AAT1110-T2 AAT [Advanced Analog Technology, Inc.], AAT1110-T2 Datasheet - Page 5

• Manufacturer Part Number: AAT1110-T2
• Description: ONE-CHANNEL STEP-DOWN PWM CONTROLLER
• Manufacturer: AAT [Advanced Analog Technology, Inc.]

How to Set the Time Constant for Soft-Start and Short Circuit Protection
1. Soft-Start
At power on, the AAT1110 operates in soft-start mode. The capacitor
charging at a constant current. In the soft-start mode, the voltage at SCP pin (
comparator, so that the ON duty of the OUT pin is controlled by the
operation, the voltage at the SCP pin stays low; the input from soft-start circuit to the PWM comparator
stays high, and enters the short circuit protection waiting state.
2. Short Circuit Protection
If the switching regulator output suddenly drops due to loading effect, the error amplifier output will be
fixed at
approximately 1.26V, the output pin will set low and SCP pin will remain low.
Once the protection circuit starts operating, the circuit can be recovered by setting the power supply.
Soft-Start Time
Short Circuit Detection Time
t
s
t
(sec)
scp
V
OM
(sec)
+
~
. 0
and capacitor
~
84
. 0
Advanced Analog Technology, Inc.
×
84
C
×
SCP
C
SCP
–
(
–
µ
) F
(
Advanced Analog Technology, Inc
C
µ
台灣類比科技股份有限公司
) F
SCP
will start charging. When the voltage at the SCP pin reaches
Page 5 of 17
V
SCP
C
SCP
. At completion of the soft-start
V
connected to SCP pin starts
.
–
–
SCP
) is input to the PWM
AAT1110
V 1.0