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Analog Devices Inc./Maxim Integrated DS2119ME+T&R
- Part No.:
- DS2119ME+T&R
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Signal Terminators
- Package:
- 28-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
DS2119ME+T&R.pdf
- Description:
- IC TERM SCSI LVD/SE ULT3 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,422
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Product details
Overview
DS2119ME+T&R from Maxim Integrated is a multimode Ultra3 LVD/SE SCSI bus terminator IC supporting SPI-2 through SPI-4, Ultra160, and Ultra320 standards. It provides auto-sensing termination for nine signal line pairs with 5% resistor tolerance, 3pF power-down capacitance, and on-board thermal shutdown. It enables hot-plug-compatible SCSI bus design in storage subsystems requiring backward compatibility with legacy SE devices.
For engineers reviewing the DS2119ME+T&R datasheet, DS2119ME+T&R pinout, DS2119ME+T&R application, or DS2119ME+T&R equivalent, key selection factors include its dual-mode (LVD/SE) auto-selection logic, DIFFSENSE trinary voltage decoding, precision 110Ω SE / 105Ω differential LVD termination, thermal isolation behavior, and TSSOP-28 packaging for high-density SCSI backplanes.
Technical Context
The DS2119ME+T&R implements trinary DIFFSENS voltage detection (SE: <0.6V, HVD: >2.15V, LVD: 0.7–1.9V) to autonomously select termination mode. Its internal bandgap reference generates 1.25V (LVD) and 2.85V (SE) references, switching resistor networks and current sources accordingly.
In LVD mode, it delivers 105Ω differential and 150Ω common-mode impedance with 112mV fail-safe bias; in SE mode, it maintains 110Ω termination while sourcing 25.4mA per line and regulating at 2.85V ±0.15V. ISO pin enables bus isolation during thermal shutdown or manual disable.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LVD Termination Resistance | 100–110Ω differential; ensures impedance matching for Ultra320 differential signaling integrity |
| SE Termination Resistance | 104.5–115.5Ω; tight 5% tolerance supports stable single-ended SCSI-3 termination |
| VREF Output Voltage | 2.85V (SE), 1.25V (LVD); precision references drive termination networks without external regulators |
| DIFFSENSE Input Range | SE: −0.3–0.5V, LVD: 0.7–1.9V, HVD: 2.4–VTPWR+0.3V; enables robust trinary bus-mode detection |
| Power-Down Capacitance | 3pF; minimizes signal reflection and timing skew on high-speed SCSI bus lines |
| Thermal Shutdown Threshold | 150°C; isolates termination pins and disables VREF to protect bus integrity under overtemperature |
| TPWR Operating Range | SE: 4.0–5.5V, LVD: 2.7–5.5V; supports mixed-voltage SCSI backplane power domains |
Pinout & Package
DS2119ME+T&R is housed in a RoHS-compliant 28-pin TSSOP (0.173" wide) package with exposed heat sink ground pad. Pin 6 and Pin 22 are internally connected to the mounting pad and must be soldered to PCB ground for thermal and EMI performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VREF (Pin 1) | Reference voltage output | Supplies 2.85V (SE) or 1.25V (LVD) to termination network; requires 4.7µF decoupling |
| RxP/RxN (Pins 2–5,7–12,18–21,23–26) | Signal termination terminals | Connect directly to SCSI bus signal pairs (e.g., D0P/D0N); nine differential or SE lines supported |
| HS GND (Pins 6,22) | Heat sink ground | Internal connection to exposed thermal pad; must be grounded for thermal dissipation and noise control |
| ISO (Pin 13) | Termination isolation control | High = disconnects RxP/RxN from bus while keeping VREF active; used for dynamic bus reconfiguration |
| GND (Pin 14) | Signal ground reference | Primary 0V return for analog and digital circuitry; separate from HS GND but tied at system ground |
| MSTR/SLV (Pin 15) | DIFFSENSE driver enable | High = enables DS2119ME+T&R to drive SCSI DIFFSENS line; required for master-mode bus arbitration |
| DIFFSENSE (Pin 16) | DIFFSENS bus output | Drives SCSI DIFFSENS line at 1.2–1.4V when MSTR/SLV = 1; indicates bus mode to other terminators |
| DIFF_CAP (Pin 17) | Differential sense filter input | Accepts 0.1µF capacitor to suppress high-frequency transients on DIFFSENS line; eliminates external RC filter |
| TPWR (Pins 27,28) | Termination power input | Connects to SCSI TERMPWR; requires local 2.2µF + 0.01µF decoupling for stable LVD/SE operation |
Key Features
| Feature | Design Value |
|---|---|
| Auto-select LVD/SE termination | Eliminates manual configuration by sensing DIFFSENS voltage level-no firmware or external logic needed |
| Trinary DIFFSENS decoding | Distinguishes SE (<0.6V), LVD (0.7–1.9V), and HVD (>2.15V) bus modes with integrated comparators and NAND logic |
| Fail-safe LVD bias | Maintains 112mV differential bias when no drivers are active-prevents floating bus states in Ultra320 systems |
| Active SE termination | Sinks 25.4mA per line while holding 2.85V reference within ±100mV-supports fast active-negation SCSI drivers |
| Integrated thermal shutdown | At 150°C, isolates RxP/RxN pins and places VREF in high-impedance-preserves bus functionality during fault conditions |
Applications
| SCSI Storage Backplane Termination | Hot-Pluggable RAID Controller Interface |
|---|---|
Use Scenario: Termination of wide Ultra320 SCSI buses in enterprise disk array enclosures with mixed LVD and SE drives. IC Role / Device Role / Timing Role: Dual-mode active terminator that auto-selects LVD or SE based on bus composition and maintains impedance continuity during drive insertion/removal. Use Value: Enables seamless interoperability between legacy SE peripherals and modern Ultra320 LVD storage without manual jumpering or redesign. | Use Scenario: Termination at the host adapter end of a hot-pluggable SCSI backplane in modular server storage bays. IC Role / Device Role / Timing Role: Bus-mode detector and termination enabler that asserts DIFFSENSE to coordinate multi-terminator arbitration during live insertion. Use Value: Guarantees correct termination mode activation within 100ms of device insertion, preventing bus lockup or data corruption. |
| Legacy SCSI-3 System Upgrade Path | Industrial Embedded SCSI Data Acquisition |
Use Scenario: Retrofitting older SE-only SCSI-3 systems with LVD-capable controllers while retaining existing cabling and peripherals. IC Role / Device Role / Timing Role: Adaptive terminator that defaults to SE mode when legacy devices dominate, then transitions to LVD when LVD-only segments are detected. Use Value: Extends system lifecycle by enabling incremental upgrades without full bus rewiring or component replacement. | Use Scenario: Termination of SCSI interfaces in ruggedized industrial data loggers using long cable runs and variable ambient temperatures. IC Role / Device Role / Timing Role: Thermally robust terminator with 0°C to +70°C operation and automatic isolation during overtemperature events. Use Value: Maintains SCSI signal integrity across −20°C to +85°C board-level environments via thermal shutdown and low-capacitance design. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCSI termination applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS2119M | No "+" marking; leaded (non-RoHS) version; identical electrical specs and pinout | Not suitable for new RoHS-compliant designs; requires Pb-containing solder process | Select DS2119M only for legacy repair or non-RoHS production environments |
| MAX3219ESE+ | Single-ended only; no LVD support; 28-pin SOIC package; lacks DIFFSENSE logic and thermal shutdown | Applicable only in fixed SE-only systems without hot-plug or mixed-mode requirements | Choose MAX3219ESE+ only when LVD capability, auto-detection, and thermal protection are unnecessary |
Compared with DS2119ME+T&R, DS2119M offers identical functionality but lacks RoHS compliance, while MAX3219ESE+ reduces cost and complexity at the expense of multimode flexibility, bus-mode arbitration, and thermal safety-making DS2119ME+T&R the sole choice for field-upgradeable, mixed-mode, or thermally demanding SCSI deployments.
Availability
DS2119ME+T&R is available at Aetrix Electronics and suitable for SCSI storage backplanes, RAID controller interfaces, and industrial data acquisition systems requiring stable component supply, RoHS compliance, and long-term obsolescence management.
Supply support for DS2119ME+T&R 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
Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.
The DS2119ME+T&R belongs to Maxim's SCSI interface product line, engineered specifically for reliable, multimode termination in mission-critical storage subsystems where backward compatibility, thermal resilience, and bus-mode autonomy are mandatory.
FAQ
What is the primary function of the DS2119ME+T&R in a SCSI system?
The DS2119ME+T&R serves as an intelligent multimode SCSI bus terminator that automatically selects between low-voltage differential (LVD) and single-ended (SE) termination based on real-time DIFFSENS voltage detection. It ensures signal integrity across Ultra160/Ultra320 buses by maintaining precise 105Ω (LVD) or 110Ω (SE) termination impedances, while supporting hot-plug operations and thermal fault protection-critical for enterprise storage backplanes where DS2119ME+T&R replaces manual jumper-based termination schemes.
How does the DS2119ME+T&R determine whether to use LVD or SE termination?
The DS2119ME+T&R uses its DIFF_CAP pin to monitor the SCSI bus DIFFSENS line and decode its voltage into one of three ranges: <0.6V (SE), 0.7–1.9V (LVD), or >2.15V (HVD). Internal comparators and logic switch the termination network accordingly-applying 1.25V reference and current-source-driven resistors for LVD mode, or 2.85V reference and 110Ω resistors for SE mode. This autonomous decision requires no external control, making DS2119ME+T&R ideal for dynamically configured SCSI environments.
What is the purpose of the ISO pin on the DS2119ME+T&R?
The ISO (Isolation) pin on the DS2119ME+T&R controls electrical disconnection between the device's RxP/RxN termination terminals and the SCSI bus. When ISO is driven high, the DS2119ME+T&R isolates its termination network while keeping VREF active-enabling safe bus reconfiguration, diagnostic testing, or partial system shutdown without disrupting reference stability. This feature is essential in modular storage systems where DS2119ME+T&R must support dynamic topology changes without signal corruption.
Does the DS2119ME+T&R require external passive components for basic operation?
Yes-the DS2119ME+T&R requires three mandatory external capacitors: a 4.7µF capacitor between VREF and ground for reference regulation, a 2.2µF capacitor plus a 0.01µF ceramic capacitor between each TPWR pin and ground for termination power filtering, and a 0.1µF capacitor on DIFF_CAP for noise suppression. These components are specified in the DS2119ME+T&R datasheet to ensure stable mode detection, low-noise termination, and immunity to high-frequency transients on the SCSI bus.
What thermal protection features does the DS2119ME+T&R provide?
The DS2119ME+T&R integrates a thermal shutdown circuit that triggers at 150°C. Upon activation, it electrically isolates all RxP/RxN termination pins from the SCSI bus and places the VREF output in high-impedance state-preserving bus signal integrity while preventing damage. The DIFFSENSE driver is also disabled during shutdown. This behavior is fully automatic and reversible; DS2119ME+T&R resumes normal operation once temperature falls below the hysteresis threshold, making it suitable for enclosed, fanless storage enclosures where DS2119ME+T&R operates continuously under load.
DS2119ME+T&R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- SCSI, LVD, SE
- Number of Terminations:
- 9
- Voltage - Supply:
- 4V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSSOP
DS2119ME+T&R FAQ
1.How can I place an order for DS2119ME+T&R through Aetrix?
Please submit a Request for Quotation (RFQ) for DS2119ME+T&R 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 DS2119ME+T&R reliable?
The price and inventory of DS2119ME+T&R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS2119ME+T&R is usually 5 days.
3.What payment methods are accepted for DS2119ME+T&R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS2119ME+T&R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS2119ME+T&R?
DS2119ME+T&R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS2119ME+T&R 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 DS2119ME+T&R?
For technical support, including DS2119ME+T&R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS2119ME+T&R requirements.
6.How does Aetrix verify that DS2119ME+T&R is sourced from the original manufacturer or authorized distributors?
All DS2119ME+T&R 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 DS2119ME+T&R meets industry standards.
7.What is the process for return or replacement of DS2119ME+T&R?
All DS2119ME+T&R units undergo pre-shipment inspection (PSI). If there is an issue with DS2119ME+T&R, 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 DS2119ME+T&R part is unused and in its original packaging.
Return procedure for DS2119ME+T&R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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