TTI LTX-510 Electro-Optic Conversion Module
| Brand | TTI |
|---|---|
| Origin | USA |
| Model | LTX-510 |
| Input Voltage Range | 0–1 V or 0–5 V (selectable) |
| Input Impedance | 50 Ω or 1 MΩ (switchable) |
| Output Optical Power | 10 mW (−20 dBm) |
| Maximum Input Voltage | ±7 V DC |
| 3-dB Bandwidth | DC–60 MHz |
| Center Wavelength | 850 nm |
| Spectral Width (FWHM) | 100 nm |
| Input Connector | BNC Female |
| Output Connector | ST |
| Compatible Fiber | Multimode, 62.5/125 µm or 100/140 µm |
Overview
The TTI LTX-510 Electro-Optic Conversion Module is a precision analog signal isolator engineered for high-fidelity transmission of voltage signals over optical fiber in electrically hostile environments. It operates on the principle of direct intensity modulation: an input analog voltage drives a high-linearity 850 nm vertical-cavity surface-emitting laser (VCSEL), whose optical output power varies linearly with the applied voltage. This electro-optic transduction enables galvanic isolation—eliminating ground loops, common-mode voltage interference (>1 kV), and electromagnetic coupling—while preserving signal integrity from DC through 60 MHz. Designed specifically for integration into measurement chains where electrical isolation is non-negotiable, the LTX-510 serves as the transmit-stage counterpart to the TIA-525 series photoreceivers, forming a bidirectional, low-latency, fiber-based analog link.
Key Features
- DC–60 MHz analog bandwidth with <±0.5 dB gain flatness across full frequency range, verified per IEEE Std 1057 sinusoidal fitting methodology
- Selectable input voltage range: 0–1 V or 0–5 V full-scale, configurable via front-panel DIP switch
- Switchable input impedance: 50 Ω for RF-coupled sources; 1 MΩ for high-impedance sensor outputs (e.g., piezoelectric transducers, HV dividers)
- Optical output calibrated to −20 dBm (10 mW) at full-scale input, traceable to NIST-standard optical power meters
- Robust VCSEL source with center wavelength 850 nm ±5 nm and spectral FWHM ≤100 nm—optimized for coupling efficiency into standard multimode fiber
- BNC female input connector and ST-style output ferrule ensure mechanical stability and repeatable alignment in lab and industrial enclosures
- Operates from a single +15 V DC supply (±5%), with internal regulation and thermal compensation to maintain gain stability over 0–50 °C ambient
Sample Compatibility & Compliance
The LTX-510 is compatible with industry-standard 62.5/125 µm and 100/140 µm graded-index multimode fibers, supporting link distances up to 500 m without repeaters under typical lab conditions. Its isolation rating exceeds 3.75 kVRMS (1 min, per IEC 61000-4-5 surge test waveform), making it suitable for deployment adjacent to plasma confinement vessels, high-voltage switchgear, pulsed laser amplifier stacks, and RF induction heaters. The module complies with EN 61326-1 (EMC for laboratory equipment), UL 61010-1 (safety), and RoHS 2015/863/EU. When paired with a TIA-525 receiver and used in a validated configuration, the full link meets requirements for Class I, Division 2 hazardous location signaling per NEC Article 500.
Software & Data Management
The LTX-510 is a hardware-only analog transducer with no embedded firmware, microcontroller, or digital interface—ensuring deterministic latency ( 100 dB at 1 MHz)—are supplied with each unit and remain valid for 12 months under documented storage conditions.
Applications
- Plasma physics diagnostics: Isolating Langmuir probe bias voltages and floating potential signals in tokamak and stellarator experiments
- High-voltage power electronics: Transmitting gate-drive timing signals and bus voltage feedback across >10 kV potential gradients in modular multilevel converters (MMCs)
- Laser system monitoring: Relaying Q-switch trigger timing, cavity dump signals, and thermal sensor outputs from amplifier heads operating at >10 kW average power
- Pulsed power instrumentation: Capturing fast-rise (sub-ns) current monitor outputs from Rogowski coils and current transformers in Z-pinch facilities
- Industrial motor drive commissioning: Galvanically isolated acquisition of PWM-modulated phase voltages in 6.6 kV medium-voltage inverters
FAQ
What is the maximum common-mode voltage the LTX-510 can withstand between input ground and fiber shield?
The module provides 3.75 kVRMS isolation per IEC 61000-4-5; continuous common-mode voltage must not exceed 1.5 kVDC or 1.0 kVAC RMS for long-term reliability.
Can the LTX-510 be used with single-mode fiber?
No—it is optimized for multimode coupling. Attempting single-mode use results in >15 dB insertion loss and modal noise due to mismatched NA and core diameter.
Is temperature drift compensated in the gain path?
Yes. Internal thermistor feedback maintains gain variation within ±0.02 %/°C from 20–40 °C; full-spec performance is guaranteed from 0–50 °C.
Does the LTX-510 support differential input?
No. It accepts only single-ended voltage inputs. For differential signals, an external unity-gain difference amplifier (e.g., AD8476) with sufficient CMRR must precede the LTX-510.
What calibration documentation is provided?
Each unit ships with a factory calibration report listing measured gain, bandwidth (−3 dB point), output power vs. input voltage linearity (R² ≥ 0.99999), and isolation resistance at 500 VDC.
