ir3831 International Rectifier Corp., ir3831 Datasheet - Page 14

• Manufacturer Part Number: ir3831
• Description: Synchronous Buck Regulator For Ddr Applications
• Manufacturer: International Rectifier Corp.

Thermal Shutdown
Temperature sensing is provided inside IR3831.
The trip threshold is typically set to 140
trip threshold is exceeded, thermal shutdown
turns off both MOSFETs and discharges the soft
start capacitor.
Automatic restart is initiated when the sensed
temperature drops within the operating range.
There is a 20
shutdown threshold.
02/20/09
o
C hysteresis in the thermal
Fig.8a IR3831 Non-Tracking Operation
Fig.8b IR3831 Tracking Operation
TIMING DIAGRAM OF PGOOD FUNCTION
o
C. When
Power Good Output
The IC continually monitors the output voltage via
Feedback (Fb pin). The feedback voltage is
compared to a fixed voltage. As soon as the Fb
voltage reaches 0.515 V, the Power Good signal
flags. This pin is open drain and it needs to be
externally pulled high. High state indicates that
output is in regulation. Fig 8. shows the timing
diagram for the PGood function.
IR3831MPbF
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