A3950SEU-T Allegro MicroSystems, Inc., A3950SEU-T Datasheet - Page 8

• Manufacturer Part Number: A3950SEU-T
• Description: A3950 4X4 QFN
• Manufacturer: Allegro MicroSystems, Inc.

A3950
NFAULT low, but does not disable the operation of the chip. If
the die temperature increases further, to approximately 175°C, the
full-bridge outputs will be disabled until the internal temperature
falls below a hysteresis of 15°C.
Overcurrent Protection. Referring to the figures below, the
voltage on the output pins relative to supply are monitored to
ensure that the motor lead is not shorted to supply or ground.
Shorted load condition, output current waveform is shown along with the NFAULT output.
NFAULT
Shorted load condition illustrating repetitive cycles with a 1.2 ms delay.
NFAULT
I
I
SHORT
SHORT
T
OCP
= 1.2 ms
DMOS Full-Bridge Motor Driver
Fault asserted
If a short is detected, the full-bridge outputs are turned off, flag
NFAULT is driven low, and a 1.2 ms fault timer is started.
After this 1.2 ms period, t
to follow the input commands and another turn-on is attempted.
If there is still a fault condition, the cycle repeats. If, after t
expires, it is determined that the short condition is not present, the
NFAULT pin is released and normal operation resumes.
Fault asserted
200 μs / div.
2 μs / div.
2 A / div.
2 A / div.
OCP
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
, the device will then be allowed
OCP
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