MB3883

21

4.

Soft Start Operation

1. Description

• When the CTL, CTL1,2, CTL3, CTL4, and CTL5 terminals are driven high (“H” level) at the same time

The capacitor (C+IN6) connected to the C+IN6 terminal (pin 5) starts charging. When the C+IN6 terminal voltage

falls below 0.9 V (Typ.), the capacitor (Cs) connected to the CS terminal (pin 15) starts charging and the error

amp. provides a soft start by comparing the CH1 to CH5 output voltage to the voltage at the CS terminal.

t

0.9 V

2 V

2.49 V

1.25 V

(1) to (2)

(3) to (4)

Input

CTL (pin 20)

CTL1, 2 (pin 21)

CTL3 (pin 22)

CTL4 (pin 23)

CTL5 (pin 24)

Output

VB (pin 27)

C

+IN6 (pin 5)

CH6 output voltage

Vo6

VREF (pin 16)

CS (pin15)

CH1 to CH5 output

voltage Vo1 to Vo5

(1)

(3) (2)

(4)