tlp (transmission line pulse)
**TLP** (Transmission Line Pulse) is a **characterization technique for ESD protection devices** — generating precise, rectangular high-current pulses by discharging a charged transmission line, allowing measurement of the device's I-V characteristics under ESD-like conditions.
**What Is TLP?**
- **Principle**: A charged coaxial cable (transmission line) is switched into the DUT. The pulse width and amplitude are set by cable length and charge voltage.
- **Pulse Width**: Typically 100 ns (correlates to HBM time domain).
- **Output**: A quasi-static I-V curve at high current levels (0.1 - 10+ A).
- **Key Parameters**: Trigger voltage ($V_{t1}$), holding voltage ($V_h$), on-resistance ($R_{on}$), failure current ($I_{t2}$).
**Why It Matters**
- **ESD Design**: Engineers use TLP I-V curves to design and optimize ESD clamps — "What voltage does it clamp to? How much current can it handle?"
- **Quantitative**: Unlike HBM pass/fail, TLP provides continuous data for modeling.
- **Standard Tool**: Every ESD design team uses TLP testers (Barth, ESDEMC, Thermo Fisher).
**TLP** is **the oscilloscope for ESD clamps** — producing precise electrical portraits of protection devices under extreme current conditions.