6
Temperature monitoring
The SLLIMM 2nd series family integrates a temperature sensor (VTSO) on the low side gate driver and an NTC
thermistor placed close to the power stage.
They can be selected via SW3.
The board is designed to use both of them to monitor the internal IPM temperature through the MCU.
6.1
Thermal sensor (VTSO)
A voltage proportional to the temperature is available on the TSO pin (17) and easily measurable on the TP20 test
pin.
To improve noise immunity, a 1 nF (C16) capacitor filter is placed on this pin.
The thermal sensor does not need any pull down resistors.
The following graph shows typical voltage variation as a function of temperature.
Figure 15.
Thermal sensor voltage vs temperature
IGBT110820161234TSO
2.8
2.2
1.6
1.0
0.4
0
25
50
75
100
V
TSO
(V)
T (°C)
Min
Max
Typ
6.2
NTC Thermistor
The embedded thermistor (85 kΩ at 25 °C) in the IPM is connected between pins T1 and T2 (26, 25).
A12 kΩ pull down resistor (R10) ensures that the voltage variation on the NTC as a function of temperature is
almost linear. This voltage is easily monitored on TP1 test pin.
The figure below shows the typical voltage on T2 as function of temperature.
UM2702
Temperature monitoring
UM2702
-
Rev 1
page 17/34