tb6641fg TOSHIBA Semiconductor CORPORATION, tb6641fg Datasheet - Page 10

• Manufacturer Part Number: tb6641fg
• Description: Full-bridge Dc Motor Driver Ic
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Predefined VISD value 7A (typ.)
6.
ISD operation
Overcurrent Shutdown Circuit
The TB6641FG incorporates overcurrent shutdown (ISD) circuits monitoring the current that flows through
each of all the four output power transistors.
The detection current threshold is 7A (typ.). If the overcurrent flowing through any one of the ISD circuit
flows beyond the detected time threshold, all the outputs are turned off (Hi-Z).
The detection time threshold is controllable through the external resistor of the TISD pin.
Driving both the IN1 pin and IN2 pin Low allows a release of the shutdown operations; the TB6641FG
resumes the normal operation.

Note: The ISD circuit is activated if the absolute maximum current rating is violated. Note that the circuit is
Detection time threshold of the external resistor, R1, of the TISD pin
10 k: 1.6 s (typ.)
20 k: 2.8 s (typ.)
100 k: 12.4 s (typ.)
Internal ISD signal
provided as an auxiliary only and does not necessarily provide the IC with a perfect protection from
damages due to overcurrent caused by power fault, ground fault, load-short and the like.
Output current
ALERT output
OUT1, OUT2
(4.5A to 10A)
IN1, IN2
H
H
H
L
L
L
0
T: Predefined TISD value
Normal operation
IC
(ISD)
TISD pin
R1
10
OFF (Hi-Z)
Normal operation
More than 1 s (typ.)
TB6641FG
2011-06-21