Appendix I: Summary of major characteristics of T3Ster

Measurement method: Measurement is done "on-the-fly", i.e. real-time measurement of the voltage drop across the sensor device at maximal sampling rate of 1 MHz. The voltage measurement takes place with 12 bit resolution. The measured voltage is converted to temperature change by the sensitivity parameters specified individually for each measurement channel. Measurement on each channel takes place simultaneously, resulting in real, synchronized multi-channel transient measurements.

Device structures:

• MOS transistor,
• bipolar transistor,
• diode (including substrate diodes of operable devices such as microprocessors),
• dedicated test chip with a resistor as heater & with a diode as temperature sensor
• thermocouples (J or K type) and IR sensors connected through thermocouple pre-amplifier)

Maximal power to switch:

• U_CB=10 V, I_E=2 A => 20 W
• U_diode@1 V, I=2 A => ~2 W (with booster: up to 20 W)
• U_max=50 V, I_max=2 A => 100 W (with booster: up to 1000 W)

Temperature measurement:

With diode:

Voltage ranges: 400mV / 200mV / 100mV / 50mV

The 100 mV range corresponds to about 50 °C range of the junction temperature rise

Resolution: 12 bit

In the100 mV range it results in LSB=25 µV, corresponding to ~10 m°C

Noise: ± 1 bit (prior to software filtering)

With thermocouple (using the T3Ster thermocouple pre-amplifier):

LSB corresponds to 25 m°C

Figure of merit (max. switched power / temperature resolution):

~ 10000 W/°C (with diode, without booster)

Number of measuring channels:

In the basic model there is one channel, further measuring units (1 channel/unit) can be ordered. Eight measuring units can be installed. On the parallel channels measurement and data acquisition takes place simultaneously.

Device calibration, measurement method, sampling rate:

Smart device calibration: K-factor identified at operating current levels. This way heating curve measurement takes place in real-time, "on the fly", with a quasi-logarithmic variable sampling rate. This rate is controlled by the measurement software. The hardware supports individual programming of sampling intervals between 1µs and 8s. Typically 200-300 data points are collected in an octave.