin is driven high, the UCC5640PWX disables its termination resistors and shuts down both the 1.25 V and 1.3 V regulators, reducing TRMPWR supply current from 25 mA to 400 µA. This feature allows dynamic power management during bus idle periods or when the terminator is not at the physical end of the SCSI chain. The UCC5640PWX retains mode-detection functionality even in disconnect mode, ensuring rapid reactivation when needed - a key capability for energy-efficient UCC5640PWX deployment.
Can the UCC5640PWX be used with 5 V supply rails?
Yes, the UCC5640PWX supports TRMPWR supply voltages from 2.7 V to 5.25 V, making it compatible with both 3.3 V and 5 V systems. In 5 V operation, the internal regulators maintain their specified 1.25 V and 1.3 V outputs, and termination impedance remains stable at 105 Ω/150 Ω. However, thermal considerations require verification of package dissipation (max 1 W) under full-load conditions - a constraint explicitly defined for the UCC5640PWX in its absolute maximum ratings table.
UCC5640PWX 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:
- -
UCC5640PWX FAQ
1.How can I place an order for UCC5640PWX through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC5640PWX 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 UCC5640PWX reliable?
The price and inventory of UCC5640PWX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC5640PWX is usually 5 days.
3.What payment methods are accepted for UCC5640PWX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC5640PWX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC5640PWX?
UCC5640PWX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC5640PWX 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 UCC5640PWX?
For technical support, including UCC5640PWX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC5640PWX requirements.
6.How does Aetrix verify that UCC5640PWX is sourced from the original manufacturer or authorized distributors?
All UCC5640PWX 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 UCC5640PWX meets industry standards.
7.What is the process for return or replacement of UCC5640PWX?
All UCC5640PWX units undergo pre-shipment inspection (PSI). If there is an issue with UCC5640PWX, 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 UCC5640PWX part is unused and in its original packaging.
Return procedure for UCC5640PWX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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