
TPD4105K
2007-05-10
12
Description of Protection Function
(1)
Over-current protection
This product incorporates the over-current protection circuit to protect itself against over-current at
startup or when a motor is locked. This protection function detects voltage generated in the current
detection resistor connected to the RS pin. When this voltage exceeds VR (= 0.5 V typ.), the IGBT
output, which is on, temporarily shuts down after a dead time, preventing any additional current
from flowing to this product. The next all “L” signal releases the shutdown state.
(2)
Under-voltage protection
This product incorporates under voltage protection circuits to prevent the IGBT from operating in
unsaturated mode when the VCC voltage or the VBS voltage drops.
When the VCC power supply falls to this product internal setting VCCUVD (=11 V typ.), all IGBT
outputs shut down regardless of the input. This protection function has hysteresis. When the VCC
power supply reaches 0.5 V higher than the shutdown voltage (VCCUVR (=11.5 V typ.)), this product
is automatically restored and the IGBT is turned on again by the input.
When the VBS supply voltage drops VBSUVD (=9 V typ.), the high-side IGBT output shuts down.
When the VBS supply voltage reaches 0.5 V higher than the shutdown voltage (VBSUVR (=9.5 V
typ.)), the IGBT is turned on again by the input signal.
(3)
Thermal shutdown
This product incorporates a thermal shutdown circuit to protect itself against excessive rise in
temperature.When the temperature of this chip rises to the internal setting TSD due to external
causes or internal heat generation all IGBT outputs shut down regardless of the input. This
protection function has hysteresis
ΔTSD (= 50 °C typ.). When the chip temperature falls to TSD
ΔTSD, the chip is automatically restored and the IGBT is turned on again by the input.
Because the chip contains just one temperature-detection location, when the chip heats up due to the
IGBT, for example, the differences in distance between the detection location and the IGBT (the
source of the heat) can cause differences in the time taken for shutdown to occur. Therefore, the
temperature of the chip may rise higher than the initial thermal shutdown temperature.
Safe Operating Area
Note 1: The above safe operating areas are at Tj
= 135°C (Figure 1).
Note 2: The above safe operating areas include the over-current protection operation area.
2.7
Peak
winding
current
(A)
Power supply voltage VBB (V)
Figure 1 SOA at Tj
= 135°C
0
450
0
400
3