RF Power Lifetime Calculator
Functionality
The RF Power Lifetime Calculator has been designed to assist our customers in estimating the LDMOS device reliability in years. The returned results are represented by MTF (Median-Time-To-Failure, the time that 50% of the population has failed) as a function of Junction Temperature (TJ) of the device, assuming electromigration as the wear-out failure mechanism. For two-stage MMICs the lifetime is determined by (and therefore only calculated for) the second/final stage. The tool covers four generations of RF power transistors (Gen6, Gen7, Gen8 and Gen9), available in the current product portfolio of Ampleon.
For GaN , the returned results are represented by MTF (Median-Time-To-Failure, the time that 50% of the population has failed) as a function of Surface Temperature (Ts) of the device, assuming Schottky and Ohmic degradation as the wear-out failure mechanisms specific for GaN HEMT devices.
About the Tool
This MTF tool performs calculations based on the user’s inputs. Default values are given per transistor as defined in product datasheets. In order to guarantee the validity of results, user’s inputs are also constrained by a set of limits.
Features
- The Input panel allows the user to select the desired transistor, drain voltage, drain current, input and output power.
- Selection of symmetrical and asymmetrical loads to estimate MTF either per device or per section is applicable to push-pull devices. Selection of different thermal conditions, pulse duration (tp) and duty cycle (δ), is applicable to pulsed devices.
- After selecting the product, default values appear in the input fields. These fields can be modified by the user, but all of them are constrained by a set of “soft” and “hard” limits.
- To obtain meaningful results for MTF and TJ, input values are restricted and classified as “soft” and “hard”, based on test and physical limits of the device. In case the input is not within a “soft” limit, a warning message will be produced in the Quick Help panel to recommend typical operational value(s) for the product. Should the user exceed a “hard” limit, no reliable estimations will be derived within the boundaries of the model since the device may perform beyond its physical capabilities, which are not supported by the test data.
- Drain Efficiency (ηD) and Power-added Efficiency (ηPAE) are used to perform an additional sanity check of the input(s).
- In the MTF panel the returned results for MTF, TJ, ηD and ηPAE are shown
Calculation procedure
The results are produced in the MTF panel, and either based on default value(s) or the value(s) introduced by the user in the field(s) of the Input panel.