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Texas Instruments SN65ELT20DR
- Part No.:
- SN65ELT20DR
- Manufacturer:
- Texas Instruments
- Category:
- Translators, Level Shifters
- Package:
- Datasheet:
-
SN65ELT20DR.pdf
- Description:
- IC TRANSLTR UNIDIRECTIONAL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,676
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Product details
Overview
SN65ELT20DR from Texas Instruments is a 5-V TTL-to-differential PECL translator IC used for clock and data signal level conversion in high-speed backplane interfaces. It features 1.25-ns maximum propagation delay, operates from 4.2 V to 5.7 V, delivers PECL outputs (VOH = 3915–4120 mV, VOL = 3170–3380 mV) with 50-Ω termination to VCC – 2 V, and supports –40°C to +85°C industrial temperature range.
For engineers reviewing the SN65ELT20DR datasheet, SN65ELT20DR pinout, SN65ELT20DR application, or SN65ELT20DR equivalent, this device is selected for low-skew, flow-through-layout-compatible translation between single-ended TTL logic and differential PECL signaling in timing-critical infrastructure systems.
Technical Context
The SN65ELT20DR implements a single-channel unidirectional translation path: one TTL input drives complementary PECL outputs (Q and Q̅), with no internal feedback or enable control. Its output stage is designed for 50-Ω source termination into VCC – 2 V, ensuring consistent differential swing across temperature and supply voltage.
Propagation delay asymmetry (tPLH ≤ 1.25 ns, tPHL ≤ 1.2 ns) and sub-1 ps RMS jitter support precise edge alignment in clock distribution networks. Built-in temperature compensation maintains output voltage stability without external calibration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.2 V to 5.7 V - Enables robust operation across noisy 5-V rail tolerances without regulation. |
| Propagation Delay | ≤1.25 ns (tPLH), ≤1.2 ns (tPHL) - Ensures sub-nanosecond timing margin for ≥430-MHz switching. |
| Output Swing | VOH = 3915–4120 mV, VOL = 3170–3380 mV - Delivers 700–800 mVPP differential amplitude into 50-Ω load. |
| Input Thresholds | VIH = 2 V min, VIL = 0.8 V max - Compatible with standard TTL logic families without level-shifting. |
| Operating Temp | –40°C to +85°C - Qualified for industrial backplane and telecom equipment environments. |
| Max Frequency | 430 MHz - Supports high-speed serial clock/data transmission up to OC-48/STM-16 rates. |
| Power Supply Current | 9.6–10.7 mA - Low static consumption enables dense placement in multi-channel timing modules. |
Pinout & Package
SN65ELT20DR is housed in an industry-standard SOIC-8 (D) package, 3.9 mm × 4.9 mm body, 1.75 mm max height, with gull-wing leads and NiPdAu lead finish. Pin 1 is located at top-left corner (quadrant Q1) per tape-and-reel orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| D | TTL input | Single-ended logic input referenced to GND; must be driven - floating state yields undetermined output. |
| Q | PECL output (+) | True differential output; requires 50-Ω termination to VCC – 2 V for valid PECL logic levels. |
| Q̅ | PECL output (–) | Complementary differential output; paired with Q to form LVPECL-compatible differential pair. |
| VCC | Positive supply | 5-V power rail; also serves as reference for output termination voltage (VCC – 2 V). |
| GND | Ground | 0-V reference for TTL input thresholds and internal biasing; must be low-impedance. |
| NC | No-connect | Pins 1, 3, and 7 are internally unused; must remain unconnected per datasheet. |
Key Features
| Feature | Design Value |
|---|---|
| Flow-through pinout | Input (D) and outputs (Q/Q̅) placed on opposite sides - minimizes trace crossovers and reduces PCB routing complexity. |
| Built-in temperature compensation | Maintains stable VOH/VOL over –40°C to +85°C - eliminates need for external thermal drift correction circuits. |
| Drop-in compatibility | Pin- and function-compatible with MC10ELT20/MC100ELT20 - enables legacy design reuse without layout change. |
| Low output skew | <100 ps between Q and Q̅ edges - critical for maintaining differential integrity in clock distribution trees. |
| ESD protection | >4 kV HBM - meets industrial handling requirements without additional input protection circuitry. |
Applications
| Backplane Clock Distribution | High-Speed Data Link Interface |
|---|---|
|
Use Scenario: Distributing a single-board 100-MHz system clock across a 12-layer backplane to multiple line cards. IC Role / Device Role / Timing Role: Translates local TTL clock to differential PECL for noise-immune transmission over 30-cm FR4 traces. Use Value: Sub-1.25-ns delay and <100-ps Q/Q̅ skew preserve setup/hold margins across all receivers. |
Use Scenario: Converting parallel TTL data from an FPGA I/O bank to PECL for driving a 400-Mbps SerDes PHY interface. IC Role / Device Role / Timing Role: Unidirectional level shifter enabling interoperability between 3.3-V/5-V logic domains and differential signaling standards. Use Value: 430-MHz max frequency and 700-mVPP output swing meet AC-coupled PECL receiver sensitivity requirements. |
| Telecom Line Card Timing | Test Equipment Signal Conditioning |
|
Use Scenario: Generating synchronized PECL clocks for multiple DS3/E3 framers on a carrier-grade line card. IC Role / Device Role / Timing Role: Low-jitter (0.5 ps RMS) clock translator feeding fanout buffers in timing subsystems. Use Value: Built-in temperature compensation ensures stable duty cycle and amplitude across chassis thermal gradients. |
Use Scenario: Adapting bench-top function generator TTL outputs to drive PECL-input oscilloscope channels or bit-error-rate testers. IC Role / Device Role / Timing Role: Lab-grade signal conditioning IC providing repeatable, terminated PECL waveforms. Use Value: Flow-through layout and SOIC-8 footprint simplify prototyping; no external resistors required beyond termination. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TTL-to-PECL translation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC100ELT20DG | Same pinout, identical AC/DC specs, but rated for –40°C to +85°C with tighter propagation delay variation (±0.1 ns vs ±0.25 ns). | Preferred in aerospace-grade designs requiring tighter parametric consistency across temperature. | Select MC100ELT20DG when statistical timing margin analysis demands lower delay variance. |
| SN65LVDS100DR | LVDS output (not PECL); 3.3-V supply; 2.5-Gbps capability; different pinout and termination (100-Ω diff). | Suitable only where system uses LVDS receivers and 3.3-V rails - not drop-in compatible. | Choose SN65LVDS100DR only if migrating to LVDS infrastructure and redesigning termination network. |
Compared with MC100ELT20DG, SN65ELT20DR offers identical functionality at lower cost and broader availability, while SN65LVDS100DR provides higher speed but requires full interface redesign due to incompatible signaling and supply.
Availability
SN65ELT20DR is available at Aetrix Electronics and suitable for backplane clock distribution, high-speed data link interfaces, and telecom line card timing requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for SN65ELT20DR 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 decades of expertise in high-speed interface solutions.
The SN65ELT20DR belongs to TI's high-speed logic translator product line, engineered specifically for reliable, low-skew signal conversion between single-ended TTL and differential PECL domains in industrial and communications infrastructure.
FAQ
What is the recommended termination for SN65ELT20DR PECL outputs?
The SN65ELT20DR PECL outputs (Q and Q̅) must each be terminated with a 50-Ω resistor to VCC – 2 V. This configuration establishes the proper common-mode voltage (≈1.8 V) and differential swing (≈700–800 mVPP) required for PECL receiver compatibility. Using 50-Ω to ground or AC coupling without DC bias will result in invalid logic levels and signal integrity failure.
Does SN65ELT20DR support operation below 4.2 V?
No, SN65ELT20DR is not specified for operation below 4.2 V. The datasheet defines the absolute minimum supply voltage as 4.2 V under all operating conditions. Operation at 3.3 V or lower will cause undefined output behavior, increased propagation delay, and potential failure to meet PECL voltage thresholds. For 3.3-V systems, consider LVDS translators like SN65LVDS100DR instead.
Can SN65ELT20DR drive multiple PECL loads simultaneously?
SN65ELT20DR is designed to drive one standard PECL load (50-Ω to VCC – 2 V per output). Driving multiple loads in parallel violates the required termination and degrades signal integrity, causing reflections, reduced swing, and timing violations. For fanout, use dedicated PECL fanout buffers (e.g., SY100EL15) after SN65ELT20DR translation.
Is SN65ELT20DR pin-compatible with SN65ELT20D and SN65ELT20DGK?
Yes, SN65ELT20DR shares identical pinout and electrical specifications with SN65ELT20D (SOIC-8 tube) and SN65ELT20DGK (TSSOP-8). All three variants use the same die and functional design; only packaging (SOIC tape-and-reel vs tube vs TSSOP) and reel specifications differ. Layouts designed for SN65ELT20D are directly usable for SN65ELT20DR.
What is the meaning of "flow-through pinout" for SN65ELT20DR?
The flow-through pinout of SN65ELT20DR places the TTL input (D) on Pin 2 and complementary PECL outputs (Q on Pin 6, Q̅ on Pin 7) on the opposite side of the SOIC-8 package. This arrangement allows straight-line PCB routing - input trace enters left side, output traces exit right side - minimizing vias, crosstalk, and stub length in high-speed layouts.
SN65ELT20DR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 65ELT
- Package/Case:
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Translator Type:
- Mixed Signal
- Channel Type:
- Unidirectional
- Number of Circuits:
- 1
- Channels per Circuit:
- 1
- Voltage - VCCA:
- -
- Voltage - VCCB:
- -
- Input Signal:
- TTL
- Output Signal:
- PECL
- Output Type:
- Differential
- Data Rate:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Features:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC (0.154", 3.90mm Width)
SN65ELT20DR FAQ
1.How can I place an order for SN65ELT20DR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN65ELT20DR 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 SN65ELT20DR reliable?
The price and inventory of SN65ELT20DR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN65ELT20DR is usually 5 days.
3.What payment methods are accepted for SN65ELT20DR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN65ELT20DR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN65ELT20DR?
SN65ELT20DR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN65ELT20DR 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 SN65ELT20DR?
For technical support, including SN65ELT20DR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN65ELT20DR requirements.
6.How does Aetrix verify that SN65ELT20DR is sourced from the original manufacturer or authorized distributors?
All SN65ELT20DR 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 SN65ELT20DR meets industry standards.
7.What is the process for return or replacement of SN65ELT20DR?
All SN65ELT20DR units undergo pre-shipment inspection (PSI). If there is an issue with SN65ELT20DR, 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 SN65ELT20DR part is unused and in its original packaging.
Return procedure for SN65ELT20DR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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