IR3623MPBF_1 IRF [International Rectifier], IR3623MPBF_1 Datasheet - Page 14

• Manufacturer Part Number: IR3623MPBF_1
• Description: HIGH FREQUENCY 2-PHASE, SINGLE OR DUAL OUTPUT SYNCHRONOUS STEP DOWN CONTROLLER WITH OUTPUT TRACKING AND SEQUENCING
• Manufacturer: IRF [International Rectifier]

Fault Protection
The IR3623 monitors the output voltage for over voltage protection and power good indication. It senses
the R
conditions. Figure below shows the IC’s operating waveforms under different fault conditions.
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OV_Output
Ph_Enable
t
from tri-state. Soft start sequence starts.
t
t
t
t
t
t
t
generated. The PWM output is kept in tri-state until Ph-Enable goes high.
0
1
1
4
5
6
8
9
– t
:
– t
– t
– t
–t
– t
–t
OVP event. Ph_Enable is kept high and PWM is pulled low. OVP-Output flags high to indicate OV event.
PGood
6
7
10
PWM
2
3
5
1
:
:
ds(on)
:
:
:
:
:
POR
OC is removed, recovery sequence, fresh SS.
Ph_Enable goes high and PWM switches high from tri-state. Output voltage reaches the set voltage.
Iout
Vo
Output voltage ramps up and reaches the set voltage.
OC event, SS ramps down, Ph-Enable pulls low and PWM tri-states. IC in Hiccup mode.
Power Good signal flags high.
Vcc, 5V_sns and Enable signals passed their respective UVLO threshold. Ph_Enable goes high and PWM switches high
Manually recycled the Vcc after latched OVP. PreBias start up. The Ph_Enable goes high after first internal PWM pulse is
SS
Tri_State
of low side MOSFET for over current protection. It also protects the output for prebias
90%Vfb
1.8V
1.0V
3V
t
0
t
1
t
2
t
Set Voltage
3
t
4
OCP Threshold
Fig. 12: Fault Conditions
t
5
t
6
t
7
t
8
t
9
IR3623MPbF
t
10
Pre_Bias Voltage
14