BD64550EFV
Technical Note
●Protection function
○Protection circuit function
Overall
DC motor drive circuit
Switching regulator circuit
Series regulator circuit
Overheating protection
Overcurrent protection
Overcurrent protection, output overvoltage protection, output low voltage protection
None
○Operation at protection circuit operation
①Overheating protection・・・All functions are shutout along with junction temperature rise
Thermal shutdown temperature
175℃(typ.)
Switching regulator
At protection operation
OFF
Series regulator
OFF
DC motor
OFF
RESET
L
Re-start
Again power-on
②Overcurrent protection (Switching regulator)
Set current
ISWOC
2.6(A)
Operating
Switching regulator
OFF
Mask time
0.5µsec(※)
Series regulator
OFF
State after operation
All function shutout
DC motor
OFF
RESET
L
Re-start
Again power-on
③Overcurrent protection (DC motor)
Set current
IDCOC
3.8(A)
Operating
Switching regulator
ON
Mask time
1.5µsec
Series regulator
ON
State after operation
Shown below
DC motor RESET
OFF
L_PULSE
Re-start
Serial re-input
Motor current
RESET signal
IDCOC setting value
L
Serial data
Data default
1.5μsec 40msec
Fig.26 Timing Chart of Motor Overcurrent Protection
(※) If the output pulse of switching regulator is 0.5µs or below, the overcurrent function does not operate even at the time of overcurrent outflow.
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11/16
2010.06 - Rev.A