My Inquiry
My Account
Texas Instruments UC5603QP
- Part No.:
- UC5603QP
- Manufacturer:
- Texas Instruments
- Category:
- Signal Terminators
- Package:
- -
- Datasheet:
-
UC5603QP.pdf
- Description:
- SCSI TERMINATOR, 9-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:777
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UC5603QP from Texas Instruments is a 9-channel active SCSI termination IC designed for Wide SCSI parallel bus endpoints. It delivers trimmed 110-Ω termination impedance (±3%), 6-pF channel capacitance, and ±400-mA sink/source capability - enabling hot-pluggable, low-noise termination in high-speed SCSI-2 and SPI-2 systems.
For engineers reviewing the UC5603QP datasheet, UC5603QP pinout, UC5603QP application, or UC5603QP equivalent, key selection criteria include its PLCC-28 package thermal performance, disconnect-controlled standby current (100 µA), regulator-stabilized 2.9-V output, and negative clamping on all nine signal lines for latch-up protection.
Technical Context
The UC5603QP integrates a precision 2.9-V linear regulator with ≤50-mV load regulation and 1-V dropout, powering nine matched termination channels. Each channel features independently trimmed impedance (107–113 Ω) and current (−21.9 mA typical at 0.5 V), meeting SCSI-2 active termination spec limits.
Its DISCNCT input enables logic-controlled full-bus disconnect: opening the input disables regulator output and places all LINEx pins in high-impedance state, reducing supply current to 100 µA while maintaining signal integrity via 6-pF capacitance per channel.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Termination Channels | 9 independent SCSI signal lines (LINE1–LINE9) |
| Termination Impedance | 110 Ω ±3% - trimmed for noise margin compliance in Fast/Wide SCSI |
| Channel Capacitance | 6 pF typical - minimizes signal distortion at interim bus positions |
| Regulator Output | 2.9 V ±0.1 V - stable reference for termination bias under 100–400 mA load |
| Disconnect Current | 100 µA max - enables ultra-low-power standby during hot-plug events |
| Signal Clamp Level | −0.05 V typical - protects external drivers from negative transients |
| Thermal Shutdown | 170 °C with 10 °C hysteresis - prevents damage during sustained overload |
Pinout & Package
UC5603QP is housed in a 28-pin PLCC (FN) package with J-lead construction, optimized for thermal dissipation in 1.2-W operation. Pin 1 marked by corner notch; seating plane defined per JEDEC MS-018.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–9, 11–19 (LINE1–LINE9) | Termination Output | Active-low SCSI signal terminators; each sinks −22 mA at 0.5 V |
| 10 | DISCNCT | Logic input: high = disconnect all terminators + disable regulator |
| 20 | REG | Regulator output - supplies bias to all termination channels |
| 21–24, 26–28 | GND / SGND | Signal and power ground returns; multiple pins reduce ground bounce |
| 25 | TRMPWR | Main termination power input (3.8–5.25 V); powers internal regulator |
Key Features
| Feature | Design Value |
|---|---|
| Trimmed termination current | ±3% tolerance ensures maximum noise margin in Fast SCSI timing windows |
| Negative clamping on all lines | −0.05 V clamp threshold prevents latch-up of external SCSI drivers |
| Low-channel capacitance | 6 pF per line preserves signal edge rate on long or branched SCSI buses |
| Hot-plug compliant disconnect | DISCNCT input meets SCSI hot-plug specification for safe insertion/removal |
| Thermal shutdown protection | 170 °C trip with 10 °C hysteresis maintains reliability under sustained overload |
Applications
| Wide SCSI Host Adapter | SCSI Backplane Termination |
|---|---|
|
Use Scenario: Termination at host controller end of a 16-bit Wide SCSI bus supporting up to 16 devices. IC Role / Device Role / Timing Role: Active termination IC providing regulated 2.9-V bias and matched 110-Ω loads on all 9 signal lines. Use Value: Eliminates passive resistor networks, reduces board space by 40%, and improves noise margin by 3 dB over untrimmed alternatives. |
Use Scenario: Mid-bus termination on a multi-slot SCSI backplane where stubs exceed 0.1 m. IC Role / Device Role / Timing Role: High-impedance-disconnectable terminator enabling dynamic bus reconfiguration without power cycle. Use Value: 6-pF channel capacitance prevents signal reflections at >10 MB/s transfer rates; DISCNCT allows runtime bus segmentation. |
| RAID Controller Module | Legacy Storage Enclosure |
|
Use Scenario: Dual-terminated RAID controller card requiring hot-swap support for drive bays. IC Role / Device Role / Timing Role: Endpoint terminator with thermal shutdown and negative clamping for robust field operation. Use Value: −400-mA sinking capability handles worst-case SCSI negation current; 100-µA disconnect mode extends system standby life. |
Use Scenario: Retrofit termination for aging SCSI-2 storage enclosures lacking active termination. IC Role / Device Role / Timing Role: Drop-in replacement for obsolete UC5601/UC5602 with identical pin-compatible PLCC footprint. Use Value: 3% impedance trim matches legacy bus timing budgets; PLCC-28 package fits existing sockets without PCB redesign. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCSI active termination applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC5603DP | SOIC-16 package; same electrical specs but higher thermal resistance (θJA ≈ 120°C/W vs. PLCC's 85°C/W) | Suitable for lower-power or ambient-cooled designs; not socket-compatible with PLCC-28 footprints | Select UC5603DP only if board layout uses SOIC-16 and thermal budget permits 1.2-W dissipation |
| AMCC 53CF94 | Integrated SCSI protocol controller + termination; no discrete REG/TERMPWR separation; 3.3-V only | Replaces both controller and terminator; requires full firmware and interface redesign | Choose AMCC 53CF94 only when migrating from discrete termination to integrated controller architecture |
Compared with UC5603DP and AMCC 53CF94, the UC5603QP uniquely combines PLCC-28 socket compatibility, 5-V tolerant operation, and standalone termination functionality - making it the only direct replacement for legacy PLCC-based SCSI termination designs without layout or voltage rail changes.
Availability
UC5603QP is available at Aetrix Electronics and suitable for Wide SCSI host adapters, RAID controller modules, and legacy storage enclosure retrofits requiring stable component supply and long-term obsolescence management.
Supply support for UC5603QP 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 with over 50 years of innovation in industrial and computing interfaces.
The UC5603QP belongs to TI's legacy SCSI interface product line, engineered specifically for high-reliability, hot-pluggable parallel bus termination in enterprise storage and industrial computing systems.
FAQ
What is the primary function of the UC5603QP in a SCSI system?
The UC5603QP serves as a 9-channel active terminator for Wide SCSI parallel buses, providing precision 110-Ω termination impedance, regulated 2.9-V bias, and logic-controlled disconnect. It replaces passive resistor networks to improve noise margin and enable hot-plug operation - critical for reliable endpoint termination in UC5603QP-based SCSI-2 and SPI-2 implementations.
Does the UC5603QP support hot-plugging, and how is it implemented?
Yes, the UC5603QP fully supports SCSI hot-plugging via its DISCNCT input. When driven high, DISCNCT disconnects all nine termination lines and disables the internal regulator, reducing supply current to 100 µA. This allows safe insertion or removal of the UC5603QP-equipped board while the SCSI bus remains powered - a requirement verified in TI's SLUS195B datasheet.
What is the significance of the 6-pF channel capacitance specified for the UC5603QP?
The 6-pF typical channel capacitance of the UC5603QP minimizes loading on SCSI signal lines, preserving signal edge rates and reducing reflections - especially critical at Fast/Wide SCSI speeds (>10 MB/s). This low capacitance ensures that UC5603QP installations at interim bus positions do not degrade timing margins, directly supporting compliance with SCSI-2 signal integrity requirements.
How does the UC5603QP achieve its ±3% termination impedance tolerance?
The UC5603QP achieves ±3% termination impedance through on-die laser trimming during final test - a process explicitly documented in the SLUS195B datasheet. This trimming is applied after regulator calibration and ensures each of the nine termination channels matches the target 110-Ω value within 3%, maximizing noise margin in high-speed SCSI operation - a key differentiator of the UC5603QP versus untrimmed alternatives.
Is the UC5603QP still in production, and what packaging options are available?
The UC5603QP is marked "OBSOLETE" by Texas Instruments per its official packaging addendum, with last-time-buy status. Aetrix Electronics maintains legacy inventory and traceable sourcing for the PLCC-28 (FN) package variant. No SOIC or PDIP variants exist for UC5603QP - only the PLCC-28 configuration was manufactured, and it remains the sole valid package for this specific part number.
UC5603QP 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:
- -
UC5603QP FAQ
1.How can I place an order for UC5603QP through Aetrix?
Please submit a Request for Quotation (RFQ) for UC5603QP 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 UC5603QP reliable?
The price and inventory of UC5603QP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC5603QP is usually 5 days.
3.What payment methods are accepted for UC5603QP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC5603QP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC5603QP?
UC5603QP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC5603QP 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 UC5603QP?
For technical support, including UC5603QP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC5603QP requirements.
6.How does Aetrix verify that UC5603QP is sourced from the original manufacturer or authorized distributors?
All UC5603QP 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 UC5603QP meets industry standards.
7.What is the process for return or replacement of UC5603QP?
All UC5603QP units undergo pre-shipment inspection (PSI). If there is an issue with UC5603QP, 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 UC5603QP part is unused and in its original packaging.
Return procedure for UC5603QP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UC5603QP Tags
-
LTC1344IG#PBF
Analog Devices Inc.
-
LTC1344AIG#PBF
Analog Devices Inc.
-
UCC5672PWP
Texas Instruments
-
LTC1344ACG#PBF
Analog Devices Inc.
-
MXL1344ACAG+
Analog Devices Inc./Maxim Integrated
-
LTC1344CG#PBF
Analog Devices Inc.
-
PACUSB-U3R
onsemi
-
PACUSB-D1Y5R
onsemi
-
FAN1804MCX
Fairchild Semiconductor
-
MCCS142237DT
onsemi
-
MCCS142237DTR2
onsemi
-
UCC5519PWPR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
