My Inquiry
My Account
Texas Instruments SN65ELT20DGKR
- Part No.:
- SN65ELT20DGKR
- Manufacturer:
- Texas Instruments
- Category:
- Translators, Level Shifters
- Package:
- Datasheet:
-
SN65ELT20DGKR.pdf
- Description:
- IC TRANSLATOR UNIDIR 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,980
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN65ELT20DGKR 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 with 3915–4120 mV VOH and 3170–3380 mV VOL (terminated to VCC – 2 V), and supports up to 430 MHz switching frequency.
For engineers reviewing the SN65ELT20DGKR datasheet, SN65ELT20DGKR pinout, SN65ELT20DGKR application, or SN65ELT20DGKR 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 SN65ELT20DGKR implements a single-channel unidirectional translation path: one TTL input drives complementary PECL outputs (Q and Q̅) with matched internal delays. Its output stage is designed for 50-Ω termination to VCC – 2 V, ensuring precise differential swing and minimal skew (<0.5 ns typical between Q/Q̅ edges).
It contains no internal biasing for floating inputs - the TTL input must be actively driven or externally terminated - and incorporates built-in temperature compensation to stabilize output voltage levels across –40°C to 85°C ambient operation without external calibration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.2 V to 5.7 V - Enables robust operation across industrial-grade 5-V rail tolerances, including noisy or aging power supplies. |
| Propagation Delay | ≤1.25 ns (tPLH/tPHL) - Guarantees sub-nanosecond timing margin for 430-MHz clock distribution and high-speed serial data paths. |
| Output Swing | VOH = 3915–4120 mV, VOL = 3170–3380 mV (50 Ω to VCC – 2 V) - Delivers standard PECL-compliant differential amplitude of ~750 mVPP at 5 V supply. |
| Max Switching Frequency | 430 MHz - Supports PCIe Gen1/Gen2 reference clocks, SONET/SDH framing, and parallel bus timing in telecom and computing backplanes. |
| Input Thresholds | VIH = 2.0 V min, VIL = 0.8 V max - Compatible with standard 5-V TTL logic families without level-shifting circuitry. |
| Power Supply Current | 9.6–10.7 mA (–40°C to 85°C) - Enables predictable thermal budgeting in dense PCB layouts with multiple translators. |
| Random Jitter (RMS) | 0.5 ps - Meets low-jitter requirements for jitter-sensitive clock recovery and SERDES applications. |
Pinout & Package
VSSOP-8 (DGK) package: 3.0 mm × 3.0 mm body, 1.1 mm max height, 0.65 mm lead pitch, exposed pad optional (not electrically connected per TI documentation), RoHS-compliant NiPdAu lead finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (D) | TTL input | Single-ended 5-V TTL signal source; requires active drive or pull-up/down - floating state yields indeterminate outputs. |
| 2 (Q) | PECL output (true) | Differential true output, terminated to VCC – 2 V via 50 Ω; provides standard ECL-compatible logic polarity. |
| 3 (Q̅) | PECL output (complement) | Complementary differential output; matched delay and amplitude to Pin 2 ensures <0.5 ns skew for clean differential signaling. |
| 4 (GND) | Ground reference | Primary return path for TTL input and internal biasing; must be low-inductance connection to minimize noise coupling. |
| 5 (VCC) | Positive supply | 5-V supply input; decoupling capacitor (0.1 µF ceramic + 4.7 µF tantalum) required within 5 mm for stable PECL output integrity. |
| 6 (NC) | No-connect | Internally unused; must remain unconnected - not for grounding or routing. |
| 7 (NC) | No-connect | Internally unused; must remain unconnected - not for grounding or routing. |
| 8 (NC) | No-connect | Internally unused; must remain unconnected - not for grounding or routing. |
Key Features
| Feature | Design Value |
|---|---|
| Flow-through pinout | Pins D (1), Q (2), Q̅ (3), GND (4), VCC (5) align linearly - enables straight PCB trace routing with minimal layer transitions and stub reduction. |
| Built-in temperature compensation | Maintains consistent VOH/VOL over –40°C to 85°C without external components - eliminates need for calibration or trimming in field-deployed systems. |
| Low output skew | <0.5 ns between Q and Q̅ edges - preserves differential integrity for clock distribution and high-speed data eye opening. |
| Drop-in compatibility | Pin- and function-compatible with MC10ELT20/MC100ELT20 - allows legacy design reuse without layout revision when upgrading to TI's enhanced reliability process. |
| ESD protection | >4 kV HBM, 2 kV CDM - exceeds JEDEC JS-001 Class 2 requirements, reducing handling sensitivity during SMT assembly and board test. |
Applications
| Backplane Clock Distribution | SONET/SDH Frame Timing |
|---|---|
|
Use Scenario: Distributing a centralized 155.52 MHz or 622.08 MHz reference clock across a multi-slot telecom chassis via differential traces. IC Role / Device Role / Timing Role: Translates TTL-formatted clock from system controller into robust differential PECL signals for low-noise, long-distance transmission. Use Value: 1.25-ns delay matching and 0.5-ps jitter preserve clock edge integrity, enabling reliable PLL lock and minimizing bit error rates in OC-3/OC-12 links. |
Use Scenario: Converting FPGA-generated TTL control/status signals to PECL levels for inter-board communication in line-card synchronization circuits. IC Role / Device Role / Timing Role: Provides level-shifted, low-skew differential outputs compatible with PECL receivers on adjacent cards. Use Value: Flow-through pinout simplifies routing across card-edge connectors; 430-MHz bandwidth supports future upgrades to OC-48 timing protocols. |
| High-Speed Data Bus Interface | Test Equipment Signal Conditioning |
|
Use Scenario: Driving parallel 8-bit data lanes from a microcontroller to a high-speed ADC/DAC module requiring PECL-level inputs. IC Role / Device Role / Timing Role: Unidirectional TTL-to-PECL translator for each data line, ensuring simultaneous edge alignment across all bits. Use Value: Matched tPLH/tPHL across channels minimizes inter-symbol skew, preserving setup/hold margins at 100+ MSPS sampling rates. |
Use Scenario: Integrating into automated test equipment (ATE) channel cards to convert pattern generator outputs to PECL for DUT stimulus. IC Role / Device Role / Timing Role: Precision timing translator enabling repeatable, low-jitter stimulus generation for jitter tolerance testing. Use Value: 0.5-ps RMS jitter meets IEEE 1149.6 AC-JTAG compliance thresholds; VSSOP-8 footprint saves space in densely packed ATE modules. |
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 and DC/AC specs; uses older bipolar process with higher ICC (12–15 mA) and no built-in temperature compensation. | Limited lifetime availability; lacks TI's enhanced ESD rating (>4 kV HBM vs. 2 kV) and modern thermal resistance (θJA = 120°C/W vs. 119°C/W). | Acceptable for legacy repair or cost-sensitive non-automotive designs where long-term supply is secured. |
| SN65LVDS100DGK | LVDS output (not PECL); 3.3-V supply only; 1.5-Gbps data rate but incompatible termination (100 Ω diff vs. 50 Ω to VCC–2 V). | Requires redesign of receiver termination and supply rails; unsuitable for PECL-based infrastructure already deployed. | Only viable if migrating entire system to LVDS signaling and 3.3-V architecture - not a drop-in replacement. |
Compared with MC100ELT20DG and SN65LVDS100DGK, the SN65ELT20DGKR offers superior thermal stability, lower jitter, and guaranteed long-term sourcing - making it the preferred choice for new designs targeting telecom backplanes and test instrumentation where PECL compatibility and timing fidelity are mandatory.
Availability
SN65ELT20DGKR is available at Aetrix Electronics and suitable for backplane clock distribution, SONET/SDH timing, high-speed data bus interfacing, and automated test equipment requiring stable component supply, full traceability, and extended lifecycle support.
Supply support for SN65ELT20DGKR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and industrial-grade performance.
The SN65ELT20DGKR belongs to TI's high-speed interface translator product line, engineered specifically for robust, low-skew signal conversion in telecom infrastructure, test equipment, and computing backplanes operating under wide temperature and supply-voltage ranges.
FAQ
What is the recommended termination for SN65ELT20DGKR PECL outputs?
The SN65ELT20DGKR PECL outputs (Q and Q̅) must be terminated to VCC – 2 V using two 50-Ω resistors - one from Q to VCC – 2 V, and one from Q̅ to VCC – 2 V. This configuration establishes the standard PECL common-mode voltage and delivers the specified 750-mVPP differential swing. Using AC-coupled or unterminated configurations will result in undefined output levels and degraded jitter performance.
Does SN65ELT20DGKR support operation at 3.3 V?
No, the SN65ELT20DGKR is specified exclusively for 4.2 V to 5.7 V operation. It does not function reliably below 4.2 V, and applying 3.3 V will result in invalid PECL output voltages, excessive propagation delay, and potential functional failure. For 3.3-V systems, TI recommends the SN65LVDS100 series - though those deliver LVDS, not PECL, outputs.
Can SN65ELT20DGKR inputs be left floating?
No - the SN65ELT20DGKR TTL input (Pin 1) must never be left floating. An undriven input causes indeterminate output states and may increase power consumption or generate spurious edges. TI specifies that the input must be actively driven or externally pulled to a valid VIH (≥2.0 V) or VIL (≤0.8 V) level using appropriate series resistance and termination.
Is SN65ELT20DGKR pin-compatible with MC10ELT20 in VSSOP-8?
Yes - the SN65ELT20DGKR shares identical VSSOP-8 (DGK) pinout, electrical specifications, and mechanical dimensions with the MC10ELT20DG variant. TI explicitly documents "drop-in compatibility" in the datasheet, confirming identical pin functions, timing, and layout requirements - enabling direct substitution without PCB modification.
What is the thermal resistance (θJA) of SN65ELT20DGKR in its VSSOP-8 package?
The SN65ELT20DGKR in VSSOP-8 (DGK) package has a junction-to-ambient thermal resistance (θJA) of 213°C/W under low-thermal-conductivity PCB conditions and 189°C/W under high-thermal-conductivity conditions, per TI's POWER DISSIPATION RATINGS table. These values assume standard JEDEC test board conditions with transverse airflow >500 lfpm.
SN65ELT20DGKR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 65ELT
- Package/Case:
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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-TSSOP, 8-MSOP (0.118", 3.00mm Width)
SN65ELT20DGKR FAQ
1.How can I place an order for SN65ELT20DGKR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN65ELT20DGKR 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 SN65ELT20DGKR reliable?
The price and inventory of SN65ELT20DGKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN65ELT20DGKR is usually 5 days.
3.What payment methods are accepted for SN65ELT20DGKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN65ELT20DGKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN65ELT20DGKR?
SN65ELT20DGKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN65ELT20DGKR 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 SN65ELT20DGKR?
For technical support, including SN65ELT20DGKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN65ELT20DGKR requirements.
6.How does Aetrix verify that SN65ELT20DGKR is sourced from the original manufacturer or authorized distributors?
All SN65ELT20DGKR 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 SN65ELT20DGKR meets industry standards.
7.What is the process for return or replacement of SN65ELT20DGKR?
All SN65ELT20DGKR units undergo pre-shipment inspection (PSI). If there is an issue with SN65ELT20DGKR, 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 SN65ELT20DGKR part is unused and in its original packaging.
Return procedure for SN65ELT20DGKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN65ELT20DGKR Tags
-
74LVC1T45GW,125
Nexperia USA Inc.
-
74LVCH2T45DC,125
Nexperia USA Inc.
-
SN74LVC1T45DBVR
Texas Instruments
-
SN74LVC1T45DRLR
Texas Instruments
-
SN74LVC1T45DPKR
Texas Instruments
-
SN74LVC2T45DCTR
Texas Instruments
-
74LVC2T45GT,115
Nexperia USA Inc.
-
SN74LVC1T45YZPR
Texas Instruments
-
LSF0102DCUR
Texas Instruments
-
SN74LVC1T45DCKR
Texas Instruments
-
TXS0102DCTR
Texas Instruments
-
FXLP34P5X
onsemi
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…
