B3800 Bay Linear, B3800 Datasheet - Page 9

• Manufacturer Part Number: B3800
• Description: Step up Dc-to-dc Converter
• Manufacturer: Bay Linear

Soft Start
At power on, the capacitor CPE connected to the SCP pin
starts charging. The PWM comparator compares the soft start
setting voltage as a proportion of the voltage at the SCP pin
with the sawtooth waveform. The comparison controls the ON
duty of the OUT pin, causing the soft start operation. On
completion of soft start operation, the voltage at the SCP pin
stays low, the soft start setting voltage stays high, and the
circuit enters the output short circuit detection wait state. Soft
start time (The time until the output ON duty reaches
approximately 50%) t
APPLICATION DIAGRAM
HOW TO SET THE TIME CONSTANT FOR SOFT
Bay Linear, Inc
START AND SHORT CIRCUIT DETECTION
S
2418 Armstrong Street, Livermore, CA 94550 Tel: [phone], Fax: [phone]
[s] @ 0.35 ´ CPE [mF]
B3800
Short Circuit Protection
load effect, the error amplifier output (FB pin) is fixed at
VOM + and capacitor CPE starts charging. When the
voltage at the SCP pin reaches approximately 0.8V, the
output pin is set low and the SCP pin stays low. Once the
protection circuit operates, the circuit can be restored by
resetting the power supply. • Short circuit detection time
T
If the switching regulator output suddenly drops due to
PE
[s] @ 0.8 ´ CPE [mF]
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B3800