TPD4144AK

2012-02-15

12

Description of Protection Function

(1)

Under voltage protection

This product incorporates under voltage protection circuits to prevent the IGBT from operating in

reversed.

the IGBT is turned on again by the input signal.

(2)

Thermal shutdown

This product incorporates a thermal shutdown circuit to protect itself against the abnormal state when

its temperature rises excessively.

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 from the detection location in the IGBT (the source of the

heat) cause differences in the time taken for shutdown to occur. Therefore, the temperature of the chip

may rise higher than the thermal shutdown temperature when the circuit started to operate.

(3)

SD pin

SD pin is the input signal pin to shut down the internal output IGBT. Output of all IGBT is shut down

after delay times (2 μs typ.) when "L" signal is input to the SD pin from external circuit (MCU etc.). It is

possible to shut down IC when overcurrent and others is detected by external circuit. Shut down state is

released by all of IC input signal "L". At open state of SD pin, shut down function can not operate.

Timing Chart of Under voltage protection and SD Function

Note: The above timing chart is considering the delay time.

Safe Operating Area

Note 1: The above safe operating areas are Tj

= 135 °C (Figure 1).

1.9

Figure 1 SOA at Tj

= 135 °C

0

450

0

400

2

SD

LIN

HO

HIN

LO

DIAG