lv8735v ON Semiconductor, lv8735v Datasheet - Page 21

• Manufacturer Part Number: lv8735v
• Description: Bi-cmos Lsi Pwm Constant-current Control Stepping Motor Driver
• Manufacturer: ON Semiconductor

Output short-circuit protection function
(1) Output short-circuit protection operation changeover function
(2) Latch type
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 stepping motor driver (STM) mode (DM = Low), this function
sets the output to the standby mode for both channels by detecting the short-circuiting in one of the channels. In the
DC motor driver mode (DM = High), channels 1 and 2 operate independently. (Even if the output of channel 1 has
been short-circuited, channel 2 will operate normally.)
Changeover to the output short-circuit protection of IC is made by the setting of EMM pin.
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 2μs), 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.
Internal counter
detection state
CEM voltage
output state
Short-circuit
H-bridge
Low or Open
EMM
1st counter
High
start
Short-
circuit
1st counter
stop
Release
Auto reset method
Output ON
1st counter
Latch method
start
State
Short-circuit
LV8735V
1st counter
end
Output OFF
Threshold voltage
2nd counter
start
Output ON
2nd counter
Standby state
end
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