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7.7. Over-temperature detecion circuit
(1) This IC builds in the over-temperature detection circuit. When the temperature becomes more than
TSD, the motor drive output, OUT1/2 changes to High-Z state, and the IC is protected.
(2) "L" is output from DIAG pin on this time.
(3) Moreover, even if temperature falls less than TSD-TSDhys by a functional operation of the
over-temperature detection, the IC does not return automatically, and the output state holds latching
High-Z.
(4) DIAG output pin also latches the abnormal state.
(5) "L" output latch state of DIAG pin is cleared with a rising edge of the EN pin or a falling edge of the
ENB pin.
(6) For the chattering prevention at the time of over-temperature detection, a filter circuit is built-in.
Detection
=170℃↑
ENB pin
Motor
drive
output
DIAG
output
Figure 7.7 Timing chart of over-temperature detection operation
Note: When detection signals of the over-temperature detection circuit become less than the VBAT
undervoltage, the state before the VBAT detection is held.
The detection signals of over-temperature detection circuit are made into undetected state forcibly
during an initial diagnosis and a re-start.
Note: PWM input is not available at the time of TSD generation.
Note: Some of timing charts in this document may be omitted or simplified for explanatory purposes.
Note: The guarantee storage temperature range of the absolute maximum ratings of this product is
maximum 150°C. The storage and use exceeding this temperature are not guaranteed a normal
operation of the IC. It also may occur smoke and fire. Do not store and use exceeding this
temperature in any cases.
Moreover although this IC builds in the over-temperature detection function, this function is not a
function of which the temperature of this IC is suppressed less than thermal shutdown
temperature.
This function is out of operation guarantee ranges and provided as an auxiliary only.
(For this function, the TEST is not performed with actual difference in temperature individually.
Only detection circuit operation is confirmed tentatively by the TEST function.)
H
EN pin
L
H
L
H
Outputs
High-z
L
H
L
Over-temperature
detection
(6)
(1)
(3)
Outputs
High-z
(2)
(4)
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TB9051FTG
(5)
Ver.1.1 2019-03-14
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