STK672-442BN-E

No.A2249-17/28

2-2.[Overcurrent detection]

This hybrid IC is equipped with a function for detecting overcurrent that arises when the motor burns out or when there is

a short between the motor terminals.

Overcurrent detection occurs at 3.4A typ with the STK672-432BN-E, and 5.0A typ with the

STK672-440BN-E/442BN-E.

Overcurrent detection begins after an interval of no detection (a dead time of 1.25

s typ) during the

initial ringing part during PWM operations. The no detection interval is a period of time where

overcurrent is not detected even if the current exceeds IOH.

2-3. [Overheat detection]

Rather than directly detecting the temperature of the semiconductor device, overheat detection detects the temperature of

the aluminum substrate (144

C typ).

Within the allowed operating range recommended in the specification manual, if a heat sink attached for the purpose of

reducing the operating substrate temperature, Tc, comes loose, the semiconductor can operate without breaking.

However, we cannot guarantee operations without breaking in the case of operations other than those recommended,

such as operations at a current exceeding IOH max that occurs before overcurrent detection is activated.

Set motor

current, IOH

PWM period

No detection interval

(1.25

s typ)

1.25

s typ

MOSFET all OFF

IOHmax

Normal operation

Operation when motor pins are shorted

Current when motor terminals are shorted

Overcurrent detection