TB6561FG

2007-5-11

7

3.

Overcurrent Protection Circuit (ISD)

The IC incorporates an overcurrent protection circuit to detect voltage that flows through the output

transistors. The overcurrent threshold is 2.5 A (typ.).

Currents that flow through the output transistors are monitored individually. If overcurrent is detected in

at least one of the transistors, all transistors are turned off.

The IC incorporates a timer to count 50

μs (typ.) for which the transistors are off. After 50 μs, they are

turned on automatically. If an overcurrent occurs again, the same operation is repeated. To prevent false

detection due to glitch, the circuit turns off the transistors only when current that exceeds the overcurrent

threshold flows for 10

μs or longer.

The over-current threshold is a target spec. It varies in a range from approximately 1.5 A to 3.5 A.

50

μs

(typ.)

0

10

μs

(typ.)

Not detected

50

μs

(typ.)

10

μs

(typ.)

Output current