LV8773

No.A1961-10/26

(7) Output short-circuit protection function

This IC incorporates an output short-circuit protection circuit that, when the output has been shorted by an event such

as shorting to power or shorting to ground, sets the output to the standby mode and turns on the warning output in

order to prevent the IC from being damaged. In the channels 1 and 2 operate independently. (Even if the output of

channel 1 has been short-circuited, channel 2 will operate normally.)

(7-1) Output short-circuit protection operation changeover function

Changeover to the output short-circuit protection of IC is made by the setting of EMM pin.

EMM

State

Low or Open

Latch method

High

Auto reset method

(7-2) Latch type

In the latch mode, when the output current exceeds the detection current level, the output is turned OFF, and this state

is held.

The detection of the output short-circuited state by the IC causes the output short-circuit protection circuit to be

activated.

When the short-circuited state continues for the period of time set using the internal timer (approximately 2

μs), the

output in which the short-circuiting has been detected is first set to OFF. After this, the output is set to ON again as

soon as the timer latch time (Tcem) described later has been exceeded, and if the short-circuited state is still detected,

all the outputs of the channel concerned are switched to the standby mode, and this state is held.

This state is released by setting ST to low.

Short-circuit

Short-

circuit

Short-circuit

detection state

CEM voltage

H-bridge

output state

Internal counter

1st counter

start

1st counter

stop

1st counter

start

1st counter

end

2nd counter

start

2nd counter

end

Release

Threshold voltage

Output OFF

Output ON

Output ON

Standby state